center of micro

IMPRINT

PUBLISHED BY:Technische Universität IlmenauInstitute of Micro- and Nanotechnologies MacroNano®

© 2015

EDITOR:President of Technische Universität IlmenauUniv.-Prof. Dr. rer. nat. habil. Dr. h.c. Prof. h.c. mult. Peter Scharff

EDITORIAL OFFICE:Melanie BrunschSimone GutscheAnnika GuttzeitStefan KrischokJens MüllerStefano da RosKirsti SchneiderTino Wagner

COVER DESIGN:Büro für Gestaltung | formplusraum.de

PRINTING:PROOF „Druckproduktion“, Erfurt

PHOTOS, GRAPHS AND OTHER PICTURES:David Matthiesen, Michael Reichel (ari), IMN MacroNano®, TU Ilmenau, Ingo Herzog

Pictures, charts, drawings and text as used for the scientific articles are property of the corresponding authors.Any further use of text or images also in part requires the prior permissi-on of the authors.

3

Contents

Preface �� 4

The Institute and its Bodies �� 6

Highlights 2013 / 2014 �� 8

Presentation at Trade Fairs �� 10

International Contacts and Cooperation �� 11

Invited Talks �� 13

Large Format Projects �� 15

Center for Innovation Competence �� 15

Single Nanometer Manufacturing (SNM) �� 16

Core Facility “Micro-Nano-Integration” �� 17

Triangle of Expertise Optical Microsystems �� 18

BioLithoMorphie® �� 19

Carl Zeiss Project: Nanobiosystemtechnik �� 20

Carl Zeiss Project: SACCA �� 21

Competence Center �� 22

Research Unit: OptiSolar �� 24

DFG Research Unit FOR 1522 MUSIK �� 25

Bactocat �� 26

AIMS in OPV �� 27

Infrastructure Projects �� 28

XPS-Analytics �� 28

Deep Reactive Ion Etching tools for micro- and nanostructures �� 29

Scientific Projects �� 30

Project Statistics 2010 - 2014 �� 35

Center of Micro- and Nanotechnologies �� 36

Facts and Figures

Members of the Institute �� 41

Research Activities �� 85

4

Biannual Report2013 / 2014

FACTS AND FIGURES

Contact macronano@tu-ilmenau�de | www�macronano�de

The Institute of Micro- and Nanotechnologies MacroNano® (IMN MacroNano®) shapes with its work one of the six big interdisciplinary research clusters at our university: the re-search cluster Nanoengineering. The Micro-Nano Integrati-on allows new applications in life sciences, energy efficiency and photonics, which are fields particularly emphasized as “global challenges” by the Federal Ministry for Education and Research and mentioned in the document “High-tech Strategy for Germany“.

275 scientists and technicians from more than 40 groups work hand in hand in the IMN MacroNano®. The projects processed here at the interface of various scientific fields are of major importance for Technische Universität Ilmenau. These projects transfer basic research in Nanotechnologies and micro-systems technology into specific, concrete appli-cations. I would like to emphasize the projects supported by the Carl Zeiss Foundation and the Research Unit “3D-Nanostructuring“ federally funded as a Center for Innovati-on Competence. Here reasonably priced, three-dimensional and advanced nano-devices are developed.

PrefaceVorwort

Univ.-Prof. Dr. rer. nat. habil. Dr. h.c. Prof. h.c. Peter SCHARFF President of Technische Universität Ilmenau

The technological facility of the IMN MacroNano®, the Center of Micro- and Nanotechnologies, which also offers its infrastructure to third parties, has been funded with more than 500,000 euro by the Deutsche Forschungs-gemeinschaft (German Research Foundation) within the program “Gerätezentren – Core Facilities“ since 2013 for the next three years. Among 42 applicants, only ten were determined for funding as “Gerätezentren – Core Facilities“ and TU Ilmenau is among those ten selected. Today the Center of Micro- and Nanotechnologies is one of the only 21 “Gerätezentren – Core Facilities“ funded by the German Research Foundation throughout Germany. As the President of TU Ilmenau, I am proud to say that the IMN MacroNano® upheld its excellent reputation in Micro-Nano-Integration in Germany in 2013 and 2014. I trust that the institute’s future is very promising and rewarding, and its excellent reputation will have a positive impact on the entire university.

5


FACTS AND FIGURES


With this report we provide a summary of another two successful years of interdisciplinary research in the Institute of Micro- and Nanotechnologies IMN MacroNano® lieing behind us. We hope that the one page summaries of re-search topics give you a good impression of our scientific profile, although it is quite challenging to cover all aspects from fundamental research to applied and application ori-ented research with equal emphasis due to the large variety of scientific disciplines within our institute.At this point we would like to thank all of our members of the IMN MacroNano® who made this comprehensive report possible.For several years now we have experienced a stronger focus of research projects in the areas Materials for Micro- and Nanotechnologies, Micro-Nano-Integration, and 3D-Biosystems. These research areas provide solutions for appli-cations with much wider scope and address global aspects like green energy, life science, communication or mobility.In the reporting period internationally well recognized scientific results could be obtained in various research fields and third party funding at high level. In particular young researchers used the excellent environment of the IMN for interdisciplinary research very successfully as outlined by numerous graduations. At the same time significant steps have been achieved to improve the research infrastructure. Most of the installations in the clean-rooms in the Meitner building are finished and new equipment for deep reactive ion etching and analysis is ready to operate.The new processes and machines are also strengthe-ning the DFG-Core Facility Micro -Nano - Integrat ion which officially started its

PrefaceVorwort

Univ.-Prof. Dr.-Ing. Jens MÜLLER

current Director of the IMN MacroNano®

operation in 2014. Our aims to offer the expertise of the IMN MacroNano® for external users are to increase the level of utilization of the equipment on the one hand and to establish additional tight research links to other universities, research institutes and industry as a basis for new joint research projects on the other.Our institute members successfully organized international conferences and workshops related to Nanostructuring and Micro-Nano-Integration. The 1st International Conference on Challenges and Perspectives of Functional Nanostructu-res (July 29-31, 2014) was hosted by the Research Group 3D-Nanostructuring (Prof. Yong Lei) from the BMBF-Center for Innovation Competence (Unternehmen Region). It attrac-ted more than 100 participants and more than twenty top leading scientists in nanostructuring from all over the world. On the national level, Prof. Hoffmann, the chairman of the GMM-expert committee 4.7, invited guests to Ilmenau to attend the 5th GMM-Workshop on Micro-Nano-Integration between the 8th and 9th October 2014.In the upcoming years we will pursue to strengthen the interdisciplinary research within the IMN MacroNano® even further. Several concepts for large format projects including three or more research groups are already in the concept or planning phase. In addition, the IMN MacroNano® will play an active role in the transformation of the Master Micro- and Nanotechnologies into an international graduation

program.Dear reader, please enjoy this scientific report. We hope you will find interesting aspects for your specific research or work and invite you to con-tact us to discuss possibilities of future cooperation.

Univ.-Prof. Dr. rer. nat. habil. Stefan KRISCHOKcurrent Vice-Director of the IMN MacroNano

®

6


FACTS AND FIGURES


In the cross-faculty Master’s degree programs in “Micro- and Nanotechnologies” (the conversion into English language as an international Master s Degree Program is running at the moment) and “Miniaturised Biotechnology”, students from different undergraduate disciplines can extend their qualifications within the scope of the IMN MacroNano®. Postgraduate education is improved by the establishment of graduate research programs. In 2013 and 2014, 775 bachelor-, master- and diploma theses were prepared at the IMN MacroNano® successfully.The Institute strengthens its PhD program with regular events, including scientific colloquia and workshops on soft skills for early career scientists. These activities simultaneously intensify the network among the PhD candidates. The IMN MacroNano® offers direct support for early career scientists through the establishment of additional international groups. The multi-disciplinary research and development within the IMN offers various opportunities for industrial cooperation with small and medium sized enterprises as well as international companies. Among these are long term collaboration projects in consortia or projects with a single industrial partner, just as short term services. The internal project management and controlling efficiently supports even complex requirements.

The Institute of Micro- and Nanotechnologies IMN MacroNano® is an inter-departmental institute of the Technische Universität Ilmenau founded in 2005. Currently, the institute is formed by 40 groups of the Technische Universität Ilmenau from four faculties. The main focus of the institute is on bundling and coordinating interdisciplinary basic research up to applied technologies within the field of micro- and nanotechnologies. The scientific spectrum of the Institute spans from theoretical physicists and specialists in advanced electromagnetics to specialists in surface physics, polymer physics, chemistry and nano-biosystems all the way to experts in electronics technology, material science, optics and micromechanical systems, only to list some examples. This wide range makes the Institute unique at the national and international levels and gives the opportunity to map the entire development chain from simulation and design over fabrication of devices and systems by micro- and nano-structuring up to their characterization. In the last two years approximately 60 projects were edited at the IMN MacroNano®.Cutting-edge research and innovation are based on the high level of education attained by qualified young scientists and engineers at the Technische Universität Ilmenau. Consequently, the interdisciplinary approach of the Institute is also reflected in the offered lectures and courses of study.

The Institute and its BodiesDas Institut und seine Gremien

The current Executive Board of the IMN MacroNano®

7


FACTS AND FIGURES


The Executive Board of the Institute, also elected by the Institute Council, is assisting and advising the Director. Members of the Board with voting rights are besides the Director and Vice Director: Prof. Martin Hoffmann, Prof. Ivo Rangelow, Prof. Peter Schaaf, Prof. Stefan Sinzinger, Dr. Gernot Ecke, Dr. Michael Gebinoga, Lars Dittrich (successor of Dr. Marcel Himmerlich). The management team of the Center of Micro- and Nanotechnologies are consultants of the Executive Board without voting rights.The group of Technology-driving groups was initiated by the Executive Board and consists of 11 members: 3D Nanostructuring, Electronics Technology, Solid State Electronics, Micromechanical Systems, Micro- and Nanoelectronical Systems, Nanobiosystems Technology, Nanotechnology, Photovoltaics, Technical Optics, Technical Physics I, Materials for Electronics. They are distinguished as continuous users of the ZMN technologies including the advancing of the technologies.

The governing body of the Institute consists of the Director of the Institute, the Executive Board of the Institute (Institutsvorstand) and the Institute Council (Institutsrat).The Institute Council is responsible for defining the long-term-goals and the developmental focus of the Institute. Permanent members of the council are the chairs of member-groups of the institute. Additionally, there are eight academic representatives, one technical representative and one student representative. They are elected every three years.The Director of the institute is the Director of the Center of Micro- and Nanotechnologies (ZMN) at once. The election of the Director is executed by the Institute Council and appointed by the President of the University for a term of three years. The Director manages the Institute and represents it both inside and outside of the University. The current Director is Prof. Jens Müller and the Vice Director is Prof. Stefan Krischok.

The Institute and its BodiesDas Institut und seine Gremien

Organisation of the IMN MacroNano® and its bodies

8


FACTS AND FIGURES


16 October 2013Scientists of the groups Mechatronics and Mechanical En-gineering were awarded with the COSIMA (Competition of students in Microsystems Applications) price

6 to 22 November 2013„Kinderuni“; more than 100 children visited the ZMN

12 to 14 February 2014Kick-Off-Meeting of the project iMUSEUM and completion meeting of NanoBatt

17 to 19 March 201414th German Ferrofluid Workshop, Ilmenau

27 March 2014Workshop “Patenting of Nanotechnologies“ held by the famous patent agent Stefan R. Huebner from Munich, Germany

3 April 2014Lucia Lorenz was awarded with the „Green Photonics 2014“ price for her Masterthesis „Optische Abstands- und Schicht-dickenmessung entlang einer Linie“; Mathias Krüger was awarded by the SEW Eurodrive foundation for his Master thesis. Both are Optronics students.

26 April 2014Open Day at Technische Universität Ilmenau with guided visits to the ZMN laboratories

8 March 2013DPG-Ein Tag vor Ort: interested students visited the ZMN (organized by the Deutsche Physikalische Gesellschaft e.V. )

15 March 2013The large EU-project “Single Nanometer Nanufacturing beyond CMOS devices (SNM)“ started under the coordi-nation of Prof. Ivo Rangelow at the Technische Universität Ilmenau

20 April 2013 Open Day at Technische Universität Ilmenau with guided visits to the ZMN laboratories

14 May 2013Scientists of the Optical Engineering Group and the Micro- and nanoelectronics Systems Group are nominated for the famous AMA-price with their work on „Infrarot-Detektor basierend auf einem neuartigen Mikro-Spiegel-Sensor“

25 May 2013Long Night of Technique with guided visits to the ZMN laboratories

18 to 26 July 2013Nano-Orientation-Academy (NOrA) for young women

4 September 2013Workshop Deep Silicon Etching

Highlights 2013 / 2014Höhepunkte 2013 / 2014

Kick-Off-Meeting of the „DFG- Core Facility“ project (25 June 2014)

Columbian Mechatronic students visited the ZMN laboratories (30 September 2014)

9


FACTS AND FIGURES


7 October 2014Meeting of the GMM technical commitee „Aufbau- und Verbindungstechnik“

8 October 2014Meeting of the GMM technical commitee „Mikro-Nano-Integration“

8 to 9 October 20145th GMM Workshop on Micro-Nano-Integration

5 to 21 November 2014„Kinderuni“; more than 100 children visited the ZMN

25 November 2014The renowned climate scientist Prof. Hans Joachim Schelln-huber (Potsdam Institute for Climate Impact research) visited the ZMN

27 November 2014Status Meeting of the ZIK MacroNano® working group and the MetaZIK BioLithoMorphie

3 December 2014Nano-Imprint-Lithography Workshop

9 May 2014Visit of a delegation of the FH Heilbronn to explore coopera-tion and to get information about the workflow at the IMN MacroNano®

June 2014Dr. Harald Hoppe was honored as one of the top 1% re-searchers for most cited documents in the field of Materials Science by Thomson Reuters

12 June 2014René Böttcher (Materials Science) was awarded with the German Society for Non-Destructive Testing (DGZfP) price for his Bachelorthesis „Untersuchungen von Dickschicht-systemen mittels Ultraschall (Impuls-Echo-Verfahren) im Wasserbad und Signalverarbeitung mit der Fourieranalyse“

25 June 2014Kick-Off-Meeting Core Facility „Micro-Nano-Integration“ took place at the ZMN

8 to 12 Septmeber 201458th IWK Ilmenau Scientific Colloquium, Technische Univer-sität Ilmenau

30 September 2014Columbian Mechatronics students were visting the labora-tories of ZMN

Highlights 2013 / 2014Höhepunkte 2013 / 2014

Future researchers: Schoolkids are visiting the ZMN labs during Kinderuni (November 2014)

Visit of the famous climate scientist Prof. Hans Joachim Schellnhuber (25 November 2014)

10


FACTS AND FIGURES


Hannover Messe 2013, Hannover8 to 12 April 2013

Biotechnica 2013, Hannover8 to 10 October 2013

MST-Kongress 2013, Aachen14 to 16 October 2013

Hannover Messe 2014, Hannover7 to 11 April 2014

Sensor + Test 2014, Nürnberg3 to 5 June 2014

International Engineering Fair MSV 2014, Brno29 September to 3 October 2014

Glasstec 2014, Düsseldorf21 to 24 October 2014

Medica 2014, Düsseldorf12 to 14 November 2014

Presentation at Trade FairsMessebeteiligungen

IMN MacroNano® booth at MSV 2014, Brno

Visit of the Thuringian Minister-President Christine Lieberknecht at the IMN MacroNano® booth during Hannover Trade Fair, 2013

11


FACTS AND FIGURES


PeruThe first double degree master graduation “Werkstoff-wissenschaft / Ingenieria y Ciencias de los Materiales” was accomplished in March 2013 together with the partner Uni-versity Pontificia Universidad Católica del Perú PUCP. Up to now, six master students have graduated in materials science and engineering. In 2014, Katharina Loy, Theresa Berthold and Gisella Lucero successfully finished their master studies on the topics corrosion of titanium implant material, sputter coating of doped barium hexaferrite and silver nanoparticle immobilization in pillared clays for antimicrobial water treatment.

FranceAbout one dozen students are already using the opportu-nity to enrol in the joint German-French master program Micro-mechatronics between Technische Universität Ilme-nau and École Nationale Supérieure de Mécanique et des Microtechniques de Besançon (ENSMM) which was initiated by Prof. Martin Hoffmann. Graduated students can achieve the grade „Diplôme d’Ingénieur de l’ENSMM“ in addition to the German master degree within one semester. The first students finished this program successfully in 2013/2014.

International Contacts and CooperationInternationale Kontakte und Kooperationen

RussiaIn Kazan, the capital of the autonomous republic of Tarta-stan, the first German-Russian Institute of Advanced Tech-nologies (GRIAT) was opened on September 1, 2014. This is the first research institution administrated by two countries. Professors from both countries - Germany and Russia - will hold lectures at the GRIAT. In November and December 2014 four guest scientists from Kazan were working on projects at IMN MacroNano® within the group of Electronics Technology during their research stay in Ilmenau. The research topics of the group were fo-cused on RF-permittivity measurements for liquids (e.g. oil) and nano analytics to investigate new functional materials during the four weeks stay.

Various international guests and delegations visited the IMN MacroNano® in the reporting period:

IndonesiaUnder the direction of the Technische Universität the „International University Liaison Indonesia (IUIL)“ was foun-ded in 2014. In March 2014, the Indonesian ambassador in Germany, his Excellence Dr. Fauzi Bowo and the chairman of the IUIL foundation Dr. Ilham Habibie visited the laboratories of the ZMN.

Double degree Master student Theresa Berthold (center) and the examination committee Nam Gutzeit (TUILM), Prof. Dr. Roland Weingärtner (PUCP), Dr. Bernd Halbedel (TUILM), and Prof. Dr. Edda Rädlein (TUILM)

Guest scientists from Kazan are visiting their temporary work-place

12


FACTS AND FIGURES


MoroccoDuring their study tour of Photovoltaics and Concentration Solar Power innovations, a delegation of several moroccan scientists working in the fields of solar energy were visiting the IMN MacroNano® in May 2014. They were interested in latest research activities in the field of solar energy as well as in the institute s activities.

MexicoIn November 2014 a group of 17 directors from several technical and polytechnical universities were visiting the IMN MacroNano®. Organized by the DAAD (Deutscher aka-demischer Austauschdienst), participants of this delegation were guided through the cleanroom laboratories in the house to get an impression of the interdiscplinary work at the institute, the technical facilities within the labs as well as current research topics of the IMN MacroNano®.

ChinaOn June 2nd 2014 a delegation from China National Software and Integrated Circuit Promotion Center (CSIP) of Ministry of Industry and Information Technology visited the IMN/ZMN. They were interested in the structure and organisation of the IMN MacroNano®, the scientific work at the institute as well as in the correlation to the Center of Micro- and Nanotechnologies.

International Contacts and CooperationInternationale Kontakte und Kooperationen

Members of this delegation offered several possibilities for scientific cooperations. Furthermore, they were interested in the exchange of guest lecturers from and to Technische Universität Ilmenau.

The 1st International Conference & 3rd International MacroNano-Colloquium on the Challenges and Per-spectives of Functional Nanostructures (CPFN)To stimulate a broad international dialogue on the recent development and potential applications of functional nanos-tructures, the ZIK (Center of Innovation Competence) group 3D Nano-Structuring in the Institute for Micro- and Nano-technology (IMN MacroNano®) at the Technische Universität Ilmenau convened a conference. The 1st International Con-ference & 3rd International MacroNano-Colloquium on the Challenges and Perspectives of Functional Nanostructures (CPFN), on July 29th –31st, 2014 at the TU-Ilmenau.The conference, which involved public presentations and discussion among over 100 registered participants, was aimed to discuss new concepts and techniques of nanos-tructures to solve fundamental crosscutting topics for ad-vanced applications of energy-related, optical and electronic devices. It brought together over 20 top scientists from all over the world to introduce their breakthrough research results within the related fields.

The Technische Universität Ilmenau was introduced to the Chinese Delegation by its President Prof. Peter Scharff

13


FACTS AND FIGURES


Dipl.-Phys. Andrea Knauer Technische Universität Ilmenau“Kontinuierliche Mikrodurchflusssynthese komplex strukturierter und formanisotroper Edelmetallnanopartikel in Mikrofluidsegment-Sequenzen”

Prof. Dr. Hermann Kohlstedt Christian-Albrechts-Universität zu Kiel“Memrestive devices in analog neuromorphic circuits“

Dr. Alexander Konkin Technische Universität Ilmenau“Beispiele für die Anwendung der Elektronenspinresonanz an der TU Ilmenau”

Prof. Dr.-Ing. Alfred Ludwig Ruhr-Universität Bochum“Fabrication and characterization of thin film materials libraries for the development of new materials“

Prof. Dr. Eberhard Manske Technische Universität Ilmenau“Aktuelle Tendenzen der Nanopositionier- und Nano-messtechnik”

PD Dr. Thomas Ortlepp Forschungsinstitut für Mikrosensorik und Photovoltaik GmbH, Erfurt“Forschungs - und Entwicklungsaktivitäten am CiS Forschungsinstitut: vom Silizium-Chip zum Sensor-Mikrosystem”

Prof. Gianluca Piazza Carnegie Mellon University, Pittsburgh, USA“Piezoelectric resonant microdevices for programmable radio front-ends“

Dr. Melanie Brunsch Technische Universität Ilmenau“Mikro und Nano mal anders: Ein Exkurs in die Biologie”

Dr. Grigoryi Dmytriv Ivan Franko Lviv National University Ukraine“New intermetallic compounds: structural, hydrogenation and electrochemical properties“

Dr. Silvio Dutz Technische Universität Ilmenau“Magnetische Nanopartikel für biomedizinische Anwend-ungen”

Dipl.-Phys. Eva Gartzke Siemens AG, München“Integrierte Transformatoren für Umrichtungsschaltungen”

Prof. Dr. Horst Hahn KIT Karlsruhe“Reversible tuning of materials properties by external fields“

Prof. em. Rudolf P. Hübner Universität Tübingen“Die Geburt der Quantenphysik - Boltzmann, Planck, Einstein, Nernst und andere”

Dr. Alexander Groß Technische Universität Ilmenau“Droplet-based microfluidics for synthesis and screening“

Dr. Dmitry Kholodnyak St. Petersburg Electrotechnical University “LETI”“Advanced microwave filters for multi-band wireless applications“

Invited TalksVorträge im Institut

The institute continuously invites national and international colleagues to present their research results in the framework of a series of invited talks� Usually, approaches and results of conjoint projects are shown as well as research topics of the invited speaker with a direct relation to the topics of the IMN MacroNano®� If you are interested in detailed information about the topics and guest speakers, please contact the advisory committee (zmn@tu-ilmenau�de)

14


FACTS AND FIGURES


Invited TalksVorträge im Institut

Prof. Dr. Eugen Rabkin Israel Institute of Technology, Haifa, Israel“From thin films to nanoparticles: microstructure, kinetics, mechanics”

mgr inz. Artur Rydosz Katedra Elektroniki, AGH Krakow, Poland“Metal oxide nanostructures for gas detection“

Dr. Helmut Schift Paul Scherrer Institut, Villigen, Switzerland“Nanoimprint Lithographie: Prägen statt Belichten”

M.Eng. Cindy Steiner Frauenhofer Institut für Elektronenstrahl- und Plasmatech-nik FEP, Dresden“Optische Entspiegelung von Kunststofffolien”

Dr. Alexander Weber-Bargioni University of California Berkeley, USA“Mapping optoelectronic properties of nano building block assemblies at their native length scale“

Prof. Dr. Martin Wegener KIT Karlsruhe“Transformieren und Tarnen”

Dr. Lars Wegner KIT Karlsruhe“Elektrische Feldeffekte an Membranen - Spannung ist garantiert”

Prof. Dr. Roland Weingärtner Pontificia Universidad Catolica del Peru“Wide bandgap semiconductors doped with rare earths and their optoelectronical applications“

Invitation sheet to the colloquium

15


FACTS AND FIGURES


Center for Innovation CompetenceZentrum für Innovationskompetenz (ZIK)

The program „Center for Innovation Competence“ turns outstanding research approaches at universities and research insti-tutions in the New German areas into internationally renowned centers� Excellent and internationally competitive research, as well as „innovation competence“ or the ability to transfer research findings to the economy, are essential for these cen-ters, which should also act as a magnet for young scientists� (Quotation from the BMBF-Website: www�unternehmen-region�de/en/350�php)

The foundation of the Center for Innovation Competence „ZIK MacroNano®” at our institute in 2006 enabled us to establish several new research topics. The ZIK starts with the Junior Re-search Groups „Functionalised Peripherics” and „Microfluidics & Biosensors”. Meantime the former leaders of the groups are appointed professors of the university. To permanently secure the success of the Centers for Innovation Competence, the BMBF issued a second round of financing in summer 2009. This way the center got additional financial support from the BMBF and the TU Ilmenau has accommodated a new Junior Research Group „Three dimensional Nanostructuring“ at the ZIK.The junior research group is equipped with start-up funding for five years (2012 - 2016), including positions for additional scientific collaborators and for investment and running ex-penses. The leadership of this junior research group has been taken by Prof. Dr. Yong Lei, as an Associated (W2) Professor and is also the head of a group at the Faculty of Mathematics and Natural Sciences. In the broadest sense, nano-devices are the critical promoters that will allow mankind to exploit the complete technological capabilities of electronic, magnetic, mechanical, biological and especially energy-related systems, which have high impacts to enhance energy conversion, controlling pollution, producing food, and improving human health. In order to exploit nanometer-scale phenomena in devices, it shall have a better understanding of the electronic, magnetic, and photo-nic interactions that occur on this size scale. Meanwhile, we

believe that it will become possible to integrate nano-devices into functional circuits and chips. Therefore, the realization of different three-dimensional (3D) nanostructures on suitable substrates is a very important and highly challenging topic within the nanotechnology field. The Junior Research Group „Three dimensional Nanostructuring“ is responsible for developing efficient and low cost processes to design and fabricate 3D nano-devices. Ultra-thin alumina mask (UTAM) surface patterning technique provides an approach to prepare large-scale ordered surface nano-patterns. Combined with advanced equipments (e.g., atomic layer deposition, physical vapor deposition and elec-trochemical deposition), various promising 3D nano-devices are fabricated and integrated, mainly including gas sensors, memory devices, high performance super-capacitor and solar fuel cells. Appropriate simulation methods are utilized for better understanding and optimizing of the properties of na-no-devices. Most importantly, the properties of nano-devices are systematically investigated and their fabrication processes are well engineered for potential commercial products. After nearly 3 years of the project running, the group has received many excellent results following from about 30 scientific SCI-indexed publications, and many of these papers were published in top-level journals with impact factor higher than 10, such as Advanced Materials, Angewandte Chemie, ACS Nano, Nano Energy, Nature Communications, Journal of the American Chemical Society, and Advanced Functional Materials.

Contact:Prof. Dr. Yong Lei Technische Universität Ilmenau

P.O. Box 10 05 65

98684 Ilmenau

Phone +49 3677 69-3748

Fax +49 3677 69-3746

yong�lei@tu-ilmenau�de

http://www.tu-ilmenau.de/nanostruk/

16


FACTS AND FIGURES


Silicon transistors used in Integrated Circuits (IC) have been reducing steadily in size for over 40 years. From the very beginning in the 1960s, Gordon Moore predicted that the number of transistors on a silicon chip would double every two years. This trend, the famous Moore’s law, has become a self-fulfilling prophecy, driving industry requirements for each new generation of silicon chips and leading to drama-tic increases in the speed and performance of integrated circuits. Here, the basic circuit building blocks are semicon-ductor transistors, devices that act as valves to control the circuit current. Each transistor contains a ‘channel’ region where current can flow. This current can be switched on or off by a voltage applied to a ‘gate’ region in close proximity to the channel, allowing charge to be controlled and trans-ferred within the circuit.The aim of the Single Nanometer Manufacturing (SNM) project is to investigate and develop novel Technologies for Single Nanometer Manufacturing, reaching the theoretical limit of future nanoelectronic and nanomechanical systems. Moore’s Law has been the basis in long-term planning in the technological developments, resulting in an exponential

Single Nanometer Manufacturing (SNM)SNM is an integrated research project funded by the European Commission’s Seventh Framework Programme FP7/2007-2013 under Grant Agreement No� 318804 (Single Nanometer Manufacturing for beyond CMOS devices)�

Spokesman: Prof. Dr.-Ing. habil. Ivo W. RangelowMicro- and nanoelectronic Systems Group

Fig. 1: Dot exposure test wherein the dot diameter was modulated from 100 nm to sub-10 nm (realised by M. Kästner, MNES)

Fig. 2: Layout of SET-devices created with Scanning Probe Lithography (realised by C. Aydogan, MNES )

Funding: EU, FKZ: 318804

Contact:Technische Universität Ilmenau

P.O. Box 10 05 65

98684 Ilmenau

increase in the number of transistors Si-MOSFET per chip. SNM will contribute to next generation nanomanufacturing technologies, for building future quantum electronics and pushing this nanotechnology into many new areas (Fig.1). Numerous exploratory research innovations that could lead to major advancements in delivering radically smaller, faster and more powerful computer chips are considered.High performance Single Nanometer Manufacturing is an enabling technology for nanoelectronics, capable to open new horizons in the emerging world of nanotechnology. Sustainable competence and excellence in the project should secure a new path for manufacturing ultimate electronic, optical and mechanical devices never done before. A 18 member strong team from industry, academia and research institutes, led by Department of MNES at the Technische Uni-versität Ilmenau is working together in an integrated project (IP) to achieve ambitious goals: Enabling of novel ultra-low power electronics, quantum devices and manipulation of individual electrons (so called Single Electron devices, Fig.2).

Phone +49 3677 69-3717

ivo�rangelow@tu-ilmenau�de

http://www.tu-ilmenau.de/snm-project

17


FACTS AND FIGURES


Core Facility “Micro-Nano-Integration”

Spokesman: J. Müller1, M. Hoffmann2, P. Schaaf3 1 Electronics Technology Group2 Micromechanical Systems Group3 Group of of Materials for Electrical Engineering and Electronics

Funding: German Research Foundation (DFG), under contracts MU 3171/2-1, HO 2284/4-1, SCHA 632/19-1

In December 2013 funding of the project “DFG Core Facility Micro-Nano-Integration” at the Institute of Micro- and Na-notechnologies (IMN) MacroNano® started.This project is part of the funding line “Core Facilities“ of the German Research Foundation (DFG). With this initiative DFG supports a broad utilization of core facilities and networks of national and international significance and underlines the scientific visibility of the IMN MacroNano®.The goal of the project is to increase the efficiency of the Center for Micro- and Nanotechnologies (ZMN) as a Core Facility “Micro-Nano-Integration” and to make the existing comprehensive set of technologies and the scientific com-petence accessibly to a much wider circle of scientific users.The eminent characteristic of the project in Ilmenau is not to offer one single piece of sophisticated scientific equip-ment; it is instead to encourage users to take advantage of the unique combination from nanoprocessing to systems technology including the appropriate analytics which ac-companies the processes.This should make it possible for users, on the one hand, to generate nanostructures with new functionalities within systems and devices, or on the other hand, to integrate new

nanostructures in already existing micro systems.Through the use of adapted organisational structures and decision processes we pursue the following goals:

• easier access to IMN MacroNano® processes and tech-nologies for TU Ilmenau internal and external research partners (e.g. groups outside the IMN and external research institutes and institutions)

• improvement and optimal utilization of the interdiscip-linary expertise of IMN-groups

• enhancement of the professionalism of the laboratory organisation and research

The emphasis lies in the development of a professional, scientifically adequate management of the core facility. Aspects of reproducibility along defined process lines are given careful consideration. A transparent application-, de-cision- and accounting-making structure will provide easier access for users. Due to the fact that offered all-inclusive costs can be directly included in DFG project proposals, it simplifies the project application process for potential core facility users.

Phone +49 3677 69-3302

tino�wagner@tu-ilmenau�de

http://www.tu-ilmenau.de/core-facility-mni

Contact:Tino WagnerTechnische Universität Ilmenau

P.O. Box 10 05 65

98684 Ilmenau

18


FACTS AND FIGURES


Triangle of Expertise Optical MicrosystemsKompetenzdreieck OptiMi

Ziel des Projektes OPTIMI ist der Aufbau von gemeinsamen Technologieplattformen und insgesamt fünf Demonstrator-Systemen, die Anwendungen in den Bereichen Produktion/Maschinenbau, Lebenswissenschaften und Umwelt adressieren� Im Demonstra-tor D2 werden neue optische Mikrosysteme entwickelt, die in einzigartiger Weise mechanische, optische, fluidische und elektro-nische Funktionen vereinigen�

Project fundingin the framework program „Microsystems“BMBF,FKZ: 16SV3700

Project period:01.07.2008 to 31.12.2013Extension filed

Total amount:ca. 5.2 mil. Euro (TUIL part)

Project coordinator:Friedrich Schiller University JenaProf. Dr. Andreas Tünnermann

Project partners:• Friedrich Schiller University Jena• Technische Universität Ilmenau• CiS Research Institute for Micro Sensors and Photovol-

taics GmbH, Erfurt

Strategic partnership:• Leibniz Institute of Photonic Technology (IPHT Jena)• Application Center of Micro-Optical Systems (amos)• Center for Advanced Microsystems and NanoOptics

(CMN)• Important national co-operation partners include

several Max Planck Institutes, such as the MPI for Quantum Optics in Munich, MPI for Applied Computer Science (Karlsruhe Institute of Technology), MPI for Gravitational Physics (Albert Einstein Institute) in Hannover and the Max Planck Working Group Optics, Information and Photonics Erlangen-Nuremberg

• Multiple institutes of the Fraunhofer-Society are also important partners in research: the Fraunhofer Institute for Applied Optics and Precision Engineering (IOF, Jena), the Fraunhofer Institute for Physical Measurement Techniques (IPM, Freiburg) and the Fraunhofer Institute for Applied Solid State Physics (IAF, Freiburg)

Contact at the Technische Universität Ilmenau:Prof. Dr. Martin Hoffmann Institute of Micro- und NanotechnologiesTU IlmenauGustav-Kirchhoff-Str. 7D-98693 IlmenauGermany

[email protected]: +49 3677 69-2487Fax: +49 3677 69-1840

Scientific goalsOptical microsystems combine optical functionality with sensors and actuators on the microscale, but the systems design has always to pay attention to the fields of appli-cation. This requires highly interdisciplinary cooperation. Within the triangle of expertise, the Ilmenau partners were responsible for the systems integration aspects as well as for the micromechanical component development. On one hand, optical microsystems allow for compact devices in production technology: a new mirror module is developed that allows phase correction in high power laser systems, e.g. in laser welding or cutting. Combining at least three interferometers with low-power lasers and beam deflecting mirrors results in a microtracker system that can follow a moving tool center pointefficiently by trilateration. On the other hand, light is an efficient tool investigating the behavior of biological system. Within the subproject Optoflutronics microfluidic systems, especially cultivation systems for cells are equipped with a multi-wavelength sensor platform. Nowadays, the unification of complex microoptics and biocompatible microfluidics in a single component is still a challenging task. Interdisciplinary researchAs the chosen demonstrators are complex systems, new ways of cooperation have successfully been proven. At first, the strengths of the three sites in Jena, Erfurt and Ilmenau were combined. But also within the IMN MacroNano® the expertise of several research groups was involved in this project: Techno-logically oriented partners design and fabricate different types of mirrors, interferometers and microfluidic systems. Further groups combine these components into systems and develop systems software for control. And finally, partners set up test environments for demonstrators with their unique expertise in applications. Here, the strong interdisciplinary structure of the IMN MacroNano® is a key to success of those projects. Although the funding ended in 2013, new ideas are currently investigated and first projects that are based on ideas that came up during this project were started. The funding ended, but a successful network was established and will go on with new ideas! Don‘t hesitate to contact the IMN MacroNano® with your ideas concerning optical micro-systems. The team will propose a suitable way to realize your idea!

19


FACTS AND FIGURES


BioLithoMorphie®

Assemblierung biologischen Materials mit Hilfe lithographischer Metho-den zur Konstruktion dreidimensionaler biologischer Morphologie

Spokesman: Prof. Dr. rer. nat. habil. Andreas SchoberNano-Biosystems Engineering Group

Contact: Technische Universität Ilmenau

P.O. Box 10 05 65

98684 Ilmenau

Phone +49 3677 69-3387

andreas�schober@tu-ilmenau�de

http://www.tu-ilmenau.de/nbs

BioLithoMorphie® is defined as the assembly of biological materials for the construction of 3D biological morphologies with the help of methods of the micro- and nanotechnology (e.g. lithographic tools).BioLithoMorphie® is a joined initiative of the center of ex-cellence MacroNano® and B Cube fusing expertise of micro and nanotechnologies with the expertise in the design of biomimetric materials. Analog to growth and degradation processes in nature BioLithoMorphie® transfers methods of micro- and nanotechnologies (as additive and subtractive processes for the construction of devices) to the construc-

Fig. 1: Microfluidic system for 3D cell cultivation (left), Biofunctionalization of polymer surface (middle, right)

Fig. 2: A) Mono-directional switching of cell adhesive ligand, as compared with the prototyping methods B) polycarbonate procession technology as well as surface chemistry for high throughput production of the 3D cell culture systems

Funding: BMBF PTJ, FKZ: 03Z1M511

tion of 3D tissue like structures. We are committed to pro-vide techniques for system design, structuring, lithographic and chemical modification of the desirable surfaces. This way we are able to obtain complex extracellular structures by using mechanical modification of thin polymer foils at micron scale and chemical modification at submicron scale. BioLithoMorphie® aims to model the biological systems for biomedical applications ranging from drug screening to regenerative therapy. It will also shed new light on the basic biology including cell differentiation and organ deve-lopment.

20


FACTS AND FIGURES


Carl Zeiss Project: Untersuchung von Zellen mit neuartiger hybrider funktionalisierterBiosensorik in drei Dimensionen

Spokesman: Prof. Dr. rer. nat. habil. Andreas SchoberNano-Biosystems Engineering Group

There is an increasing demand for integrated systems for biological applications. Recently, 3D cell cultivation and mimicking organo-type cell culture has become a central theme for biotechnology and tissue engineering. Such cell cultivation devices with integrated sensor functions can only be achieved by a highly interdisciplinary scientific approach. Within the Carl Zeiss Project „Untersuchung von Zellen mit neuartiger hybrider funktionalisierter Biosensorik in drei Dimensionen“ three groups joined for establishing this in-novative approach examining cell behavior. The groups of Andreas Schober (Nanobiosystemstechnology (NBS) with expertise in microfluidics and biosensors), Heiko Jacobs (Na-notechnology (NT) with expertise in flexible electronics and material sciences) and Stefan Krischok (Technical Physics I with expertise in surface sciences) applied for this collabora-tive project which at least should lead to 3D scaffolds with integrated sensors. The 3D scaffolds for cell cultivation pro-duced by NBS are named MatriGrids. Furthermore all three groups have expertise in the application, manufacturing and analysis of Group III semiconductor devices which can

Fig. 1: A) Metal contact embedded foil B) Thermoforming process C) Processed MatriGrid with embedded electronics


P.O. Box 10 05 65

98684 Ilmenau

Phone +49 3677 69-3387


http://www.tu-ilmenau.de/nbs

Funding: Carl Zeiss Foundation, FKZ: 0563-2.8/399/1

serve both as electrical and optical sensor elements which should be integrated in polymeric scaffolds. Besides exami-nations with respect to the latter material class NBS and NT examined the possibility to integrate metallic components within a thermoplastic polymer (Figure, A) which is then in the next step formed by a thermoforming process (Figure, B). This results in a new substrate which one can define as e-MatriGrid. This means for the complex polymer structure that the metallic contacts need to get stretched during the polymer forming process without destroying the connec-tions. In order to solve this problem we need to address the following issues: choice of the polymer, structuring of metal contacts, transfer of the metal structure on polymer substrate, lamination of polymer films, structuring polymer scaffolds, testing contacts and performance. This deman-ding task now has been realized in first structures embed-ded in the polymer (Figure, C).Within the scope of this work is the functionalization and the analysis of polymers for chemical and biological and enginee-ring applications.

21


FACTS AND FIGURES


At present, systematic development of equipment for cell cultivation and analysis is primarily based on statutory requirements for biomedical technologies, especially strict prescriptions to document the design processes, which are enforced by Medicinal Devices Act. SACCA is implementing systematization not only in the state of development, but already in research: consistent application of VDI guideline 2206 (‘Design methodology for mechatronic systems’) streamlines and therefore facilitates transition of research results into preproduction development.Since the system concept is ‘bio-centered’ rather than ‘technology-centered’, a great level of progress is estima-ted. To date, cell cultures, which need to be analyzed, are transferred from an incubator to an analysis workplace. When cells of the musculoskeletal system (bone, cartilage, tendons, muscle) are analyzed, forces are regarded as crucial for differentiation. Repeated and arbitrary appearance of forces during transport processes might be fatal; in a long-term study they might produce wrong and corrupt research results. For this reason, SACCA uses stationary cell cultures, while technical devices move to the place of analysis – a ‘bio-centered’ approach.

Even in the ‘century of biology’, in most cases cell cultures are still handled manually. Regarding automation of proces-ses, cell biology is in a state resembling the one of industry in the beginning of the 19th century – manufactories are dominating a seminal field of research and a growing in-dustrial sector.Thanks to support and funding by Carl Zeiss Foundation, TU Ilmenau is able to boost the sector of cell cultivation by utilizing twenty-first century automation technologies in a project named SACCA (System for Automated Cell Cultiva-tion and Analysis). In a cooperation of four departments of IMN MacroNano® and iba (Institut für Bioprozess- und Analysenmesstechnik e.V.) Heilbad Heiligenstadt methods of mechatronics and microsystem technologies are used to develop an automated laboratory unit for cell cultivation. Preliminary works funded by the German federation, e. g. DFG Collaborative Research Center 622, as well as the federal state of Thuringia (Fig. 1), are continued seamlessly. Lead-managed by Department of Biomechatronics and granted with 1 million Euro, substantial contributions for the establishment of a new Collaborative Research Center regarding BioMOEMS (Bio-Micro-Opto-Electro-Mechanic Systems) are made by IMN MacroNano®.

Carl Zeiss Project SACCA: System for Automated Cell Cultivation and Analysis

Fig. 1: State of the art – current experimental setup for cell cultivation in single micro systems

Fig. 2: Schematic of SACCA workbench: analytic devices move around stationary cell cultures in microsystems


P.O. Box 10 05 65

98684 Ilmenau

Phone +49 3677 69-2456

hartmut�witte@tu-ilmenau�de

http://www.tu-ilmenau.de/sacca/

Spokesman: Prof. Dipl.-Ing. Dr. med. (habil.) Hartmut WitteBiomechatronics Group

Funding: Carl Zeiss Foundation, FKZ 0563-2.8/416/3

22


FACTS AND FIGURES


Competence Center “Nanopositioning and Nanomeasuring Machines”

Spokesman: Prof. Dr.-Ing. habil. Eberhard ManskeInstitute of Process Measurement and Sensor Technology

The competence center “Nanopositioning and Nanomeasu-ring Machines” (CC NPMM) at the Technische Universität Ilmenau arose from the collaborative research center SFB 622, supported by the German Research Foundation from 2002 to 2013. Nanopositioning and nanomeasu-ring technology is a primary research area at the TU Ilmenau. The collaborative research centre 622 is integra-ted into two of the six research clusters at the University:

• Nanoengineering• Precision technology and precision metrology.

The enormous potential of cutting-edge technologies such as nanotechnology and high-end optical technology represents one of the primary foundations for mastering the economic and social challenges of the 21st century. For these technolo-gies speed and efficiency are increasingly determined by the availability of high-performance devices. The production and especially the analysis of larger and larger objects with nano-sized structures and properties – from semiconductor and micro-systems technology to precision optics and bio-analysis – require new concepts in three-dimensional nanopositio-ning and nanomeasuring technology. While 2-D positioning and 2.5-D measuring technology have been sufficient up to now for the semiconductor industry, additional traceable positioning and nano-precision measurements in the third dimension have been gaining significance because of the in-creasingly complex spatial structures in micro-systems techno-logy, precision optics as well as in semiconductor metrology.

Therefore, the goal of CC NPMM for the next years invol-ves the formulation of the scientific fundamentals for technological apparatus allowing the positioning, contact, measurement, analysis, modification and manipulation of three-dimensional objects in the volume range up to 450 x 450 x 80 mm³ with nanometre precision. In order to achieve this goal, sophisticated theoretical and experimental inves-tigations must be performed into innovative components and into the entire behaviour of nanomeasuring machines.

Fig. 1a: Close-up of the Nanopositioning and Nanomeasuring Machine

Fig. 1b: Nanopositioning and Nanomeasuring Machine

23


FACTS AND FIGURES


Competence Center “Nanopositioning and Nanomeasuring Machines”

Contact:

Technische Universität Ilmenau

SFB 622

P.O. Box 10 05 65

98684 Ilmenau

Phone +49 3677 69-5051

Fax +49 3677 69-5052

SFB622@tu-ilmenau�de

http://www.tu-ilmenau.de/cc-npmm/

Seit 2013 besteht das aus dem Sonderforschungsbereich 622 hervorgegangene Kompetenzzentrum „Nanopositionier- und Nano-messmaschinen“ an der TU Ilmenau� Aufgabe ist es, technische, technologische und analytische Operationen mit höchster Präzisi-on und Dynamik auszuführen� Die großen Herausforderungen bestehen darin, dass die Nanopositionier- und Nanomessmaschinen Forderungen nach immer größeren Bewegungsbereichen mit extremen Genauigkeiten und hohen Positioniergeschwindigkeiten ge-nügen müssen� Außerdem sind zu entwickelnde neuartige Antastsysteme und Nanotools (Bearbeitungstools) in die Nanopositionier- und Nanomessmaschinen einzubinden�

The nationally and internationally published results of SFB 622 and CC NPMM to date regarding nanopositioning and nanomeasuring systems were the driving force for the intensive, globally relevant research work in the area of 3-D nanopositioning and nanomeasuring technology. The com-petence center is able to fulfil its leading technological role by the consistent analysis and implementation of low-error met-rological and device-oriented fundamentals for simultaneous measurement and active control of the guide deviations as well as for the usage of innovative high-performance optical measurement and probe systems. Successful handling of the exacting, complex tasks has become possible on the one hand through the competency and the tight integration of the scientists within the CC NPMM itself, but also through the intensive scientific contacts of the members with national and international research institutes.The Center’s ambitious goals can only be met through optimal cooperation among many different subject areas, including metrology, measurement technology, nanoanalytics, drive technology, mechanics, optics, electronics, design, materials science, control engineering as well as signal processing.

Capabilities of CC NPMM: • Expertise in the development of new and adapted measurement, probe and positioning systems for micro- and nanotechnologies• Integration of customer-specific contact sensors and micromachining tools into the Nanopositioning and Nanomeasuring Machine • Solution to metrological problems in the micro- and nanoranges

Metrological services:• Measurement of micro- and nano-objects and structures with various contact and non-contact sensors• Probing methods: focus sensors, white-light microscopy, metrological atomic force microscopy, profiling sensor, 3-D microsensor• Measurement of microelectronics structures as well as structures formed using nanoinprint technology• Measurement of precision optics (aspheres, free-form surfaces) with the help of fast surface scans (5 mm/s) with nanometre uncertainty

Fig. 2: Networking of projects in the CC NPMM

24


FACTS AND FIGURES


Research Unit: OptiSolar

Object of research: to increase the reliability and efficien-cy of silicon solar cells through the optimization of critical boundaries.The decline of potential induced degradation (PID) is a key problem to protecting and increasing the product reliability of photovoltaics (required product life span > 25 years) and leads to a higher cumulative yield in energy over the entire life span of the solar module.The research group works on three subareas: (i) solar cells with a-Si:H heteroemitter with a minimum of 22% efficiency; (ii) the analysis of the PID effect, the creation of a physical se-miconducting model as well as the development of provisions for rectification; and (iii) the transfer of intrinsic heterojunc-tion from (i) to laser crystalized thin-film silicon solar cells.A SiN-interlayer between the silicon and glass substrate is thereby necessary. This SiN-interlayer‘s properties should be optimized in such a way that both the PID effect is prevented

and, at the same time, the conditions for laser crystallization are withstood.All research occurs in close cooperation with the research group working in parallel on „Increasing the reliability and efficiency of PV through optimization of SiNx:H/Si critical boundaries (PIDSINX:H)“ (Coordination: CiS GmbH Erfurt). Together, the groups’ complementary research enables a comprehensive study of the PID effect.Results: Substantial progress was made in all three areas. In subarea (i) energy conversion efficiency up to 21.3% has been achieved thus far. In subarea (ii) the characteristic de-gradation, which indicated the occurrence of the PID effect, can be attributed to the development of areas with enhanced recombination in stacking faults by the enrichment of sodium.An efficiency of over 11% was achieved in subarea (iii) with the successful transfer of HIT technology to laser crystalized solar cells.


P.O. Box 10 05 65

98684 Ilmenau

Phone +49 3677 69-2566

thomas�hannappel@tu-ilmenau�de

Spokesman: Prof. Dr. rer. nat. habil. Thomas HannappelPhotovoltaics Grouphttp://www.tu-ilmenau.de/pv/

Funding: TAB, FKZ: 2012 FGR 0231

Fig. 1: Influence of the PID effect with increased damage of a Si- solar cell on its current-voltage characteristics

Fig. 2: Current-voltage characteristics of a laser crystalized Poly-Si-solar cell with n-endowed absorber and p-endowed a-Si-emitter

[1] L. Mazzarella et al., APL, 106, 023902 (2015); O. Gabriel et al. WCPEC-6, Kyoto, 27th Nov. 2014[2] Lars Winterfeld, Hartmut Übensee, Mario Bähr: “Influence on the solar cell performance of Na contamination in Si/SiO/SiN interfaces and in Si stacking faults” (2015), in preparation[3] Industriebeirat: Solarworld Innovations GmbH (ersetzt das frühere Mitglied Bosch Solar Energy AG), Masdar PV GmbH, Roth & Rau AG, CEM Concept GmbH

25


FACTS AND FIGURES


DFG Research Unit FOR 1522 MUSIKMultiphysical Synthesis and Integration of Complex RF Circuits

Starting in the end of 2012, the DFG research unit MUSIK pursues the integration of micro-electro-mechanical system (MEMS) devices, as resonators and switches, with active and passive electric and electronic components to realize complex radio frequency (RF) circuits. The design of such systems com-bined from micro-electronic and micro-mechanic elements demands novel design strategies and tailored circuit techno-logies referred to as “RF micromechatronics”. The research focus lies on an application-oriented system level, e.g., for mobile communications, away from previous approaches related to single-device or technology optimization. MUSIK is organized in eight interdisciplinary subprojects located at the RF & Microwave Research Laboratory (HMT), the Electro-nic Circuits and Systems Group (ESS), the Micromechanical Systems Group (MMS) and the Electronics Technology Group (ET) at Technische Universität Ilmenau; the Chair for Technical Electronics at Friedrich-Alexander-Universität Erlangen-Nürn-berg; and the Institute for Microelectronic and Mechatronic Systems GmbH (IMMS) at Ilmenau. Assisted from software tools, e.g., Coventor MEMS+, ANSYS, the MUSIK team de-velops compact parameterized multi-physical MEMS device models which also include parasitic and non-linear effects from analytical formulae, numerical simulations and mea-surement data evaluation. Integration of such models into state-of-art circuit and system simulators, namely, Cadence Spectre and Keysight ADS, provide for the RF system design, analysis and optimization at multiple abstraction levels (Fig. 1). Simultaneously, the development of a technology plat-form based on Silicon-Ceramic compound substrates (SiCer), originally investigated at the IMN MacroNano® at Technische Universität Ilmenau, enables the envisaged micro-mechanic-micro-electronic device integration (Fig. 2). Currently, selected RF components are being realized for demonstration.

Fig. 1: Schematic overview on the multi-physical and level-overlapping design and analysis process in RF-MEMS-based systems.

Fig. 2: Illustration of a hybrid integrated RF circuit based on SiCer substrate combining Si MEMS (top), Ceramics-embedded passives and active CMOS circuits (bottom).

Spokesman: Prof. Dr. rer. nat. habil. Matthias HeinRF and Microwave Research Group

Funding: DFG, FKZ: HE 3642/6-1, SO 1032/1-1, HE 3642/5-1, HO 2284/3-1, MU 3171/1-1


P.O. Box 10 05 65

98684 Ilmenau

Phone +49 3677 69-2831

Fax +49 3677 69-1586

musik@tu-ilmenau�de

http://www.tu-ilmenau.de/musik/

26


FACTS AND FIGURES


BactocatMicro reaction technologies for the discovery of new synthesis strategies by coupling of bacteria-secondary metabolism and nano-catalysis

Bacteria play a key role in industrial biotechnology for the synthesis of pharmaceutical active substances and effect ma-terials. Aim of the project BactoCat (Collaboration of TU Ilme-nau with FSU Jena, iba Heiligenstadt, ICT Pfinzthal, IPHT Jena and HKI Jena) is the screening for new heavy metal-tolerant bacteria which can be used for innovative synthesis strategies combining bacteria biosynthesis and nano-catalysis.

Heavy-metal-resistant Streptomyces strains were isolated from soil from uranium and copper mining areas. They show tolerances against toxic metals such as copper, zinc, nickel and cadmium [1]. The technique of micro segmented flow allows the investigation of the response of bacteria on heavy metal stress. The method was used for the characterization of single bacterial strains (Fig. 1) as well as of complex bacterial communities from soil samples (Fig. 2). Each single microflu-idic test requires only a volume of 0.5 µL. First investigations on the application of chip technology for parallel cultivation of Streptomyces strains in droplets of about 4 nL (Fig. 3) prove the possibility of further miniaturization, which is par-ticular promising for evaluation of soil samples and parallel cultivation of reduced communities and single cells under stochastic confinement conditions. Further investigations address the micro system development and the inclusion of metal nanoparticles in flow synthesis experiments.

Fig. 1: Highly-resolved dose/response function of a Streptoces strain from a mining area cultivated in sequences of micro fluid segments with stepwise varied copper concentration [2]

Fig. 2: Highly-resolved dose/response function of the bacterial communities from two soil samples showing a sharp concentration-related transition between strong and strictly reduced bacterial growth

Fig. 3: Highly reproducible character of mycel-forming bacterial colonies culti-vated in 4-nL-droplets in a chip array (development together with IPHT Jena and Microfluidic Chip Shop Jena)


P.O. Box 10 05 65

98684 Ilmenau

Phone +49 3677 69-3629

michael�koehler@tu-ilmenau�de

http://www.tu-ilmenau.de/mrt/forschung/projekte/

Spokesman: Prof. Dr. rer. nat. habil. Michael KöhlerGroup for Physical Chemistry / Microreaction Technologyhttp://www.tu-ilmenau.de/mrt/

Funding: BMBF, FKZ: 031A161A

[1] Schmidt A. et al: Heavy metal resistance to the extreme: Streptomyces strains from a former uranium mining area. Chemie der Erde 2009, 69, S2, 35-44.

[2] Haferburg G. et al: Arousing sleeping genes: shifts in secondary metabolism of metal tolerant actinobacteria under conditions of heavy metal stress. Biometals 2009, 22, 225-234.

27


FACTS AND FIGURES


AIMS in OPVAnalytik mittels Imaging Methoden und Simulationen in der organi-schen Photovoltaik

Fig. 1: Thermography image of a polymer solar module on glass substrate

Fig. 2: FEM-simulation of the lateral electrical power loss through the ITO-electrode of a polymer solar cell


P.O. Box 10 05 65

98684 Ilmenau

Phone +49 3677 69-3711

harald�hoppe@tu-ilmenau�de

http://www.tu-ilmenau.de/techphys1/

Organic photovoltaics matured rapidly during the last decade and currently exceeded 10% of power conversion efficiency while the device stability is reaching more than 10,000 hours. Both values are sufficient for entering markets with good commercial prospects. Nevertheless a broad commerzialisa-tion did not happen yet, although organic and escpecially polymer photovoltaics has some particular advantages over classical silicon photovoltaics since the photoactive materials are soluble and thus printable roll-to-roll in large scale dimen-sions: The modules are flexible, of light weight, deliverable in many different colors and potentially producible at low cost.The challenges of this production approach are the require-ments that are made to the high speed roll-to-roll production: very thin layers (~100 nm) have to be applied with high lateral and longitudinal precision and all functional layers have to be separated into sub-cells simultaniuosly with the web speed, e.g. via laser ablation, in order to produce solar cell modules.Furthermore and in contrast to classical silicon photovoltaics organic photovoltaics suffer a lot from extrinsic and intrinsic degradation mechanisms between flexible encapsulation due to its relatively weak carbon bondings and heterogen material structure.To support the efforts of commerzialisation, a BMBF-project called "Analytik mittels Imaging Methoden und Simulationen in der OPV - AIMS in OPV" was launched at TU Ilmenau in September 2012. This project addresses on the one hand the detection procedure for quality control of OPV-devices by imaging methods to localize production and degradation defects, which is on the other hand complemented by a full electro-optical modeling of the devices for a better quantita-tive understanding.Exemplarily results of the characterization of the device quality, thermography images of an above-named organic solar module, are shown in figure 1. First results of the full electro-optical modelling are presented in figure 2.

Spokesman: PD Dr. rer. nat. habil. Harald Hoppehttp://www.tu-ilmenau.de/techphys1/team-solution-processed-photovoltaics/

Funding: BMBF, FKZ: 03EK3502

28


FACTS AND FIGURES


XPS-AnalyticsPhotoelectron spectroscopy with high lateral resolution and depth profiling

Spokesman:Prof. Dr. rer. nat. habil. Stefan Krischok http://www.tu-ilmenau.de/techphys1/

Funding: TMBWK, FKZ: 12021-715

Photoelectron spectroscopy is a powerful tool to investigate the chemical composition of surfaces qualitatively and quan-titatively. Moreover, a detailed analysis of the XPS spectra allows to analyse not only the surface stoichiometry but also to obtain valuable information about the chemical environ-ment of the detected element. By other words, the analysis of the valency of the present elements as well as the anlysis of the present functional groups is possible. With the new system the analysis of inhomogenous samp-les is possible, since a lateral resolution of 100 µm can be achieved. In parallel, the new aparatus allows to obtain depth dependent information by subsequently removing material from the sample surface by ion bombardment (sputtering) between consecutive XPS data aquisition runs. Due to a fast sample transfer and the possibility to analyse samples up to 100mm diameter, the system is perfectly suitable to analyze a variaty of samples handled in the technological processes in the IMN MacroNano®.

Photograph of the new analytical system


P.O. Box 10 05 65

98684 Ilmenau

Phone +49 3677 69-3202

stefan�krischok@tu-ilmenau�de

http://www.tu-ilmenau.de/techphys1/

The system is furthermore equipped with a charge neutralizer in order to allow the analysis of insulating samples. The analytical capabilities are further improved by additional analytical options such as mass spectrometry and ultraviolett photoelectron spectroscopy.Typical materials to be investigated in future are compound semiconductors (e.g. III-nitrides and other III-V compounds), oxides, electrodeposited materials, nanoparticles, ionic liquids, layered metal structures and other heterostructures, glasses, polymers and other organic materials, carbon nanos-tructures etc. adressing scientific question in fields such as photovoltaics, thermoelectrics, sensorics, (opto)electronics, energy storage, electrochemistry and fundamental science. In summary the new equipment is a powerful tool, which will improve the analytical capabilities of the IMN MacroNano®and will be usefull for many groups.

29


FACTS AND FIGURES


Deep Reactive Ion Etching tools for micro- and nanostructures

Spokesman:Prof. Dr-Ing. habil. Martin Hoffmann and Prof. Dr.-Ing.habil. Ivo W. Rangelowhttp://www.tu-ilmenau.de/mms (/mnes)

Funding: TMBWK, FKZ: 11039-715

Deep reactive ion etching of silicon is a key technology for three-dimensional functional structures in micro- and nano-technologies.The funding for scientific infrastructure by State of Thuringia gave the chance for strategic improvement of the etching capabilities.This expansion addresses on one hand the highly efficient etching of microstructures with very high quality including the etching of Silicon on Insulator (SOI) substrates and on the other side the ultra-precise etching of nanostructures by using of cryogenic processes. A twin system (figure 1) consisting of a PlasmaPro 100 ESTRELAS for micro-etching and a PlasmaPro 100 Cobra for nano-etching at cryogenic temperatures fulfils these widely diversified requirements. Oxford Instruments Plasma Technology provided both tools.The PlasmaPro 100 ESTRELAS uses a high-density plasma source with inductive excitation. The modern gas, pressure and power control systems enable very fast gas chopping processes for fast and precise deep silicon etching above 14 µm/min. A high frequency source and an additional low frequency source allow the effective control of ion bombard-ment and sample charging.

Thus, an etching of SOI-substrates without notching effects caused by charging is now available (figure 2 left). The side-walls show optical quality (roughness < 20 nm).The PlasmaPro 100 Cobra is equipped with cryogenic subst-rate table for temperatures down to -150 °C. This allows the accurate control of redeposition processes on the sidewalls and thus an effective sidewall protection while etching (figure 2 right). The ultra-wide process-parameter range makes it possible to reduce the etching rate to below 10 nm/min and therefore a precise control of the depth in nanometre range.As a feature for ongoing research on processes especially for nanostructures such as self-masked silicon nano grass the tool uses an optical emission spectrometer (OES). This spec-trometer can monitor the changing chemical composition of the plasma in real time. The aim is to use this information for active process control in each etching cycle.


P.O. Box 10 05 65

98684 Ilmenau

Phone +49 3677 69-2487

martin�hoffmann@tu-ilmenau�de

http://www.tu-ilmenau.de/mms

Fig. 1: Deep silicon etching tools PlasmaPro 100 Estrelas and PlasmaPro 100 Cobra for micro- and nanostructures

Fig. 2: Etching results: SOI etching (left) Nano-etching with low rate (right)

30


FACTS AND FIGURES


DINTOR „Grundlagen der Darstellung und Messung dynamischer Drehmomente“ 2012 - 2014 FKZ: FR 2779/2-1

FUNParty„Funktionelle Nanopartikel-Anordnung durch Entnetzung von dünnen Schichten“2013 - 2016FKZ: SCHA 632/20-1

GRANT I + II„Skalierte Graphen-Nanoribbon-Transistoren für Höchstfre-quenzanwendungen - SPP Graphene“2013 - 2016FKZ: SCHW 729/16-1, PE642/11-1

Ionische Flüssigkeiten „Temperature dependence of the surface electronic struc-ture, solvation properties of simple atoms and ions and irradiation induced degradation of Ionic Liquids studied by electron spectroscopy and density functional theory” 2008 - 2012 FKZ: KR 2228/5-1, KR 2228/5-2

MACRAME„Miniaturiserte aktive Hochfrequenz-Metamaterial- Schaltun-gen“2014- 2017FKZ: HE 3642/8-1

MAXCoat I + II „Synthese und Eigenschaften von MAX-Funktionsschichten“ 2011 - 2015 FKZ: SCHA 632/10-2, SCHA 632/10-3

MOSFETs„Experimentelle und theoretische Untersuchung der Wir-kungsweise von Silizium-Nanodraht-MOSFETs“2012 - 2013FKZ: SCHW 729/10-2

MUSIK - Forschergruppe 1522 „Multiphysikalische Synthese und Integration komplexer Hochfrequenz-Schaltungen“ 2012 - 2015 FKZ: HE 3642/6-1; SO 1032/1-1 TP1; HE 3642/5-1 TP3; HO 2284/3-1 TP6; MU 3171/1-1 TP7

Nanoskalige OFETs „Nanoskalige OFETs für die Anwendung in Schaltkreisen“ 2011 - 2014 FKZ: SCHE 645/9-1, SCHE 645/9-2

Nanostrukturdeposition„Forschung und Entwicklung eines Nanostrukturdepositions-verfahrens“2014 - 2016FKZ: JA 1023/4-1, STA 556/4-1

European Union (EU)

3DNeuroN “Biomimiking the brain - towards 3D neuronal network dynamics” 2012 - 2014 FKZ: 296590

INTASENSE “Integrated air quality sensor for energy efficient enviroment control” 2012 - 2014 FKZ: 285037

NANOHEAT “MultidomaiN plAtform for iNtegrated MOre-tHan-MoorE/Beyond CMOS systems charActerisation & diagnosTics” 2012 - 2015 FKZ: 318625

SNM “Single Nanometer Manufacturing for becond CMOS de-vices” 2014 - 2016 FKZ: 318804

SwIFT “Non-volatile optical Switch combining Integrated Photonics and Fluidics Technology” 2014 - 2016 FKZ: 519643

Federal Funding DFG

AdaScan „Realisierung eines integrierten Mikroauges aus elektrisch verstimmbaren Membran-Mikrolinsen und -prismen sowie variablen Blenden und Filtern“ 2012 - 2014 FKZ: HO 2284/1-2; SI 573/7-2

BactoCat „Basistechnologien Kooperationsprojekt: Neue Syntheseleis-tungen durch Kopplung mikroorganismischer und Metallna-nopartikel-katalysierte Prozesse in der Mikroreaktionstechnik 2012 - 2015 FKZ: 031A161A

DEBRATOR 2 „Wissenschaftliche Grundlagen zur Darstellung und Mes-sung kleiner Drehmomente – Entwicklung einer Drehmo-ment-Normalmesseinrichtung für kleine Drehmomente mit reduzierte Messunsicherheit“ 2012 - 2014 FKZ: TH 845/3-1

DFG-Gerätezentrum „Gerätezentrum Mikro-Nano-Integration“ 2013 - 2016 FKZ: MU 3171/2-1, SCHA 632/19-1, HO 2284/4-1

Scientific ProjectsWissenschaftliche Projekte

31


FACTS AND FIGURES



BalticSea Programm: „Auf - und Ausbau innovativer FuE-Netzwerke mit Partnern in Ostseeanrainerstaaten“Projekt: Innovationsnetzwerk Mikro-Nano-Integration2012 - 2013FKZ: 01DS12024

CarboSens„Verbundprojekt: Integration massengedruckter Carbon Nanotube Sensorelemente in Mikrosysteme - CarboSens - Teilvorhaben: Chemische Sensorik“2010 - 2013FKZ: 16SV5326

iKERSATEC„Innovative keramische Schaltungsplattformen - und techno-logien“2013 - 2016FKZ: 50YB1303

iMUSEUM„Integrierte Multifunktionssysteme für Energiewandlung, Energiespeicherung und Energienutzung durch Multiskalen-materialien“2013 - 2014FKZ: 03DS13009 ISWSensors VIP „Validierung des Innovationspotenzials wissenschaftlicher Forschung Interferometrische Stehende-Wellen-Sensoren“ 2012 - 2015 FKZ:16V0235

KD OptiMi20 „Zweite Phase Kompetenzdreieck: Optische Mikrosysteme - optofluidische und optomechanische Mikrosysteme“ 2011 - 2013 FKZ: 16SV5473

Keramis-GEO „Weltraumtaugliche Technologiedemonstratoren für die In-Orbit-Verfikation auf dem H2SAT - Kommunikationssatelliten zu entwickeln, aufzubauen und zu testen“2011 - 2013 FKZ: 50YB1112 MetaZIK BioLithoMorphie„Assemblierung biologischen Materials mit Hilfe lithographi-scher Methoden zur Konstruktion dreidimensionaler biologi-scher Morphologie, TP: Systeme, Substrate und Sensorik für die BioLithoMorphie“2014 - 2015FKZ: 03Z1M511

µ4CNC„Modulare multifunktionale Vakuum-Mikromessstation nach dem CNC-Prinzip, Mikrotastsysteme zur multifunktionalen Charakterisierung“2014 - 2016FKZ: KF 2731206DB4

Seebeck Gassensoren2014 - 2016FKZ: HI 1800/1-1

SFB 622 NanopositionierungA2: NanomesstechnikA5: Nanopositioniersysteme großer BewegungsbereicheA11: Dynamische Nanopositionierung für kleineBewegungsbereicheA12: Multifunktionale NanoanalytikB2: NanokonstruktionB5: Tribologische EigenschaftenB7: Nanotools für Nanoposionier- und NanomessmaschinenC6: Modularer Entwurf modellbasierter Regelungen2009 – 2013

Stress-OFETs „Hysterese und Reaktionen auf Stress in organischen Feldef-fekt-Bauelementen“ 2010 - 2014 FKZ: SCHE 645/7-1

ThermInO“Tuning of the thermoelectric properties of Inx(M)2-xO3 – nanoparticles”2009 - 2015FKZ: KR 2228/6-1

THz-Emitter„Intensive wellenleitergebundene Terrahertz-Strahlenquelle auf InN-Basis“2010 - 2014FKZ: SCHW 729/13-1

VopSys „Verallgemeinerte optische Abbildungssysteme“ 2012 - 2015 FKZ: SI 573/9-1

Federal Funding (BMBF or BMWT)

1D-SENSE„1D-basierte Sensoren für Gase und Magnetfelder - 1D-SEN-SE, Teilvorhaben: 3D-Silicium-Template für die 1D-Sensorik“2014 - 2016FKZ: 16ES0290

3DNanoDevice „Zentrum für Innovationskompetenz - Nachwuchsgruppe: Drei-Dimensionale Nanostrukturierung zur Realisierung von Hochleistungs-Nano-Bauelementen“ 2012 - 2016 FKZ: 03Z1MN11 AIMS in OPV „Analytik mittels Imaging Methoden und Simulationen in der OPV“ 2012 - 2016 FKZ: 03EK3502

32


FACTS AND FIGURES


Pharm Test „Systementwicklung zur Simulation von Halbwertszeiten von Testsubstanzen/Pharmazeutika in der dreidimensionalen Zellkultur: Entwicklung und Systemintegration von 3D-Zell-kultivierungssystemen in ein modulares, gradientenfähiges Pumpsystem“ 2012 - 2014 FKZ: KF2731202AK0

SADMOX (SAFESENSE) „Sensor technologies for enhanced safety and security of buildings and its occupants - SAFESENSE, Teilvorhaben: Strukturanalytik und Demonstrator an Metalloxiden für die Gasanalyse (SADMOX)“ 2014 - 2017 FKZ: 16ES0226

Sensor Arrays „Multifunktionale Sensorplattform zur Erfassung von bioche-mischen Parametern in den Life Sciences: Entwicklung und Test multifunktionaler Sensor-Arrays auf der Basis von AlGaN/GaN-Sensoren“ 2013 - 2015 FKZ: KF2731204WD3

SINOMICS „Skalenübergreifende Integration von Nanodraht-Heterost-rukturen mit Optischen Mikrosystemen für Innovative Chemi-sche Sensoren Teilprojekt: Freiraumoptische Systemintegrati-on zur Gestaltung des Mikro-Nano-Interfaces für chemische Sensoren auf der Basis von Nanodraht-Heterostrukturen“ 2011 - 2014 FKZ: 16SV5384 WK Basis „Wachstumskern BASIS - BioAnalytics and Surfaces for Integrations in Systems Teilprojekt: Strukturierung und Modifikation von Oberflächen sowie Realisation einer Bio-Mikrosystem-Testumgebung für hydrogelbeschichtete Träge-relemente“ 2011 - 2014 FKZ: 03WKCB01O

ZEKUSE „Extrahierung von Stoffen in einer 3D Zellkultur auf der Basis von MatriGridstrukturen“ 2012 - 2014 FKZ: KF2731203MD2

Nano-III-V-PIN´s„NanO-III-V-PINS´s: Nanoskalige II-V/Silizium Heterostruktu-ren für hocheffiziente Solarzelllen Teilprojekt: Nanoskalige III-V-Strukturen auf Siliziumsubstraten“ 2010 - 2014 FKZ: 03SF0404A

NanoMiFlu „Nanotechnologie basiertes Mikrosystem zum insitu- Fluid-monitoring Teilvorhaben: Mikro-Nano-Interfaces für Hoch-druckküvetten mit IR-Sensorik“ 2011 - 2014 FKZ: 16SV5360

NanoMiPu „Virtuelle Membranaktoren auf Nanostrukturen in Mikro-Pumpen“2010 - 2013 FKZ: 16SV5369

NanoTecLearn „NanoTecLearn - E-Learning für die Aus- und Weiterbildung in der Mikro-Nano-Integration“2014 - 2017 FKZ: 01PD14006

O2-Sens „Niedrigenergie-Sensor zum Nachweis von Sauerstoff in Ver-packungen mittels RFID-O2-SENS Teilvorhaben: Erforschung passiver Sensorkonzepte“ 2011 - 2013 FKZ: 16SV5277

OK - Tech „Das Projekt OK - Tech hat zum Ziel, eine On-Orbit-Verifikati-on an Bord des TET-1-Leo-Satelliten durchzuführen und den Reifegrad der keramischen Mikrowellenschaltungstechnolo-gie für Satellitennutzlasten zu erhöhen“2012 - 2013 FKZ: 50YB1222

OpMihySen „Optische Mikrosysteme für ultrakompakte hyperspektrale Sensorik Teilprojekt: Systemintegration und Anwendung“ 2011 - 2014 FKZ: 16SV5575K

OXIvent „Bedarfsgerechte Sauerstoffabgabe in der klinischen Ventila-tion Teilprojekt: Patientennahe IR-Atemgasanalyse mit opto-fluidischer Messzelle“ 2011 - 2014 FKZ: 16SV5606


33


FACTS AND FIGURES


XPS-Analytik „Photoelektronenspektroskopie mit lateraler Auflösung und Tiefenprofilierung“2012 - 2013 FKZ: 12021-715

Zwanzig20„Unterstützung der Förderinitiative Zwanzig20 des Bundes“2012 - 2013FKZ: 12057-514

Federal Funding DAAD IPID „Autonome Mikrosysteme für die Biosensorik“ 2010 – 2013 DAAD

Industry

Integration Black Silicon AbsorberMicro Hybrid GmbH2014 - 2015

kgeo-adapt2014 - 2015

OSRAM „Fluidic Self-Assembly of Area lighting LED Arrays” 2012 - 2015 FKZ: 7700046871

SONG „Industrieprojekt AZUR Space GmbH” 2013 - 2015

Qualitative Untersuchung des Verhaltens von Ge Substraten „Qualitative Untersuchung des Verhaltens von Ge Substraten“ 2012 - 2013 AZUR SPACE

VIA electronic GmbH2014

Zeiss „Industrieprojekt Carl Zeiss Jena GmbH“ 2013 - 2014

Federal Funding Thuringia

EU Broker“European Micro Nano Broker Platfrom”2010 - 2013FKZ: TNA VI-1/2010

FGR OptiSolar„Steigerung von Zuverlässigkeit und Wirkungsgrad mittels Optimierung kritischer Grenzflächen in Silizium-Solarzellen” 2013 - 2014FKZ: 2012 FGR 0231

Green-Photonics“OptiMi 2020 - Graduate Research School ‘Green Photon-ics’”2011 - 2013FKZ: B514-10062

NanoZellkulturen „Biotechnisches Multiskalenengineering am Beispiel der Mi-kroreaktiorenentwicklung zur Modellierung der NanoNische für spezialisierte Zellkultursysteme“ 2010 - 2013 FKZ: B714-09064

NanoBatt „Steigerung der Energie- und Materialeffizienz elektrochemi-scher Energiespeicher durch Nanostrukturierung von Werk-stoffen und Oberflächen“ 2012 - 2013 TNA VII-1/2012

OMITECGraduate Research School - Optical Microsystem Technolo-gies “ProExzellenz”2009 - 2013FKZ: PE 104-1-1

Siliziumtiefenätzanlage „Förderung der Infrastruktur in Forschung und Entwicklung ‚Siliziumtiefenätzanlage‘“ 2012 - 2014 FKZ: 11039-715

SITAW „Neuartige 3D-Taster und Wägezellen auf der Basis von Silizium-Messchips“ 2012 - 2014 FKZ: 2012 FE 9019

USENEMS„Ultrasensitive Materialien für Nanoelektromechanische Sys-teme“2010 – 2013KKZ: B714-10048


34


FACTS AND FIGURES



Trusts

Jose Carreras „Modellierung der hämatopoetischen Stammzellnische in vitro: 3D-Kultur, Kokultur und verringerte Sauerstoffkonzen-tration als Parameter zur Erhöhung der Stammzellprolifera-tion“ 2014 - 2016 FKZ: DJCLS R 13/18 Jose Carreras-Stiftung

Carl-Zeiss „Untersuchung von Zellen mit neuartiger hybrider funktio-nalisierter Biosensorik in drei Dimensionen“ 2013 - 2014 FKZ: 0563-2.8/399/1 Carl-Zeiss-Stiftung

SACCA „System for Automated Cell Cultivation and Analysis“ 2014 - 2017 FKZ: 0563-2.8/416/3 Carl-Zeiss-Stiftung

35


FACTS AND FIGURES


Project Statistics 2010 - 2014Projektstatistiken 2010 - 2014

Die Drittmitteleinnahmen aus den wissenschaftlichen Projekten haben sich in den vergangenen fünf Jahren weiterhin positiv entwickelt� Die gesamte Fördersumme konnte von 6,5 Mio� EUR in 2010 auf rund 9,1 Mio� EUR erhöht werden� Wichtigste Fördermittelgeber sind der Bund mit mehr als 26,8 Mio� EUR (Anteil 58%), das Land Thüringen mit mehr als 10,6 Mio� EUR (Anteil rund 23 %) und die Deutsche Forschungsgemeinschaft mit mehr als 3,7 Mio� EUR (Anteil rund 8 %)�

Auf der Ausgabenseite dominieren die Personalkosten für wissenschaftliche Mitarbeiter, technisches Personal und studentische Hilfskräfte. Die Anzahl der durch Drittmittel finanzierten wissenschaftlichen Mitarbeiter konnte von 68 (2010) auf 72 (2014) erhöht werden� Ferner werden derzeit 9 Techniker und Laboranten aus Drittmitteln bezahlt (Vollzeitäquivalente)� Für investive Maßnahmen konnten mehr als 11,8 Mio� EUR aus Drittmitteln bereitgestellt werden� Dies resultiert in einem umfangreichen und modern ausgestatteten Technologiepark, der in den Laboren des ZMN verfügbar ist�

Fig. 1: The revenues from research projects during the last five years from EUR 6.5 mil. in 2010 up to EUR 9.1 mil. in 2014

Fig. 2: Most important are the revenues from federal funding (BMBF EUR > 26.8 mil., DFG EUR > 3.7 mil., EU EUR > 2.7 mil.) and Thuringia (EUR > 10,6 mil�)

Fig. 3: The largest positions are assigned to scientific staff (EUR > 22.5 mil.), investments (EUR > 11.8 mil.) and material expenses (EUR > 2.7 mil.)

Fig. 4: The scientists headcount in projects increased from 68 to 72 during the last five years

Revenues in research projects Funding sources of research projects

Spending of Revenues Employees in projects

€6.483.283

€9.855.575

€11.985.450

€9.243.269 €9.187.279

0

2000000

4000000

6000000

8000000

10000000

12000000

14000000

2010 2011 2012 2013 2014

Federal Funding (DFG)8% Trusts

2%

Foreign Funding0%

Federal Funding (BMBF or BMWI)

57%

Thuringia23%

Industry3%

FhG0%

European Union6%

Federal Funding(DAAD)

1 %

Scientific Staff 48 %Technical Staff 4%

Students 1 %

Investments 25 %

Material Expenses6% Subcontracts 7%

Others 9 %

10 10 9 12 9

68 6973

84

72

0

10

20

30

40

50

60

70

80

90

2010 2011 2012 2013 2014Members of Technical Staff (left columns) Scientists (right columns)

36


FACTS AND FIGURES


search, ZMN’s infrastructure is also offered to interested partners, such as companies or research institutions.

Process classes

• Biological and chemical analytics• Material- and nano-analytics• Preparation for analytics• Physical-optical analytics • Electrical characterization• Lithography• Chemical deposition• Physical deposition• Thermal treatment• Wet-chemical processes• Plasma based etching• Microsystems Assembly Technologies• LTCC- and Thick Film Hybrid Processing• Laser- and precision machining• Printed circuit board processing• Thermomechanical processing• Biological-chemical methods• Processing of polymer

The ZMN is an interdisciplinary infrastructural unit hosting the equipment, clean rooms and technologies of the Insti-tute of Micro- and Nanotechnologies. Doors of ZMN were opened to the entire university by converting the status to an operational unit of Technische Universität Ilmenau which was accompanied by the founding of the interdisciplinary Institute of Micro- and Nanotechnologies MacroNano®.

The ZMN made a very successful development with regard to the installed technological and analytical sci-entific equipment and the management of its operation over the last years. Today, one can find technologies for structuring, deposition and surface treatment for a broad material spectrum (e.g. silicon, group III based semicon-ductors, metals, oxides, glasses, ceramics and polymers) and high-end analytical instruments with a resolution down to the scale of single atoms. In 2013, a forward-looking expansion as a Core-Facility “Micro-Nano-Inte-“Micro-Nano-Inte-Micro-Nano-Inte-gration“ with better access for external scientists started.

The success story of the ZMN is closely linked to the research efforts of the IMN MacroNano® groups which define the scientific profile as well as the future strategy. Research without barriers is promoted by the spatial closeness of and the ease of access to different technologies within the labs and cleanrooms in the Feynmanbau and Meitnerbau. In addition to the possibilities of joint and contract re-

Center of Micro- and NanotechnologiesZentrum für Mikro- und Nanotechnologien (ZMN)

Feynmanbau (left) and Meitnerbau (right), the home of the ZMN

Office area in the Feynmanbau

The Center of Micro- and Nanotechnologies (ZMN) acts as an operation unit of the Technische Universität Ilmenau and forms the technological platform for basic and applied research in the field of micro- and nanotechnologies. Overall, the center has about 2,000 m² of laboratory space available, including more than 1,200 m² in clean rooms of different classes and special labs for handling of biological samples or for the installation of high-precision measurement and manipulation machines�

Das Zentrum für Mikro- und Nanotechnologien (ZMN) ist eine Betriebseinheit der TU Ilmenau� Es steht als Technologie-Platt-form sowohl für die grundlagenorientierte, als auch für die angewandte Forschung im Bereich der Mikro- und Nanosysteme sowie der Materialwissenschaften zur Verfügung� Dazu gehören Basistechnologien zur Beschichtung, Strukturierung und Oberflächenbearbeitung von Silizium, Gruppe III-basierten Halbleitern, Metallen, Oxiden, Gläsern, Keramiken für Hybridtech-niken und von leitfähigen Polymeren für Solarzellen und druckbare Elektronik� Eine leistungsstarke Analytik bis in die atoma-re Größenordnung rundet die wissenschaftliche Ausstattung ab�

37


FACTS AND FIGURES


• Fourier-transformed infrared-spectrometer with ad-ditional bolometer can detect infrared active surface states in transmission and reflection mode. With its additional UHV-chamber it is possible to investigate surfaces under ultra high vacuum conditions. (Bruker)

• Scanning tunneling microscope STM operating in UHV and performing surface scans with atomic resolution. 150 Aarhus (SPECS)

• X-ray and Ultraviolet Photoelectron Spectroscopy (XPS, UPS) system including sputter depth profiling and charge compensation for chemical and elemental com-position analyses down to 0.1 at. %, XPS mapping with 100 µm lateral resolution and characterization of work function and electronic surface properties including Ar+ and O- ion induced Secondary Ion Mass Spectro-metry for qualitative elemental depth profiling of thin films with a sensitivity below 0.1 at. %. Sage (SPECS)

New equipment in 2013 / 2014:

Etching technologies

• Deep Reactive Ion Etching system with ICP source for microstructures with high aspect ratios. ESTRELAS (Oxford Instruments Plasma Technology)

• Deep Reactive Ion Etching system with ICP source and cryogenic chuck for nanoscale etching with high aspect ratios. COBRA (Oxford Instruments Plasma Technology)

Lithography

• Soft Nano Imprint Lithography Tool for substrate sizes up to 200 mm. GD-N-03 (demonstration tool

GDnano/5microns)

Analytics

• Laser scanning microscope for fast profilometry with ultra high resolution. LEXT 4100 (Olympus)

• 4-Probe-scanning tunneling microscope to investigate the electronic properties of nanowires under different potentials and at very low temperatures. Additionally a SEM is applied to the system for the positioning of the four different tungsten tips to the specimen. (mProbes)


Deep Reactive Ion Etching systems ESTRELAS and COBRA X-ray and Ultraviolet Photoelectron Spectroscopy system Sage

38


FACTS AND FIGURES


Metal organic chemical vapor deposition system AIX200

Thin film deposition

• Metal organic chemical vapor deposition with twin reactor for growing of III-V-semiconductors and silicon layers in two different reactors. The first reactor is used for standard 1“ x 1“-samples. The second reactor can grow layers on rotating 2“-wafers. A genius reactor-to-UHV-system is installed for transfering freshly grown samples without air exposure to various surface investi-gation tools. MOCVD AIX200 (Aixtron)

• Metal organic chemical vapor deposition single reactor used for MOCVD-processes with very high temperatures on 1“ x 1“-samples can be performed. In-situ investigation of grown surfaces can be done by reflective-anisotropy-spectroscopy (RAS). Direct transfer of grown samples to UHV is possible. MOCVD AIX200 (Aixtron)

• High Temperature Vacuum Tube Furnace for annealing, diffusion and sintering up to 1200 °C and for the growth of semiconductor nanostructures using chemical vapor deposition. BTF-1200C-III (Anhui BEQ Equipment Tech-nology)

Polymer processing

• Laser ablation system with three different wavelengths (1064 nm, 532 nm, 355 nm) for structuring of mo-nolithic solar modules based on solution-processed electrodes and semiconductors

• Slot-die coating system for sheet-to-sheet application for highly precise solution-based deposition of functio-nal layers for solar cells

Ongoing acquisitions (to be available during 2015)

• Pico second laser center for ceramic based systems


Contact:

Dr. Arne Albrecht

Gustav-Kirchhoff-Straße 7

98693 Ilmenau

Phone +49 3677 69-3426

arne�albrecht@tu-ilmenau�de

www.macronano.de

Nature uses only the longest threads to weave her patterns, so that each small piece of her fabric

reveals the organization of the entire tapestry�

Richard P� Feynman

Members of the Institute

Advanced Electromagnetics ��42Automotive Engineering ��43Biomechatronics ��44Biomedical Engineering ��45Biosignal Processing ��46Chemistry �� 47Electrochemistry and Electroplating��48Electronic circuits and Systems ��49Electronic Measurement Research Lab ��50Electronics Technology �� 51Electrothermal Energy Conversion ��52Engineering Design ��53Experimental Physics I ��54Experimental Physics II ��55Inorganic-Nonmetallic Materials ��56Machine Elements ��57Materials for Electronics and Electrical Engineering ��58Mechatronics ��59Metallic Materials and Composites ��60Micro- and Nanoelectronic Systems �� 61Micromechanical Systems ��62Nano-Biosystems Technology ��63Nanotechnology ��64Optical Engineering ��65Optical Design, Simulation and Modelling of Optical Systems ��66Photovoltaics ��67Physical Chemistry / Microreaction Technology ��68Plastics Technology ��69Precision Engineering ��70Precision Metrology �� 71Process Metrology ��72Production Technology ��73RF and Microwave Research Lab �� 74Solid State Electronics ��75Surface Physics of Functional Nanostructures �� 76System Analysis ��77Technical Physics I /Surface Physics ��78Technical Physics II / Polymer Physics ��79Theoretical Physics I ��80Theoretical Physics II / Computational Physics ��81Three-Dimensional Nanostructuring ��82

41

42

Biannual Report 2013 / 2014

MEMBERS OF THE INSTITUTE

Internet

Research Topics

Contact

EducationThe group provides lectures in theory and application of the electromagnetic field in the academic basic education of the BS degree courses. The courses of the BS education, as well as the main course “General and Theoretical Elec-trical Engineering“ of the MSc degree courses, aim at an enhancement of fundamental knowledge with the intenti-on that students are well-prepared for a quick and success-ful transition into positions of their further career. For this, courses in the specialization phase introduce topics such as electromagnetic CAD, numerical computation of electroma-gnetic fields, basics of modeling and simulation, optimiza-tion, non-linear systems, and superconductive microelectro-nics. The training of skills and abilities for scientific work in electrical engineering, as well as for solving interdisciplinary problems, completes this educational phase. The final phase is dedicated to the training of research work both in pro-jects and teams. For this, the students are integrated, at an early stage, into research groups and thus become familiar with topics of fundamental research and R&D cooperation with industrial partners. A special activity is devoted to the academic training of PhD students in a Research Training Group. Furthermore, the group is as a partner within the “German Engineering Faculty MEI-TU-Ilmenau“ and is active in the scientific management of an academic network with several universities from South-Eastern Europe. For school classes, experimental courses are provided.

GroupThe group of Advanced Electromagnetics has a focus on theory and computation of electromagnetic fields as well as simulation of heterogeneous systems with the aim of utili-sing physical principles in innovative applications. Currently, emphasis is put on various fields of electromagnetic sensor technology.

ResearchResearch in the group is devoted to such physical relation-ships and mathematical approaches which can be utilised suitably for solving practical problems and tasks in the pro-fessional practice of electrical engineering. This naturally implies a close connection to applications and implemen-tations. For a better practical utilization of the theoretical findings, the group operates four research laboratories. In particular, experimental investigations are carried out in the cryoelectronics laboratory with measurement equip-ment for superconductive sensors and circuits, in the ma-gnetics laboratory for material characterization, the Lorentz force laboratory of a DFG Research Training Group, and in the lab for capacitive sensor systems. In addition, equip-ment for signal characterization is available. The infrastruc-ture for research and education also includes a computer pool for field computation, for simulation, and design of sensor structures and microelectronic circuits. The group maintains national and international research relationships .

Advanced ElectromagneticsTheoretische Elektrotechnik

• Ultra-sensitive superconductive sensors with quantum accuracy

• Single-flux-quantumelectroniccircuits

• Lorentz-force and eddy-current techniques for material characterization

• Solution of inverse problems in electromagnetics

• Capacitive sensors

• Analysis of non-linear systems

Research Topics

Fig� 2: Fodel parallel lines� Line width/space 30 μm/30 μm (l� – green/REM;r.–cofired/REM)Univ.-Prof. Dr.-Ing. habil.

Hannes Töpfer

Telefon +49 3677 69-2630

Telefax +49 3677 69-1152

hannes�toepfer@tu-ilmenau�de

Fakultät für Elektrotechnik und

Informationstechnik

TU Ilmenau

Helmholtzplatz 2

Helmholtzbau, Raum 2545

98693 Ilmenau

Contact

www�tu-ilmenau�de/it-tet

Research Topics

Contact

43



Internet

Contact

Research Topics

Special equipment• Test Center for Chassis and Brake Engineering• Drivetrain Test Field (Axle Distortion Test Field)• Servohydraulic Test Stand (Hydropulser) • Component/actuator test stands (chassis):• ABS/ESP control equipment • Steering test stand • Life cycle tests, sealing • Hardware in the loop (HiL) • Coating compression and shearing test rig • Brake systems • Pedal operating system (brake robot) • Flow channel • Tyre test equipment • PIV system • 3-D laser scanning vibrometer• Digital high-speed camera • Real-time systems for measuring and controlling, hard-

ware in the loop• Signal recording • Measuring devices for vehicle dynamics • Vibration and acoustic measuring systems • Infrared camera • Engine tester• Axle measuring system

Services offered• Brake tests: The performance of wheel brakes, brake

noise studies, the fine dust emission of brake systems, vibration and dynamic properties of brake components, tribology and material studies

• Performance of transmission and drivetrain elements• Noise emission from drive systems• Studies on vehicle dynamics• Theoretical analysis: FEM structural analysis, MKS sys-

tem analysis and system simulation (brake systems, hy-draulic/mechatronic systems and drivetrain)

• Virtual reality studies• Consulting• CFD calculations: analysing particle flows• Experimental analysis of flow processes in vehicle sys-

tems• Designing alternative powertrains • Development design, production and installation of

component test rigs and special test vehicles • Development of sensors and measuring systems

Automotive EngineeringKraftfahrzeugtechnik

Fig� 2: Fodel parallel lines� Line width/space 30 μm/30 μm (l� – green/REM;r.–cofired/REM)Univ.-Prof. Dr.-Ing.

Klaus Augsburg

Telefon +49 3677 69-3842

Telefax +49 3677 69-3840

klaus�augsburg@tu-ilmenau�de

Fakultät für Maschinenbau

TU Ilmenau

Gustav-Kirchhoff-Platz 2

Newtonbau, Raum 2220

98693 Ilmenau

Contact

Research Topics

Internet www�tu-ilmenau�de/kft

• Brakeandchassisengineering(ExperimentsandAnalysis)

• Alternative powertrains

• The human-machine interface in the vehicle

• Active safety optimization through progress in driver assistance systems

• Studyingparticleflows

• Optimizationofpowertrainefficiency

• Development design, engineering, production and functional testing of stationary and mobile measuring and

test equipment

Contact

Research Topics

44



Internet

Research Topics

Contact

nisms is considered. Great interest is directed towards ki-nematics and dynamics of animals and human beings, the latter as well as an object of human medicine. Their locomo-tion including the use of the trunk, the gripping, and mani-pulation is studied with focus on prevention, diagnostics, and therapy, as well as an example of biological inspiration for adaptive mechanisms in the field of robotics. Robotic strategies are used for e.g. touristic and senior assistance systems with a focus on human-machine-interfaces.

EducationExpertise for research and teaching in cooperation with other groups at the TU Ilmenau and external specialists:• Basic medical education (anatomy and physiology)• Bionics of construction and material, with a focus on

micro systems and robots• Compliant, biologically inspired mechanisms• Ecological Models / environment analytics • Ergonomic design of Human-Machine-Interfaces (HMI)• Mechatronics for Bio-Medical Engineering • Robotics• Technical Biology• BioMOEMS• Human Serving Systems

GroupThe group of Biomechatronics was founded in 2002 as the first chair of biomechatronics in Germany and is still the only one. Biomechatronics is the development and improvement of mechatronic systems under support of application of bio-medical knowledge. On one hand specific mechatronic pro-ducts and methods have to be adapted to applications for, on and in biological systems and human beings, focussing on their demands – mechatronics for Biomedical Enginee-ring. On the other hand mechatronic design is “biologically inspired”. This process is based on principles of biomimeti-cally oriented methods of engineering (“Technical Biology” and “Bionics”). In conclusion – biomechatronics is not an opposing strategy to existing high technology; it comple-ments and expands the method repertoire of engineering sciences.

ResearchBioMEMS housing cell cultures in micro systems is an expan-ding field of research. Analysis of the human auditive system with focus on prevention of hearing loss is a biomedical core theme.The dominating research topic is the analysis of living and the design of technical motion systems, in which the size spectrum of biological paragons from small to large orga-

BiomechatronicsBiomechatronik

• Biocompatible design

• Bionics focussed on microsystems:

Actuators - Sensors incl� adaptorics - Material

• BioMOEMS

• Cellhandlinginmicrofluidicsystems

• Human Serving Systems

• Mechatronicsinbiomedicalengineering(Bio-MEMS):

Prevention, diagnostics, therapy, rehabilitation

Assistance systems for special groups of users with restricted mobility, e�g� elderly and handicapped people

• Robotics: non-conventional motion systems

Univ.-Prof. Dipl.-Ing. Dr. med. habil.

Hartmut Witte

Telefon +49 3677 69-2456

Telefax +49 3677 69-1280

hartmut�witte@tu-ilmenau�de


TU Ilmenau

Max-Planck-Ring 12

Haus F, Raum 3190

98693 Ilmenau

www�tu-ilmenau�de/biomechatronik

45



Internet

Contact

Research Topics

Univ.-Prof. Dr.-Ing. habil.

Jens Haueisen

Telefon +49 3677 69-2860

Telefax +49 3677 69-1311

jens�haueisen@tu-ilmenau�de

Fakultät für Informatik und

Automatisierung

TU Ilmenau


Bionikgebäude, Raum 112

98693 Ilmenau

Biomedical EngineeringBiomedizinische Technik

www�tu-ilmenau�de/bmti

• Medical technology for ophthalmology

Technology, signal and image processing for fundus imaging, microcirculation diagnostics

and retinal vessel analysis

Metabolic mapping of the retina

Neuro-ophthalmology

• Biomedical measurement and stimulation technologies

• Biomedical data analysis, modeling and inverse methods

Analysis, forward and inverse modeling of bioelectric and biomagnetic data, Investigation of active and pas-

sivebioelectricandbiomagneticphenomena,Numericalcomputationofbioelectricandbiomagneticfields

• Medical imaging and radiological equipment

• Magnetic nanoparticles for biomedical applications

GroupThe Technische Universität Ilmenau has a long and successful tradition in the field of Biomedical Enginee-ring. The Institute of Electromedical and Radiological Engineering was established in 1953 and introduced the first University education program of Biomedical Engineering in Europe. Today, the Institute of Biomedical Engineering and Informatics offers a Bachelor and Master Degree program in Biomedical Engineering, as well as a comprehensive PhD program.

ResearchThe group has extensive experience in development of dry biomedical electrodes and medical electronics. In combi-nation these technologies allow for multichannel recording of bioelectric signals without the need for application of electrode pastes and thus enabling instantaneous measure-ments. We develop algorithms for biomedical signal analy-sis, including on-line signal processing for brain-computer-interfaces. Our technologies enable the decomposition of very complex, multidimensional data for artifact detection, sparse signal representation and parameterization of multi-variate data in neuroscience.

We develop imaging technologies for magnetic nano-particles, which enable the quantitative determination of the distribution of the particles in-vivo from magnetic measurements. Targeted structures can also be localized with the technology. The technology enables promising applications in the diagnosis and monitoring of different di-seases, e.g. cancer.High resolution electromagnetic finite element modeling for neuroscientific applications is another research topic. From an electro- and/or magnetoencephalogram of a patient the electric brain activity is reconstructed on the basis of such models. This technique can be used to decompose spatio-temporal brain activity patterns, localize brain activity and discover connectivity networks. Furthermore, magnetic na-noparticles for biomedical and technical applications are prepared in the group. Our focus is on optimization of magnetic properties for application of the particles in ma-gnetic hyperthermia as minimal-invasiv tumor therapy and magnetic drug targeting.

EducationThe group provides courses in the fields of (selection): • Biomedical Measurement and Instrumentation • Bioelectromagnetism• Radiological equipment and radiation protection• Imaging systems and processing in medicine

46



Internet

Research Topics

Contact

New methods are developed for decomposition and/or se-paration in multimodal (EEG, ECG, EMG, EOG, breathing, video, skin conductance, temperature) and multidimensi-onal signals in time-frequency-space-shift. Innovative ap-proaches for diagnosis and therapy by neuro-implants are developed (cochlea implant, new audiology technologies). New techniques for process modelling in information sys-tems are designed.

EducationOur students receive a broad basic education in enginee-ring and natural sciences, anatomy, physiology and biome-dical engineering. Following this, the students spezialize, in the Masters Program, in one (or more) of five directions: ophthalmology, radiology, assist systems, biomagnetism, electrical devices. The study time is strictly connected to practical work in the 7th semester as well as to laboratory lectures. Students optionally take part in research projects, where they can obtain knowledge and experience in com-plex problems over an extended period of time.

GroupThe group of Biosignal Processing deals with research and development of medical sensors and electronics, develops new biosignal and image processing methods and tools for process modelling in medical information systems for more than 20 years. It is a member of the Institute for Biomedi-cal Engineering and Informatics (BMTI) and of the Institute for Micro- and Nano-technology (IMN) at the Technische Universität Ilmenau. In numerous research projects it coo-perates with experts across technological and methodical borders in micro-technology, integrated electronics, biome-chanics, nanobiology, neurology, cardiology, ophthalmo-logy and audiology. The results of this research and deve-lopment are applied in industry for biomedical engineering, automotive and media technology.

ResearchEvery link of the measurement chain is a focus of our re-search and development: New energy-autarkic implanta-ble sensors are developed for contactless measurement of pressure (eye, heart), for optical non-invasive measurement (fetal Spo2), for wearable electrodes and capacitive sensors (EKG/HRV, EMG, Breathing). New electronic devices are de-veloped for medical instrumentation and amplification with extremely high input impedance, full-band amplifiers, and very fast signal and image processing (CMOS/FPGA, DSP).

Biosignal ProcessingBiosignalverarbeitung

• Newmethodsofdynamicspace-time-frequencyinmedicalengineering(multidimensionalsignals)

• Biosignalprocessing(ECG,EEG,electromyography-EMG)inmedicalmetrology

• Clinical information systems and quality assurance

• Extremelyrapidimageprocessing(CMOSsensors,FPGAporting)

• Objective diagnostics of psychical and neurological diseases

• Contact-less energy-autarkic implantable or wearable sensors

• Medical electronics for extremely high input impedance, capacitive sensing

• MEMS for in-vitro measurement in 3D

• 3D-image processing with high accuracy and extreme short time


Peter Husar

Telefon +49 3677 69-2863

Telefax +49 3677 69-1311

gabi�hey@tu-ilmenau�de


Automatisierung

TU Ilmenau


Bionikgebäude, Raum 108

98693 Ilmenau

www�tu-ilmenau�de/bsv

47



Internet

Contact

Research Topics

controlled way for the modification of the electrochemical properties of CNT and fullerenes based on the type and the degree of their functionalization. To accomplish the aim of the research work, carbon nano-materials with better designed parameters are produced, functionalized and used further for the construction of new devices.

Services offered• Production of carbon nano structures and derivatives• Electrochemical explorations• Chemical analytics by means of AAS, HPLC, GC/MS,

MALDI-TOF, IR, Raman, NMR• MALDI-TOF analysis of macromolecular substances

(protein analysis)• Synthesis chemistry

Special equipment• Electrochemistry (cyclic voltammetry, electrochemical

impedance spectroscopy)• Fullerene and nano tube generators• MALDI-TOF: Measurement of MALDI-TOF spectra of or-

ganic and inorganic substances• AAS, HPLC, GC-MS (gas chromatograph mass spectro-

meter), IR, Raman, NMR

Carbon nanotubes (CNTs) are the interesting, new members of the carbon family, offering unique mechanical and elec-tronic properties combined with chemical stability. Since their discovery, much experimental and theoretical research has been directed toward their production, purification, mechanical and electronic properties, and electrical con-ductivity. Considering the importance of CNTs in the fields of nanoscience and nanotechnology, our research interest is focused on the study of CNT synthesis and growth me-chanisms upon thermal chemical vapour deposition, and their electrochemical properties. The functionalization of CNTs, through a chemical attachment of either molecules or functional groups to their sidewalls, is an effective way to improve their solubility and to enhance their physical pro-perties that make them of potentially useful for technologi-cal applications ranging from nanoelectronics, sensors and electrochemical devices to composite materials.The group of chemistry, in collaboration with other acade-mic and industrial partners, is involved in production of new carbon compounds and nanomaterials via functionalization of either CNTs (single- and multi-walled) or fullerenes and their potential application in different fields. The scientific goal, is to gain a better understanding of the dependence of the chemical properties of the carbon ma-terials on the extent and the type of functionalization. Spe-cifically, the purpose of our research work is to establish a

ChemistryChemie

apl. Prof. Dr. rer. nat. habil.

Uwe Ritter

Telefon +49 3677 69-3603

Telefax +49 3677 69-3605

uwe�ritter@tu-ilmenau�de

Fakultät für Mathematik und

Naturwissenschaften

TU Ilmenau

Weimarer Straße 25

Curiebau, Raum 208

98693 Ilmenau

www�tu-ilmenau�de/chemie

•Fullerenesandcarbon-nanotubes

Production of fullerenes and carbon nano tubes, studies on their formation

Preparation of catalysts for production of aligned carbon nanotubes

Exploration of colloidal fullerene solutions for medical applications

Polymerisation of fullerenes for organic photovoltaics

•Electrochemistry

Preparation and analysis of fullerene derivatives

Analysis of formation and degradation mechanisms of fullerene derivates

Aligned carbon nanotubes as sensor materials

Electrochemical impedance measurements for detection of biomolecules

•Gassensorsandgasanalyticstocharacterisevolatileorganiccompounds

48



Internet

Research Topics

Contact

Research Topics

Special equipment• Chemical and electrochemical measuring techniques

(e.g. potentiostats, impedance analyzers, quartz

crystal microbalance, ion chromatographs, HPLC/MS)

• Lab scale plating line

• Layer characterization (e.g. optical microscopy, XRF,

internal stress, micro hardness, wear resistance)

• Corrosion test cabinet

• Particle characterization (zetasizer, acoustosizer)

• Gloveboxes with integrated electrochemical measu-

ring facilities

• Vibrating sample magnetometer

• Multi-channel battery tester

• Scanning probe microscope in glovebox

Services offered

• Evaluation and optimization of electrochemical pro-

cesses

• Characterization of layers (e.g. thickness, compositi-

on, hardness, wear resistance, corrosion behavior)

• Particle characterization (size, zeta potential)

• Characterization of batteries, fuel cells and electroly-

sers

• Electrochemical characterizations and preparations

in inert gas atmosphere (argon filled glove box,

1 ppm O2, 1 ppm H2O)

Electrochemistry and ElectroplatingElektrochemie und Galvanotechnik

•Fundamentalandappliedelectrochemistry

•Electrochemicalpreparationandcharacterizationoffunctionalcoatingswithtailoredproperties

•Electrochemicalprocesstechnology(e.g.insitumonitoringofprocessparameters,novelplatingtechnolo-

gies)

•Electrochemicalstorageandconversionofenergy(batteries,fuelcells,electrolyzers)

•Ionicliquidsasnovelreactivemediaforelectrochemicalprocesses

•Numericalsimulationofelectrochemicalprocesses

•Electrochemicalsensors

•Magneto-electrochemistry

Univ.-Prof. Dr. rer. nat. habil.

Andreas Bund

Telefon +49 3677 69-3107

Telefax +49 3677 69-3104

andreas�bund@tu-ilmenau�de

Fakultät für Elektrotechnik

und Informationstechnik

TU Ilmenau


Arrheniusbau, Raum 208

98693 Ilmenau

www�tu-ilmenau�de/wt-ecg

Scanning electron micrograph of an electroplated aluminum layer. Deposition was performed from an ionic liquid

Scanning electron micrograph of a NiP-SiC composite layer

Numerical simulation of the potential and current distribution in a Hull cell with poor (left) and good (right) throwing power of the electrolyte

49



Internet

Contact

Research Topics

Electronic circuits and SystemsElektronische Schaltungen und Systeme

•MultiphysicalRF-Systemdesign

•Integratedultra-lowpowerandhigh-speedcircuitdesign

•ElectronicDesignAutomation

GroupThe group of “Electronic Circuits and Systems” is prima-rily engaged in the design of technical systems in the field of information and communication technologies. For this purpose on the one hand fundamentals and sophisticated knowledge of digital and analog circuit design are impar-ted, which are necessary skills for every electronic design engineer. On the other hand the group offers capabilities to handle the complex design flow of integrated electronic sys-tems starting from the system specification to the finalized system. Thereby, the main focus is on design methodology, EDA (Electronic Design Automation) together with current and future design tools and there basic algorithmic back-ground as well as questions of tool usage.ResearchOur research activities are focused on design of integrated, heterogeneous systems consisting of micromechanical and microelectronic high-frequency components. The combi-nation of mechanical and electronic world allows greater functionality while reducing area and power consumption. Currently, analog front ends for LTE and mixed-signal UHF RF-ID applications are designed. For this purpose, new tech-nologies and structures (e.g. active MEMS filter) are used for implementation of known functions. In the UHF RF-ID application (868 MHz) a power consumption of < 1 µW for the entire system is strived.

Another area of interest is proved by requirements of lar-ge data rates in the information technology and consumer electronics. In such applications feedback structures are used most frequently. Particularly in microelectronics, these circuits must meet specific criteria for stability, which can be efficiently addressed only with the help of computer-aided design tools. Therefore, the group of Electronic Circuits and Systems develops algorithms for automated calculation of broadband compensation networks.EducationThe group of “Electronic Circuits and Systems” offers basic lectures for design and analysis of analog as well as digital circuits. For graduate students there are lectures for design of integrated systems, ASIC and FPGA design, programming and technologies of microcontrollers and analog CMOS cir-cuit design. In addition for practical education the group offers a workshop to design a complete analog/mixed signal chip from the idea to the physical realization (layout).Students can gain knowledge and skills in circuit and system design for analog and digital applications, including state-of-the-art industrial tools (e.g. Cadence Virtuoso, Synopsys and Analog Insydes). Students of electrical engineering and other disciplines (e.g. biomedical technology, engineering, computer science, technical physics and mechatronics) can participate in the events.

Univ.-Prof. Dr.-Ing.

Ralf Sommer

Telefon +49 3677 69-2624

Telefax +49 3677 69-1163

ralf�sommer@tu-ilmenau�de



TU Ilmenau

Helmholtzplatz 2


98693 Ilmenau

50



Internet

Research Topics

Contact

Research

Communications, RF engineering, signal processing, and electronic measurement engineering are very distinct dis-ciplines. While their respective methods and applications appear to be quite different, they share common problems in measurement data acquisition, sensor interface design, signal processing, parameter identification, data analysis and information extraction. The Electronic Measurement Research Laboratory is currently conducting several research projects that lie in the crossroad of these disciplines. The main goal is to apply advanced digital signal processing and RF circuit design methods for solving leading edge measure-ment problems in mobile radio and RF sensing.

Education

The Electronic Measurement Research Lab offers undergra-duate and graduate courses aimed at a highly qualitative education of the students. The spectrum comprises courses and labs on fundamental and specific topics of electric and electronic measurements as well as advanced approaches to process measurement data.

Electronic Measurement Research LabElektronische Messtechnik

• Measurement and modelling of mobile radio channels

• Directional resolved signal processing for mobile radio systems with multiple antennas on both sides of the

transmission link

• Link- and system-level simulation of mobile radiotelephone systems with adaptive antennae

• Ultra-broadband(UWB)sensortechnologyandapplications

• Hybrid and monolithic integration of RF circuits for ultra-wideband and mm-wave systems


Reiner S. Thomä

Telefon +49 3677 69-2622

Telefax +49 3677 69-1113

reiner�thomae@tu-ilmenau�de



TU Ilmenau

Helmholtzplatz 2

Helmholtzbau, Raum 1516a

98693 Ilmenau

www�tu-ilmenau�de/it-emt

Ultra-wideband sensing applied for search and rescue of earthquake victims (top) and medical imaging (left).

51



Internet

Contact

Research Topics

Package solutions.Other areas of interest are driven by harsh operating envi-ronments for microelectronics. Aspects like high tempera-ture interconnect technology, cooling solutions for power electronics or high ampacity are in the focus of these fields.Silicon-on-ceramics composite substrate technology (SiCer), which is based on a novel bonding process between nano structured silicon and unfired LTCC, is another focal point of interest. Process and application related projects are being pursued for this technology.

EducationThe group offers lectures for undergraduates and graduate students as well as training courses for external industrial customers. The internal lectures are available for students in electrical engineering, mechanical engineering, micro- and nanotechnology and industrial engineering. The courses cover the basics of electronics technology, such as printed circuit board materials, design and manufacturing techno-logies or component assembly. Further lectures put em-phasis on microelectronic component packaging, specific technology requirements for high power or high frequency & microwave circuitry and ceramic based substrate materi-als. Students are also offered workshops in our group labs to manufacture printed circuit boards, thick film circuits or LTCC substrates.

GroupThe group of Electronics Technology covers the field of microelectronic packaging between integrated circuits and systems. This includes electronic layout design, substrate manufacturing technologies and component assembly processes. Packaging of microelectronic components and systems is becoming more and more important to achieve the desired ever-increasing functionality. Particular reasons for this are related to the systems‘ technical specifications (e.g. working frequency, power loss, miniaturisation) and the environmental working conditions, such as temperature or temperature gradient, vibration or radiation. Handling of such systems requires an interdisciplinary approach consi-dering material property investigation, design optimisation (electrical, thermal and thermal-mechanical) and process technology development.

ResearchOur research activities focus on the exploitation of Low Tem-perature Cofired Ceramic (LTCC) materials for various purpo-ses. High resolution patterning technologies are being deve-loped to close the gap between the macro world and nano technology and to be able to achieve better functionality for microwave circuitry. Further integration based on embed-ding functional materials (high-k dielectrics, ferroelectrics, ferrite) is under research and will be used for RF-System-in-

Electronics TechnologyElektroniktechnologie

• LTCC Technology for 100 GHz + Circuits

• Packaging Technologies for Harsh Environment Applications

• Advanced Module Technology for Satellite Communication Systems

• Functional3D-Integration(System-in-Package)basedonLTCC

• Silicon-Ceramic-Composite Substrate Technology

• Mesoscale Fluidic Toolbox

• Packaging for Nanosystems


Jens Müller

Telefon +49 3677 69-2606

Telefax +49 3677 69-1204

jens�mueller@tu-ilmenau�de



TU Ilmenau


Meitnerbau, Raum 1�2�115

98693 Ilmenau

www�tu-ilmenau�de/mne-et

52



Internet

Research Topics

Contact

52

Research Topics

bilize the entire available power and energy the cells provide during their lifespan.Currently, we are investigating the numerical simulation of Lorentz force enhanced flow patterns within glass melts. The process of efficiently melting, refining, and homoge-nizing the melted glass is strongly dependent on the melt flow within the tank. In order to improve the glass quality and melting process efficiency, Lorentz forces influenced by externally generated magnetic fields are used to create addi-tional flow components.We are involved in one project within the Research Training Group “Lorentz Force Velocimetry and Lorentz Force Eddy Current Testing”: B4 - Optimization of magnet field distribu-tion. The Research Training Group is measuring the Lorentz forces with values between 10-11 N and 1 N while solving inverse problems to obtain the desired parameters in fluids and solids.

EducationWe offer master courses in „Electrical Power Engineering“ and „Electro and Material Technology“ as well as bachelor courses in „Control and Power Engineering“ and „Micro and Nanoelectronics and Electrotechnology“. The students will be enabled to develop and design electro-technological de-vices and machines, including controlling and handling.

GroupConcerning both teaching and research, the Electrothermal Energy Conversion Group deals with methods and processes of using electrical energy to directly treat various materials including metal melts, semi-finished parts, and work pieces. We combine electrical power engineering and material sci-ence, resulting in system knowledge for the technological use of the related electro-physical processes. We have close scientific connections to other divisions: the Power Electro-nic Group, Thermodynamics Group, Fluid Dynamics Group, Materials Science Group, Automatic Controls Group, and the Theoretical Electrical Engineering Group. Our future plans include the development of new materials, compon-ents, appliance systems, and control techniques. Thus, we can fulfill the state-of-the-art requirements set by materials and micro-technologies as well as by environmental and re-cycling technologies. The equipment and processes utilized for teaching and research are highly energy intensive and specific. Therefore, it is of greatest scientific importance that the theoretical, numerical, and experimental studies be in-terdisciplinary.

ResearchAn important research topic regarding electro-mobility was the investigation of the thermo-management of lithium ion batteries. Since the aging process of lithium ion cells is tem-perature dependent, controlled cooling is necessary to sta-

Electrothermal Energy ConversionElektrothermische Energiewandlung

• Induction heating and melting

• Electromagnetic control of electrically conducting liquids

• Solidificationandcrystallisationinstrongmagneticfields

• Dielectric capacitor heating, microwave heating

• Electromagneticshieldingbymodifiedbuildingmaterials

• Numericalsimulationofelectromagneticfieldsandofcoupledfields

• Temperaturefieldsimulation,flowfieldsimulation

Dr.-Ing.

Ulrich Lüdtke

Telefon +49 3677 69-1510

Telefax +49 3677 69-1552

fg�elektrowaerme@tu-ilmenau�de



TU Ilmenau


Kirchhoffbau, Raum 2041

98693 Ilmenau

www�tu-ilmenau�de/ees-eew

53



Internet

Contact

Research Topics

Special equipment

• CAD lab: Laboratory with workstation and PC work-stations for AutoCAD, Autodesk Inventor, Solid Works, Catia, software for cost estimation, Pro/ENGINEER, Techoptimizer

• Flexible audiovisual stereo projection device (FASP): 3-sided CAVE unit with adjustable screens, wave field synthesis to generate realistic audio impressions

• Acoustic measuring equipment (structure-borne and airborne sound)

• Adjustment laboratory: Comprehensive measuring and controlling equipment to develop and simulate effici-ent adjustment techniques for mechanical and optical components

Services offered

• Conceptual design and detailed design• Consulting in the selection, use and integration of CAx

systems• Design reviews, error analysis of design documents and

products• Development, simulation and automation of adjust-

ment processes• Use of Virtual Reality (VR) in product development

Engineering DesignKonstruktionstechnik

• Design theory and methodology

• Modelling of functional structures and technical principles

• Variational and modularised design, feature technology, constraint-solving, knowledge-based engineering

• Use of audiovisual VR technologies in product development

• Fundamentals of embodiment design in product development

• Integration of embodiment design and calculation/simulation

• Cost analysis and cost reduction in product development

• Adjustment concepts for precision engineering products


Christian Weber

Telefon +49 3677 69-2472

Telefax +49 3677 69-1259

christian�weber@tu-ilmenau�de


TU Ilmenau

Max-Planck-Ring 12

Haus F, Raum 4250

98693 Ilmenau

www�tu-ilmenau�de/konstruktionstechnik

54



Internet

Contact

Education The staff of the group is provides lectures at the master and bachelor level. Regularly offered lectures are e.g. experi-mental physics, semiconductor physics, laser physics, pho-tovoltaics, organic photovoltaics, physical optics and opto-electronic devices. Furthermore, the group is in charge of the organization and execution of the lab training “Experi-mental physics”. The PhD-Graduate School for Photovoltaics „PhotoGrad“ - From cell to system is managed by the group. At the moment, more than 9 PhD students are accompli-shing their doctoral thesis with topics on, e.g., polymer solar cells, Si-solar cells, optics and superconductivity.

GroupThe group is made up of three research groups dealing with inorganic semiconductors and devices, organic semiconduc-tors and corresponding optoelectronic devices, and solar-energy components.

ResearchA variety of experimental methods for the investigation of optical, spectroscopic, optoelectronic and structural pro-perties are applied to a wide range of problems taken from semiconductor physics, polymer physics, photovoltaics, op-tics and material science. The group possesses all necessary technological equipment for the production and the valida-tion of polymer solar cells. Recent research results and pu-blications address bandstructure, optoelectronic properties and application of group-III nitrides, metal-oxide and chal-copyrite semiconductors; the nanostructure-property relati-on of polymer composite films; the charge separation, carri-er transport and absorption at polymer heterojunctions; the production and investigation of novel polymer solar cells. Many results have been obtained from close collaboration with world-wide leading research groups.

New Head: Prof. Dr. Stefan Krischok (page 76)

Experimental Physics IExperimentalphysik I

Technical Physics ITechnische Physik I

• Optical, electronic and structural properties of inorganic semiconductors

• Semiconductor hetero- and nanostructures for optoelectronic devices, sensors and solar cells

• Structure-propertyrelationofthinfilmsmadebyconjugatedpolymers

• Design, preparation and investigation of novel polymer solar cells

• Evaluation of photovoltaic and solarthermal components

• Further development of several optic-spectroscopic methods


Gerhard Gobsch

Telefon +49 3677 69-3701

Telefax +49 3677 69-3173

gerhard�gobsch@tu-ilmenau�de


Naturwissenschaften

TU Ilmenau

Langewiesener Str� 22

K&B expert, Raum 32

98693 Ilmenau

www�tu-ilmenau�de/techphys1

Research Topics

(until30September2014)

(from1October2014)

55



Internet

Contact

Research Topics

can be tracked in real-time clarifying their role in the func-tional properties of the material/system under scrutiny. Importantly, experiments can be performed both in the low perturbation limit, where the system is close to ther-mal equilibrium, as well as in the strong excitation regime. In the latter case various phase transition can be optically driven, enabling both new insights into these materials as well as external control of their functional properties.In the group several experimental techniques are being developed, optimized and utilized, ranging from time-resolved THz spectroscopy, enabling access to low energy excitations, to femtosecond electron diffraction, where atomic motion is investigated on the femtosecond timescale.

Education The group of Experimental Physics II offers lectures, pro-blem classes and laboratory courses on fundamentals of physics for students of engineering disciplines as well as lectures on experimental physics for bachelor students in Physics, Optronics and Materials Science. It also contributes to the master-degree programs Physics and Optronics with laboratory courses in photonics and lectures in Photonics and optoelectronics.

GroupThe group „Experimental Physics II“ is engaged in re-search concerning Optics and Photonics and is a mem-ber of the IMN MacroNano® and the Institute of Physics. The group is also committed to teaching physics courses, from basic classes in experimental physics to specialized classes in non-linear optics and modern spectroscopic techniques.

Research The group’s research focus lies in the field of ultrafast phe-nomena in advanced solids, ranging from metals, metallic nanostructures, organic and anorganic semiconductors, with emphasis on photovoltaic applications, to correlated electron systems. In many of these solid state systems the material’s functional properties are being controlled by the particularities of the interaction/interplay between the dif-ferent subsystems (electrons, spin, crystal lattice). To stu-dy and understand these interactions the time-resolved techniques, which were (and are being) developed in the last decades, could make a decisive contribution. Here a femtosecond pulse is used to drive the system out of equilibrium, while the suitably delayed light (from Terahertz to X-ray range) or electron pulse is used to track the re-laxation back to equilibrium. Thereby different excitations

Experimental Physics IIExperimentalphysik II

• Ultrafast phenomena in advanced solids

• Light-matter interactions

• Femtosecond electron diffraction

• Linear and time-resolved terahertz and optical spectroscopy

• Correlated electron systems

Univ.-Prof. Dr. rer. nat.

Jure Demsar

Telefon +49 3677 69-3672

Telefax +49 3677 69-3770

jure�demsar@tu-ilmenau�de

www�tu-ilmenau�de/exphys2

Fakultät für Mathematik und Natur-

wissenschaften

TU Ilmenau

Unterpörlitzer Straße 38

Gebäude V Raum 202

98693 Ilmenau

56



Internet

Research Topics

Contact

as a cliché for gravure printing. Another microstructuring process is redrawing glass for capillaries and holey fibers. The surface research is focussed on first reactions on juve-nile glasses, degradation, prerequisites for proper coating, and development of coatings.

EducationLectures and practical courses are given for bachelor and master students in materials science, in optronics, micro- and nanotechnologies, mechatronics, biomedical engi-neering, regenerative energy technology, automotive and mechanical engineering. Mandatory lectures cover, e.g., fundamentals of material science and technology of glasses and ceramics. Optional courses on electromagnetic proces-sing, recycling, biocompatible materials, glass coatings and production of optical materials are also offered.

GroupThe group is a member of the Institutes of Micro- and Na-notechnologies and of Materials Engineering. Our team is specialized in the science and engineering of glassy and ceramic materials. The equipment comprises special furn-aces for glass processing and a broad spectrum of chemical, thermal, optical, and electrical analysis methods for glasses, ceramics and powders. Some particular assets to be quo-ted are electromagnetic disintegration, quenching and fine annealing, laboratory cliché printer, mask aligner and dip coater.

ResearchThree highlight topics of our research are magnetic fields, microstructuring and surfaces. The use of magnetic fields in glass processing and in process control is investigated in close cooperation with industrial partners as well as in fundamental research projects. Na-noscaled magnetic fine powders with tailored properties for electromagnetic shielding are produced via a glass crystalli-zation technique. The glass crystallization route is also exploited in micro-structuring: a photostructurable glass has been developed in our group.Using photolithograpy, geometrical design and optical properties of this material can be trimmed for ap-plications such as microactuators, microfluidic systems and

Inorganic-Nonmetallic MaterialsAnorganisch-nichtmetallische Werkstoffe

• Glass and ceramics

• Materialsinmagneticfields

• Microstructuring

• Surfaces and coatings

• Materials development, production, post-processing and recycling


Edda Rädlein

Telefon +49 3677 69-2802

Telefax +49 3677 69-1436

edda�raedlein@tu-ilmenau�de


TU Ilmenau



98693 Ilmenau

www�tu-ilmenau�de/anw

57



Internet

Contact

Research Topics

Special equipment

• Digital high-speed camera: monochromic 4500 images/sec, 256x256 pixels

• 50 kN-, 10 kN universal testing machines: tensile-/pres-sure tests on parts, springs, wire materials

• Torsion testing machine: for (wire) material samples and parts up to 100 Nm

• Tribometric measuring system (translational, rotatory) for higher loads: determining friction coefficient and wear for material samples and parts at normal forces from 100 N to 1500 N

• Determining wear due to vibration (translational) at fre-quencies up to 50 Hz

• Servohydraulic test machine for dynamic loads• Vibration stability testing machine for springy elements

(swing arm by IABG)• Torsion test bench for push loaded rotating parts: for

clutches, cardan shafts and similar parts up to 200 Nm peak value at 50 Nm nominal torque

• Rotating bending test stand for straight rod-like speci-mens

• Optical image processing measuring station for springs• Test benches for dynamic spring tests• Optical microscope with colour camera

Services offered

• Testing and assessment of the initial material (wire) for spring manufacturing

• Calculations of spring functions and strength (incl. FEA and MBS)

• Consulting on spring manufacturing, design and use of springs

• Spring inspection (characteristics, transverse forces, re-laxation, durability)

• Torsion tests of material and components (static and dynamic)

• Conceptual design, engineering and installation of test benches

• Execution and evaluation of high-speed video records• FEA calculations (static, vibration behaviour)• Tribologic material- and part studies• Software engineering for spring calculation (dimensi-

oning)

Machine ElementsMaschinenelemente

• Calculation and numerical simulation of springs

• Exploring the spring manufacturing process

• Engineering of measurement devices for static and dynamic parameters

• Experimental determination of static and dynamic spring parameters

• Exploring the forming characteristics of spring wire

• Tribologic explorations of springs and pumps


Ulf Kletzin

Telefon +49 3677 69-2471

Telefax +49 3677 69-1259

ulf�kletzin@tu-ilmenau�de


TU Ilmenau

Max-Planck-Ring 12

Haus F, Raum 4260

98693 Ilmenau

www�tu-ilmenau�de/maschinenelemente

58



Internet

Research Topics

Contact

ators, optoelectronic parts, materials for energy transport, energy conversion and improved energy efficiency. Our ana-lytical methods – besides conventional methods – include, for example: X-ray diffraction (XRD), stress and strain ana-lysis, analytical scanning electron microscopy (SEM, EDX, EBSD), analytical transmission electron microscopy (TEM, EDX, EELS, STEM), scanning microprobes (STM, AFM), glow discharge spectroscopy (GDOS), X-ray fluorescence analysis (XRF), non-destructive testing (NDT) and mechanical testing by nanoindenter measurements.

EducationThe chair Materials for Electronics and Electrical Engineering is actively participating in teaching for many degree pro-grams (Materials Science and Engineering, Electrical Engi-neering and Information Technology, Micro- and Nanotech-nology, Mechanical Engineering, Mechatronics, Optronics, Automotive Technology, Biomedical Technology, etc.). This comprises lectures, exercises, seminars, lab courses, pro-jects, bachelor and master theses, PhD theses, colloquia and even labs for school classes. Starting with the basic funda-mentals of materials science and engineering, we teach all courses in an illustrative manner by including many practical examples and actual research topics. We also host many fo-reign guests and students.

GroupThe chair „Materials for Electronics and Electrical Enginee-ring“ is thoroughly engaged in teaching and research con-cerning all materials related topics at the TU Ilmenau. The chair is a member of the IMN MacroNano® and the Institute of Materials Engineering (IWT). It is also a founding member of the Center of Micro- and Nanotechnologies (ZMN), where it operates the central lab for materials analysis and thin film measurement and several facilities for thin film deposition.

ResearchThe research topics of the chair cover a wide field of ma-terials for electronics and electrical engineering, ranging from basic materials science to materials engineering for industrial applications, covering new material development, materials testing and analysis, and the processing of advan-ced materials systems. Research projects (DFG, AiF, State of Thuringia, and Industry) are dealing with production, properties, structuring and modification of thin films and functional materials. Further research aspects lie in the de-velopment of new materials and processes for micro- and nanotechnologies. The chair also hosts and runs the Thu-ringia Testing Center for Thin Film and Materials Properties (MFPA ). Some topics are, for example: development of materials and processes for micro- and nanotechnology, materials for energy technologies, sensors, contacts, actu-

Materials for Electronics and Electrical EngineeringWerkstoffe der Elektrotechnik

• Materials for Energy Technologies, Thin Films, Surface and Coatings Technology, Material Deposition Technolo-

gies, PVD

• Multilayered,compoundandcompositefilms,metallisation,functionalfilms,contacts,bonding,andlead-free

soldering for microelectronics and micromechanics

• Materials for sensors, actuators, photovoltaic, energy conversion and energy storage

• Materials for Electrical Engineering, contacts, isolation, magnets, dielectrics

• MaterialsAnalysisandMaterialsTesting;thinfilmmeasuringtechnologies,Non-DestructiveTesting(NDT)of

Materials;TestingCenterforthinfilm-andmaterialpropertiesIlmenau(stateinspectionauthority,certifiedafter

DINENISO/IEC17025).

• Development of new materials and new processes for advanced technical applications

• Design, Processing and Properties of micro- and nanostructured materials


Peter Schaaf

Telefon +49 3677 69-3610

Telefax +49 3677 69-3611

peter�schaaf@tu-ilmenau�de



TU Ilmenau



98693 Ilmenau

www�tu-ilmenau�de/wet

59



Internet

Contact

Research Topics

Services offered

• Modelling of mechatronic systems (structural dyna-mics, FEA, MATLAB, Simulink)

• Simulation of mechatronic systems• Model analysis and identification• Study of vibrations• Nonlinear vibrations (modelling, explorations)• Conceptual design of actuators, engines and drives• Controller engineering• Optimization of electromagnets and magnetic systems• Measurement of magnetic properties Special equipment

• Laser vibrometer• Lab for multi-coordinate drives • Lab for fluid mechatronics • Test vehicle• dSpace systems• Thermocabinets• Differential GPS• Inertia platform (acceleration values, rotary rates)• Load platform for force measurement with 6 degrees

of freedom

MechatronicsMechatronik

• Drives, engines and actuators

• Piezotechnology and magnet technology

• Passive and active vibration damping

• Vibration technology

• Structural dynamics

• Design of mechatronic and adaptive systems


Thomas Sattel

Telefon +49 3677 69-2486

Telefax +49 3677 69-1801

thomas�sattel@tu-ilmenau�de


TU Ilmenau

Max-Planck-Ring 12

Haus F, Raum 2120

98693 Ilmenau

www�tu-ilmenau�de/mechatronik

60



Internet

Research Topics

Contact

expansion (ZTE) and high Young’s modulus, Ceramic matrix composites (CMC), Superelastic shape memory alloys (SES-MA) and Investigation on the tribological behaviour of solid materials to ice.

EducationMWV offers lectures in many degree programs (i.e. mecha-nical engineering, automotive engineering and materials science). These programs include lectures, exercises, semi-nars, lab courses, projects, bachelor and master theses, PhD theses and colloquia. To develop a student s expertise, all activities within the MWV are individually coordinated to either allow the students to specialize in a topic or to be-come a generalist, with an excellent understanding of the basic concepts. We also host foreign guests and students.

GroupThe group of Metallic Materials and Composites (MWV) was founded in 1996 at the Ilmenau University of Technology. The group MWV is engaged in teaching and research con-cerning all metallic materials related topics, especially hybrid materials, composites and multi materials design. The group is a member of the IMN MacroNano® and the Institute of Materials Engineering (IWT). Concerning both teaching and research, the group deals with the characteristics, analysis and development of metallic, hybrid and cellular materials. Currently metallic materials are the most used materials in the world. The development of new metallic materials and multi-material-systems, with at least one part made up of metallic materials, is of crucial importance for future appli-cations.

ResearchThe research topics of the group cover a wide field of mate-rials for lightweight application in automotive and mecha-nical engineering, ranging from basic materials science to materials engineering for industrial applications, covering new material development and materials testing and analy-sis. The core expertise of the group can be found in the area of characterization of metallic materials, development of multi-material-systems and development, production, cha-racterization of cellular metals, materials with zero thermal

Metallic Materials and CompositesMetallische Werkstoffe und Verbundwerkstoffe

• Characterisation and application of metallic materials, analysis and optimisation of materials

• Mechanical behavior of metallic materials

• Analysis and optimization of manufacturing processes

• Materials with combined characteristics, material systems, multi-material-design

• Cellular metals

• Hybrid materials and structures

• Lightweight design

Univ.-Prof. Dr.-Ing. habil. Dr. h. c.

Heinrich Kern

Telefon: +49 3677 69-2450

Telefax: +49 3677 69-1597

heinrich�kern@tu-ilmenau�de


TU Ilmenau



98693 Ilmenau

www�tu-ilmenau�de/mwv

61



Internet

Contact

Research Topics

EducationAmong the fields for which the Institute is responsible, the group of Micro- and Nanoelectronic Systems is in charge of the following main fields of teaching: Theory of micro- and nanoelectronic systems, Micro- and nanosensors, Circuits manufactured according to the customer‘s requirements (ASICs), Research seminar – Micro- and nanoelecronic sys-tems, Physical principles and applications of scanning probe technology, Micro- and nanosensor technologies, Opto-electronics, Integrated Circuits Design, Acoustoelectronics/microacoustics, Integrated analog and digital circuits and dimensioning of photovoltaics systems.

GroupThe group of Micro- and Nanoelectronic Systems is engaged in the further development of micro- and nano-electronic systems in basic research as well as in applied research. The integration and functional combination of extremely minia-turized electric and nonelectric micro- and nanotechnolo-gies tend to result in a synergetic combination of efficien-cies.

ResearchThe core expertise of the group can be found in the area of micro- and nanofabrication, sub-5nm lithography, plas-ma etching, nanoelectronics, transistor based spectrometer, single ion implantation, cantilever-microsystems, fast scan-ning probe imaging, nanoresonators, attogram mass detec-tors, microactuators, developement of nanostructures and cantilever-based sensors (AFM, electronic nose, ARCH inf-rared sensors). More than 360 scientific papers, 41 funded projects, coordinating one IP-Project, 65 invited talks, 126 conference presentations and 43 patents show the interna-tionally recognized research of 29 scientific workers in the Group of Micro- and Nanoelectronic Systems.

Micro- and Nanoelectronic SystemsMikro- und nanoelektronische Systeme

• Nanostructure technology and characterisation

• Nanometer electronics and NEMS design

• Micro- and nanoelectronic systems and their implementation

• Software tools for the design and simulation of MEMS, NEMS and integrated circuits

• Nanotechnology for single-electron-and quantum-devices

• Nanomechanics

• Nanosensors

• Scanning Probe Microscopy

• Scanning Probe Lithography

• Mirco-Nano-Integration


Ivo W. Rangelow

Telefon +49 3677 69-3718

Telefax +49 3677 69-3132

ivo�rangelow@tu-ilmenau�de



TU Ilmenau


Kirchhofbau, Raum K2018

98693 Ilmenau

www�tu-ilmenau�de/mne_mns

62



Internet

Research Topics

Contact

that “measure” and store an indicator without need for electrical power. The read out can, however, be done by RFID transponders. Among the those fully passive sensors developed so far are temperature-time integrators, gas de-tectors and a mechanical shock counter. MOEMS currently face a revival of integrated optics. New high accuracy technologies enable optical sensors at short wavelengths. In combination with Si-based fibre pigtails, powerful measurement systems such as microtrackers have been realized. MMS has been project leader for KD Optimi for Ilmenau. For microoptics new concepts for tunable prisms or lenses based on AlN membranes are investigated. AlN is an excel-lent replacement for PDMS / silicone films with no creep un-ter load. AlN thin films are highly reliable and transparent. Complex microoptical systems are designed and manufac-tured, e.g. as part of the DFG Priority Program 1337 - Active Micro-Optics. In microfluidics, MMS is involved in the de-sign and optimization of fluid actuation by electrowetting on dielectrics (EWOD) or electrostatic forces. EducationThe group offers key lectures, Bachelor and Master thesis for several degree programs. Additionally, Prof. Hoffmann is in charge of the DFH/UFA integrated degree program with École Nationale Supérieure de Mécanique et des Microtechniques (ENSMM) in Besançon, France, in micromechatronics.

ChairThe Chair for Micromechanical Systems is part of the Insti-tute of Mechatronical Systems Integration at the Faculty of Mechanical Engineering. The focus of the group is the de-sign and the fabrication of MEMS and NEMS for applica-tions in life sciences, photonics and energy-efficient sensing. Especially the integration of functional nanostructures into MEMS is an extending area of research. The group is key operator of silicon-based technologies at ZMN.ResearchThe technological focus is set to nanostructured interfaces for integration into MEMS. Nanocrystalline aluminum ni-tride (AlN) thin films are an excellent membrane material with piezoelectric properties. Silicon can also easily be na-nostructured itself by RIE (Black Silicon) or by DRIE (Si grass). Both types of nanostructures allow numerous applications such as optical interfaces (moth eye effect), enhanced (de-)wetting (“lotus effect”) or mechanical interfaces, especially with additional coatings. Systems integration is the second important field of re-search. Here, a close cooperation with partners from appli-cations is intended. A detailed knowledge of the restrictions and requirements becomes more and more important for the development of microsystems. Non-electrical power sensors for RFID applications: sensors

Micromechanical SystemsMikromechanische Systeme

• MOEMS and RF-MEMS

• Energy-efficientsensorconceptsandnon-electrical-powersensors

• Electrowettingandmicrofluidicsforlifesciences

• 3DnanostructurefabricationandNEMS(micro-nano-integration)

• Nanocrystalline AlN on silicon as a mechanical material


Martin Hoffmann

Telefon +49 3677 69-2487

Telefax +49 3677 69-1840

martin�hoffmann@tu-ilmenau�de


TU Ilmenau

Max-Planck-Ring 12

Haus F, Raum 3110

98693 Ilmenau

www�tu-ilmenau�de/mms

63



Internet

Contact

Research Topics

sensor is to be integrated to give a better insight into cel-lular processes of the cells that are cultivated in such micro bioreactors.

Within this framework is the development of hybrid systems for the cultivation and the measurement of electrogenic cells e.g. cocultivation of microfluidic two chamber systems. Further extensions of these research approaches are novel, hybrid 3D structures such as 3D multielectrode systems ap-plicable for microbioreactor systems or in medical devices. Such systems are based on assembly and connection tech-nology and on variants in structuring glass, which has some extraordinary features, with respect to biological applica-tion, such as biocompatibility and optical transparency.

For the development of biomedical and pharmaceutical test devices, we need an interdisciplinary approach involving bi-ological, chemical and biochemical expertise. Therefore, the new group nanobiosystem research consists of engineers, (bio)chemists and physicists. The research on technical de-vices is attended by basic research efforts concerning the underlying chemical and biological processes as well as ad-aptations regarding biological assays or chemical surface modifications.

Applications of nanotechnology and microtechnology lead to a field which could be called nanosystemintegration. The next step is the development of nanobiotechnological sys-tems, which could reflect the hierarchical organization of biological systems that utilise scales and laws of nature on all metric levels.

As one example of such systems, we present the design and construction of a new class of micro bioreactors. It has been shown that 3D cell culture systems reveal the in vivo situati-on much better than the cultivation of one cell type alone. For this purpose we have to construct and arrange fluidic devices and a cell-biological environment in such a way that living cells can survive in a three-dimensional, organ-like structure, enabled by technical devices. Such organ-like cell structures may lead to new ways in medicinal chemistry for the determination of ADME/Tox properties of potential drugs. One part of the construction principle is the integra-tion of sensors, preferably novel AlGaN/GaN nanosensors.

The latter nanosensors offer the possibility to estimate reactions of cells attached to the sensor surface in a non-destructive and label-free manner. These sensors are highly sensitive and biocompatible to cells. Furthermore, they are transparent in order to enable microscopic and other op-tical observations of the cells. In an advanced version, the

Nano-Biosystems TechnologyNano-Biosystemtechnologie

• Microfluidics,Microreactorresearchwithbiologicalandchemicalapplications

• Polymer scaffolds for 3D cell cultivation

• Process optimization

• Biosensor development e�g� AlGaN/GaN nanosensor

• 3D structuring of glass and hybrid systems

• Assay development e�g� for cancer research

• Nanosystemintegration


Andreas Schober

Telefon +49 3677 69-3387

Telefax +49 3677 69-3499



Naturwissenschaften

TU Ilmenau



98693 Ilmenau

www�tu-ilmenau�de/nbs

64



Internet

Research Topics

Contact

NanotechnologyNanotechnologie

www�tu-ilmenau�de/mne_nano

Thrust 1 is a new research area that is being established by Prof. Jacobs. The goal is to extend the application range of nanostructured materials and devices that we have learned to produce over the past 10 years. The challenge today is no longer the fabrication of a single device but the manufactu-ring and integration of functional materials and devices in heterogeneous systems. Applications that require integrati-on over large areas, in three dimensions, or on novel mate-rial independent substrates including flexible or stretchable materials are particular challenging. This requires a new set of nanomanufacturing tools. Thrust 1 aims to discover and develop the required solutions.

Thrust 2 is a more established area since it uses commercially available processes or processes that are no longer classi-fied as emerging. Specifically, Thrust 2 supports the growth, characterization and optimization of hetero-and nanostruc-tures processed from group III-nitrides, silicon carbide, and metal oxides on different substrates.

Both thrusts require a collaborative effort and continuo-us refinement of In-Situ and Ex-Situ analytical methods to study the materials, structures, and devices. We com-monly use ellipsometry, Auger electron spectroscopy, depthprofiling, and high resolution XRD.

The research requires both front and back-end processing to facilitate integration into heterogeneous systems. In a broader context the research supports cooperation within IMN MacroNano® on nanoelectronics, sensor systems, and smart materials. The nanostructured materials and deposition processes find applications in areas that deal with energy efficiency (Solid state lighting), energy storage, and energy conversion which are key strategic issues of the group and the university.

The scientific research also provides the basis for a well-founded and practically oriented education for studen-ts in the field of advanced semiconductor materials, nano-technology, clean room technology, and nanoanalytics.

Prof. Dr. Sc. Techn. ETH

Heiko O. Jacobs

Telefon +49 3677 69-3723 Telefax +49 3677 69-3709 heiko�jacobs@tu-ilmenau�de



TU Ilmenau



98693 Ilmenau

Thrust 1: Emerging nanotechnologies targeting heterogeneous integration:• Enable - integration of functional devices across traditional length scales & material boundaries• Through - invention of printing-transfer-& engineered-self-assembly processes• Incorporating – micro and nanoscopic devices including nanoparticles / wires-microscopic-dies & chiplets

Applications:• Cost effective production of solid state lighting panels•Novel stretchable and conformal electronics for bio-diagnostics including „ Electronic Tattoos“�•Nanoxerographic printers to enable low cost printing of 3D nanostructures for energy conversion / sensor applications• Noveldetectionofairbornthreadstargetingtheefficientcollectionofairbornparticles.

Thrust 2: Support of established Nanotechnologies: Epitaxial growth of group III-Nitrides, SiC and graphene,

Nanolithography, nanostructuring, structural and electrical heterostructure characterization, AES nanoanalytics,

Applications: high electron mobility transistors, pH sensors, MEMS/NEMS

65



Internet

Contact

Research Topics

responsible for adapting research in classical optical en-gineering and lens design into innovative optical (micro-)system technologies. We specifically focus on design, in-tegration, tolerancing, fabrication, and characterization of freeform optical elements in optical (micro-)systems. To re-alise novel prototype systems, we rely on our unique fabri-cation facility that combines both ultraprecision mechanical and laser machining in a single machining centre. Here we have developed many novel freeform elements and systems, e.g. for head-up displays for the automotive industry or for optical tweezing and optofluidic microsystems for biome-dical applications. In such a manner is our optical design specialization focused on broader multi-disciplinary goals. EducationTo ensure continued future success, our interdisciplinary re-search activities are complemented by a variety of gradu-ate and undergraduate degree programs. Young students taking the engineering Bachelor programs at TU Ilmenau (e.g. Optronics, Mechatronics, Electrical and Mechanical Engineering, Technical Physics) are exposed to interdiscipli-nary projects through a broad course selection. Challenges in optical engineering and microsystems are addressed in subsequent Master (e.g. Master of “Micro- and Nanotech-nologies”) and PhD programs like the Graduate School on “Optical Microsystems (OMITEC)” and “Green Photonics” funded by the Thuringian Ministry for Education, Science and Culture (TMBWK).

GroupHistorically at the Ilmenau University of Technology, re-search work in optics has been focused on addressing pro-blems that arise in both mechanical and precision enginee-ring. While always at the cutting edge, under the direction of Prof. Heinz Haferkorn, the role of educating and teaching students was enhanced and incorporated more prominent-ly into the research structure of the university with notable education-focused lectures such as “Theory of optical ima-ging systems”. Specifically during the 60’s and 70’s phy-sical aspects of optics were linked to the engineering and manufacture of precision mechanical systems through the development of 5th order aberration theory and the ana-lytic descriptions of imaging systems. While over the years personal changes have brought new faces to Ilmenau (Prof. Truckenbrodt in 1993, Prof. Sinzinger in 2002) and new de-velopments have shifted the focus of optical research, the same long-term dedication to education and the develop-ment of the next generation of scientists and engineers has been preserved. Modern research challenges have moved on to examining “microstructured and freeform optics for design and optimization of optical systems”.ResearchWe, the Group of Optical Engineering and the junior re-search group “Optik Design, Simulation und Modellierung optischer Systeme” (funded by the Carl-Zeiss-Stiftung), are

Optical EngineeringTechnische Optik

• Optics design

• Microoptical system integration

• Optical platform for Micro-Integration

• Freeform surfaces in optics - design, optimisation and manufacturing

• Optimisation of optical image systems with microstructured optics

• Modelling of optical imaging systems

• Opticalmicromanipulationandmicro-optofluidicsystems

• Digital holography

• Active optical microsystems


Stefan Sinzinger

Telefon +49 3677 69-2490

Telefax +49 3677 69-1281

stefan�sinzinger@tu-ilmenau�de


TU Ilmenau

Am Helmholtzring 1

Haus M, Raum 201

98693 Ilmenau

www�tu-ilmenau�de/optik

66



Internet

Research Topics

Contact

cepts. Signal processing theory can be used to reinterpret Fresnel diffraction, and the effects of sampling can now be considered. Numerical algorithms based on the fast Fourier transform, have been developed so that the propagation of light can be efficiently calculated. Imaging without lenses is common in digital holography where Fresnel diffraction is calculated numerically. In this group, we pursue fundamen-tal theoretical questions relating to the performance limits of digital imaging and speckle metrology systems. Deve-loping robust numerical calculation techniques, confirmed with special analytical solutions, mean that we can develop novel metrology systems. Confirming numerical and ana-lytical predictions with experimental results is the ultimate test. This is our guiding research principal, theoreticians using numerical and analytical models make predictions that our experimentalists confirm or disconfirm. As it was in 1816, so it is today, plus ca change, plus c’est la meme chose!EducationSeveral courses are taught in this group during the Winter and Summer semesters, including Introduction to Fourier optics and holography, Digital holography and Design op-tischer Systeme zur Energiebündelung. There is a strong emphasis on practical lab work in the courses and studen-ts are exposed early on to current research topics. Hence students pursuing Bachelor and Master thesis programs are therefore well prepared for conducting their own research projects.

In praise of analytical solutions:Historically modeling the propagation and diffraction of light has been an active research area. A major advance took place in 1816 in Paris, where a young Fresnel proposed a novel way of describing diffraction with the assumption that light was wave like in nature. His initial draft was sub-mitted for consideration by the French Academy of Sciences on the topic of diffraction. There would have been resi-stance to this wave description of light on the Academy’s committee, which included the formidable cast of Poisson, Laplace and Biot. Fresnel provided analytical solutions for several diffraction problems including diffraction by a straight edge whose predictions were confirmed by experi-ment. Poisson, in a bid to overturn Fresnel’s results, realized that one of his solutions could be extended to describe the diffraction field behind an opaque disk. Poisson’s solution made the improbable prediction that a bright spot should appear in the center of a shadow cast by the opaque disk. Befriended by Arago, further experiments were conducted and the celebrated Poisson spot was discovered! Now nearly 200 years later much has happened as can be seen from the huge variety of research being conducted in TU Ilmenau alone. It is therefore remarkable that the princi-pals of diffraction espoused by Fresnel are still being widely used today. Paraxial optical systems can be designed and analyzed within this framework. Speckle systems, widely used today in non-contact metrology, rely on these con-

Optical Design, Simulation and Modelling of Optical Systems

• Classical optical problems in diffraction and propagation

• Statisticalopticswithanemphasisonspecklefields

• Modeling and characterization of paraxial optical systems

• Speckle metrology systems

• Digital optics including digital holography and phase retrieval techniques

• Coherent and incoherent imaging systems

• Signal processing, including Fourier transform, fractional Fourier transform, Linear Canonical transform, Wigner

distribution function, sampling and signal representation

• Propagation of light in turbid media such as biological tissue

• Modeling and simulation of broad-band optical sources

www�tu-ilmenau�de/od

Jun.-Prof. Dr. Eng.

Damien Peter Kelly

Telefon +49 3677 69-2491

Telefax +49 3677 69-1281

damien-peter�kelly@tu-ilmenau�de


TU Ilmenau

Am Helmholtzring 1

Haus M, Raum 201

98693 Ilmenau

67



Internet

Contact

Research Topics

PhotovoltaicsPhotovoltaik

•Inorganicsemiconductorsanddevicestructures:

-III-V-semiconductors,silicon,germanium;III-V-,Si-,Ge-basedphotovoltaics(PV);-(100)-and(111)-surfaces

-crystalline,µ-crystalline,amorphousmaterialsforphotovoltaics(PV);bulkandinterfaceproperties,

preparation and analytics

•Solarcells,opto-electronicdevices:

-high-efficiency,3rdgeneration,concentratorPV;tandem/multijunctionsolarcells

-nanowire-andquantumwellsolarcells;silicon/thinfilmsolarcells

•Analytics/characterization:

-Opticalinsitu-spectroscopy(u.a.reflectionanisotropy/differencespectroscopy,RAS/RDS)

-Benchmarkingoftheopticalin-situsignalsemployingsurfacesciencetoolsinultra-highvacuum(UHV),also

in collaboration with external partners: XPS, UPS, LEED, FTIR, STM, LEEM

Univ.-Prof. Dr. rer. nat. habil. Thomas Hannappel

Telefon +49 3677 69-2566

Telefax +49 3677 69-2568

thomas�hannappel@tu-ilmenau�de

www�tu-ilmenau�de/pv

GroupPreparative and analytical work is devoted to preparing new highly efficient solar cells, in the form of thin epitaxial multi-layer systems and nanowires of III-V materials, epitaxial silicon and epitaxial germanium. Multi-junction solar cells are pre-pared with III-V materials applying the MOCVD/MOVPE tech-nique and representing the most efficient solar cell material. ResearchSolar energy conversion: Growth processes are monitored via optical in-situ signals allowing for systematic monitoring and for systematic improvements of the growth procedures. The in-situ measured optical signal shows whether desired interface and bulk properties and a specific surface recons-truction have been realized in the MOCVD reactor. A direct relationship is established between a specific optical signal and the corresponding surface reconstruction. This strategy is successful with a unique experimental tool. The latter enables contamination free sample transfer from the MOCVD reactor to ultra-high-vacuum. Thus, signals like LEED, UPS, XPS, AES, STM images, FTIR, and again RDS are measured in ultra-high-vacuum that characterize the specific surface reconstruction. More cost effective III-V solar cells can be realized by deposit-ing III-V materials on Si-wafers. EducationThe group is in charge of the new Master course “Renewable Energie Techniques” (MRET). Here, basics of

renewable energy conversion, novel concepts of energy con-version, thin film and 3rd generation photovoltacis, photo-electrocatalysis, epitaxial preparation and analysis of high-per-formance opto-electronic device structures, etc. are taught. Bachelor, Master and PhD students are supervised and new students are searched for new ideas and projects. Special equipment: - Metal-organic chemical vapor deposition/vapor phase epitaxy (MOCVD/MOVPE) - MOCVD-to- UHV-transfer system involving UHV-transport chambers, transfer to various UHV-based measure ment opportunities; - surface science: low energy electron diffraction (LEED), UV- and x-ray photoemission (UPS, XPS), Fourier transform infrared spectroscopy (FTIR), scanning tunnelling microscopy (STM), 4-probe-STM; optical in-situ spectroscopy (reflectance anisotropy spectroscopy, RAS)

Atomic resolution (STM) image of unusual (100) silicon


Naturwissenschaften

TU Ilmenau



98693 Ilmenau

68



Internet

Research Topics

Contact

for laboratory operations in biology and chemistry. There-fore, the plug-flow transport and the stepwise variation of concentrations in a larger series of nanoliter fluid segments is used for multistep synthesis with very narrow residence time distribution and for bioscreenings with highly resol-ved effector concentrations. Thus, binary and non-spherical plasmonic nanoparticles polymer and composit nanopar-ticles can be prepared with high homogeneity. The flow chemistry is applied for the realization of new process win-dows of special organic reactions in a much shorter reaction time and with high yield. The connection between micro dosing and cell cultivation inside fluid segments allows the determination of combinatorial toxic effects on procaryotic microorganisms and eucaryotic cells with smallest amounts of substances.

EducationThe group is involved in the education of engineers in technical physics, material sciences, micro and nanotech-nologies, biotechnical chemistry and miniaturized bio-technology. Lectures on physical chemistry, instrumental analytics, microreaction technology, molecular cell biolo-gy and nanotechnology as well as seminars and practical microreaction technology training are offered in these ba-chelor and master programs. In addition, recent general aspects of sciences were discussed in lectures concerning general concepts of natural evolution and ecogenesis.

Group and Cooperations The group was founded in 2001 as an endowed professor-ship of the Deutsche Bundesstiftung Umwelt (DBU, German Environmental Foundation) at the Faculty of Mathematics and Natural Sciences. The foundation of the group was motivated in response to the rapidly growing importance of micro reaction technology and its high potential for the further development of sustainable chemical technologies. In addition to research on microreactors and miniaturized microfluidic arrangements for chemical and biological appli-cations, the development of educational experiments using microreactor was one goal of the group. In the following years, several laboratory techniques have been established such as flow chemistry, cell cultivation, micro PCR, contact angle measurements, LCMS, fluorescence microscopy, SEM, AFM, centrifugal sedimentation spectroscopy, and optical spectroscopy.The research is based on cooperations with other groups in Ilmenau, academic and industrial partners in Thuringia and in Germany, and with international partners. Research pro-jects are (were) financially supported by DBU, DFG, BMBF, BMWi, STIFT and the state of Thuringia.

ResearchThe research is focussed on the exploration of specific advan-tages of micro fluidics, in particular for multiphase systems

Physical Chemistry / Microreaction TechnologyPhysikalische Chemie / Mikroreaktionstechnik

• Microsegmentedflowtechnique/droplet-basedmicrofluidics

• Applicationofmicrofluidicsinchemistryandminiaturizedbiotechnology

• Flow chemistry for nanoparticle synthesis

• Nanoparticlesinheterogeneousmicroflowcatalysis

• Cellcultivationinmicrofluidsegments

• Micro toxicology at the nanoliter level

• Characterization of microreactors

• Chemicalsensinginmicrofluidsegments


Michael Köhler

Telefon +49 3677 69-3700

Telefax +49 3677 69-3173

michael�koehler@tu-ilmenau�de


Naturwissenschaften

TU Ilmenau

Gustav-Kirchhoff Str� 1


98693 Ilmenau

www�tu-ilmenau�de/mrt

69



Internet

Contact

Research Topics

ResearchThe research topics given above can be seen as cross sub-jects regarding application technologies, machines and too-ling, processing technologies as well as industrial services. Research projects are executed on a scientific basis. The activities mostly originate from industry oriented tasks. Re-search projects are generally conducted either as publicly funded projects or as industrial research mandates. In addi-tion, joint research projects offer the possibility to combine both approaches. If required KTI offers project manage-ment capacities to ensure the project’s success. Addressed industry segments are automotive, packaging, MedTec and EET(OP).

EducationKTI offers lectures in the degree programs mechanical en-gineering, automotive engineering, mechatronics, optronics and materials science. Currently, a master program in Plastic Technologies is offered. Student projects are usually set up according to current research activities. To develop a student s competence, all activities within the KTI are individually coordinated to eit-her specialize in a topic or to become a generalist, with an excellent understanding of the basic concepts.

Group and CooperationsThe group of Plastic Technologies Ilmenau (KTI) was foun-ded in early 2009 at the Ilmenau University of Technology as an endowed professorship answering the growing im-portance of plastics technologies in Thuringia and thus clo-sing the gap in the local research community. One of the defined goals is to support the local industry by increasing cooperation between research and industry; therefore the three relevant areas of plastics technologies are covered - application technologies, machines and tooling and proces-sing technologies. To support the relevant topics, the KTI has widely used plastics processing technologies available, such as mold injection, extrusion, and blow forming as well as processing of thermosets. Furthermore, a variety of ana-lyzing technologies has been set up to determine material and processing characteristics. Another important element is industrial services; the focus here lies on small and medi-um sized companies that dominate the industrial landscape in Thuringia. The scope enfolds laboratory services, mold trials, R&D projects up to management consulting. KTI is part of an interdisciplinary network, which is activated cor-respondingly to the individual tasks and projects.

Plastics TechnologyKunststofftechnologie

• Industry(valuechainmanagementandmanufacturingsystems)

• EnergyEfficiencyinplasticsprocessingtechnology(machines,processes,drivetechnology)

• Functionalisation(materialcharacteristicsandprocesscorrelations,compressionmolding)

• Hybridstructures(fiberreinforcedplastics,multi-componentinjectionmolding)

• PETTechnology(packagingapplications,coldstraining)

Additional topics

Lightweight design, manufacturing technology, biopolymers, lifecycle analysis, industrial services


Michael Koch

Telefon +49 3677 69-2450

Telefax +49 3677 69-1597

michael�koch@tu-ilmenau�de


TU Ilmenau



98693 Ilmenau

www�tu-ilmenau�de/KTI

70



Internet

Research Topics

Contact

Main topics are the development of design strategies, gene-ral design of nano machines and sensor-actuator integrated mechanical subunits.The group keeps close contact to national and international research institutes, universities and industrial partners.Key words of further fields of activities are: aerostatic and kinematical guidings, ultra precise probe heads and high precision drive systems.

GroupThe group of Engineering Design, the Group of Machine Elements and the Group of Precision Engineering together form the Institute of Design and Precision Engineering (Insti-tut für Maschinen- und Gerätekonstruktion, IMGK).Research and education are focused on the field of precision instruments and machines.

EducationLecture series are provided in the fields of Mechanical and Optical Components for Precision Engineering, and the De-sign of Precision Instruments and Devices.The contents of the lecture series is being continuously up-dated in regard to the technological progress.High value is placed on self-reliant design work of studen-ts in small project groups based on industry related design tasks.

ResearchResearch work is concentrated in the area of ultra precision techniques. In particular, concentration is focused on the DFG funded collaborative research center SFB 622 “Nano Positioning and Nano Measuring Machines (NPM)”. Joint research work is also done together with the group of Engineering Design. The goal is to establish fun-damentals for the design and development of NPM.

Precision EngineeringFeinwerktechnik

• Design, installation and testing of ultra high precision positioning and measurement systems (for instance nano-

positioningandnanomeasuringmachines)

• Creation and development of design principles applied for precision and ultra-precision technology

• Development methods and tools for precision technology

• Design, build up and testing of mechatronic functional units for precision technology; (for example mechanical

andopticalprobes)

• Aerostatic and spring guidances

• Developmentofprinciplestosuppress(eliminate)mechanicalvibrationsoflowestamplitudes

• Mechanical-optical devices

Fig� 2: Fodel parallel lines� Line width/space 30 μm/30 μm (l� – green/REM;r.–cofired/REM)Univ.-Prof. Dr.-Ing.

René Theska

Telefon +49 3677 69-3957

Telefax +49 3677 69-3823

rene�theska@tu-ilmenau�de


TU Ilmenau

Gustav-Kirchhoff-Platz 2

Newtonbau, Raum 2030

98693 Ilmenau

www�tu-ilmenau�de/fwt

The z-axis actuation of the Nanomeasuring Machine in tetrahederal orientation (patent pending)

71



Internet

Contact

Research Topics

EducationAmong the fields for which the Institute is responsible, the group of Precision Metrology is in charge of the following main educational areas:• Nanopositioning and nanomeasurement technology• Displacement and angle measurement technology• Alignment and directional measurement technology• Surface metrology • Interferometric and laser measurement processes• Nanometrology and nanomeasurement• Nanoprobes, scanning probe microscopy, structural

analysis• Optical and tactile probe systems

GroupThe group of Process Measurement and the Group of Mechanical Engineering Measurement and Production Measurement and the Group of Precision Metrology toge-ther form the Institute of Process Measurement and Sen-sor Technology. At the Technische Universität Ilmenau, this Institute is in charge of teaching in the areas of process measurement, production measurement, sensor technology for automation engineering, computer-aided processing of measuring values, measurement dynamics, laser and precisi-on measurement, analysis and environmental measurement, and calibration techniques. The Institute fulfils its teaching assignments for the faculties of Mechanical Engineering, Electrical Engineering and Information Technology, Compu-ter Science and Automation as well as Economics Science. The Institute is also responsible for the academic training in the branch of study “Process Measurement and Sensor Technology”. The highly qualified and practically oriented student training is based on extensive research work in co-operation with a number of partners from industry and the BMBF (German Research Ministry), the DFG (German Research Society) and the Thuringian Ministry of Science, Research and Culture.

Precision MetrologyPräzisionsmesstechnik

• Nanomeasuring and nanopositioning technology

• Nanometrology

• Fibre coupled planar mirror interferometer and corner cube prism interferometer

• Multi-coordinate measuring systems

• Optical and tactile nanoprobe systems

• Calibration technology and calibration standards for nanomeasuring machines


Eberhard Manske

Telefon +49 3677 69-2822

Telefax +49 3677 69-1412

eberhard�manske@tu-ilmenau�de


TU Ilmenau



98693 Ilmenau

www�tu-ilmenau�de/cc-npmm

72



Internet

Research Topics

Contact

The group of Process Measurement is a part of the Institute of Process Measurement and Sensor Technology, together with the Group of Mechanical Engineering Measurement and Production Measurement.

At the Technische Universität Ilmenau, this Institute is in charge of teaching in the areas of • Process measurement • Production measurement• Sensor technology for automation engineering • Computer-aided processing of measurement values • Measurement dynamics• Laser and precision measurement• Analysis and environmental measurement• Calibration techniques.

The Institute fulfils its teaching assignments for the faculties of Mechanical Engineering, Electrical Engineering and Infor-mation Technology, Computer Science and Automation as well as Economics Science. The Institute is also responsible for the academic training in the branch of study “Process Measurement and Sensor Technology”.

Process MetrologyProzessmesstechnik

• High precision and dynamic force measurement and weighing technology

• Micro and precision weighing technology

• Development and investigation of high-resolution comparator scales

• Dynamic and static behaviour of temperature sensors

• FieldcalculationbymeansofFEA(temperature,mechanicalstress)

• Self-calibratingtemperaturesensorsandminiaturefixed-pointcells

• Investigationandmodellingoftheinfluenceofmicroclimateonprecisionmeasuringinstruments

• Signalfilteringanddisturbancequantitycorrection


Thomas Fröhlich

Telefon +49 3677 69-2822

Telefax +49 3677 69-1412

info�pms@tu-ilmenau�de


TU Ilmenau


Kirchhoffbau, Raum K 2005

98693 Ilmenau

www�tu-ilmenau�de/pms

Mass comparator system to determine 1 kg with the accuracy of 100 ng (standard deviation 10-10)

73



Internet

Contact

Research Topics

companies. Regarding joining technologies, a unique pro-position of the group is the solid state welding process, as for example diffusion or friction stir welding. In the field of joining, the synergies between melting and solid state pro-cesses allows true understanding of the mechanics and the metallurgy when joining different materials with each other as for example aluminum with steel, copper with aluminum or aluminum with titanium. Arc welding ( GMA ) as well as cladding (Arc and Plasma augmented arc) are perfomed on a robot in order to process 3D-parts as well.

EducationResearch and education are strongly connected in the group of production technology. The group is engaged in giving lessons, seminars and labs in the areas of materials, tech-nologies and manufacturing as for example in Materials Science and Engineering, Electrical Engineering and Me-chanical Engineering, Mechatronics, Optronics, Automotive Technology, Biomedical Technology etc.

GroupThe group of „Production Technology“ is situated in the fa-culty of Mechanical Engineering and engaged manyfold in teaching and research concerning classical as well as new production technologies. The group has a long history re-garding research at the interface between materials and production technology.

Research and EducationThe working structure in the group consists of a strong cor-relation between materials and their suitability to be pro-cessed, production technologies and their properties as well as manufacturing and its requirements to processes in order to achieve an efficient result in terms of money and product quality. Regarding this structure, the group focuses its re-search on cutting, joining and cladding technologies with the aim to develop technologies and methods in order to process new materials for innovative products and construc-tions.The group is equipped with turning and milling machines for macro- and for micromachining. Materials, cutting tools and their geometry and coating are assessed in order to achieve high reliability and lifetime. Furthermore, a laser lab is part of the group, where welding, soldering, brazing and cutting activities for light weight constructions are carried out for research purposes or in direct cooperation with industrial

Production TechnologyFertigungstechnik

• Joining technologies with a focus on light weight material and hybrid joints

• Joining of plastics with metals

• Processing of innovative materials as for example ELFT

• Laser manufacturing with high power and high brightness lasers

• Welding of hybrid joints for electrical application

• Chippingofmetalsandfibrereinforcedplastics

• Cladding technologies as well as arc welding

• Rapid tooling via arc welding technologies

• Diffusionbondingaswellassolidstatewelding(US-weldingandfrictionbasedprocesses)


Jean Pierre Bergmann

Telefon +49 3677 69-2981

Telefax +49 3677 69-1660

jeanpierre�bergmann@tu-ilmenau�de


TU Ilmenau

Neuhaus 1

Schützenhaus, Raum 109

98693 Ilmenau

www�tu-ilmenau�de/fertigungstechnik

74



Internet

Research Topics

Contact

tory programs, Bachelor-, Master-, and dissertation theses, students gain professional knowledge and experiences, and relevant skills like time management, team work, presentati-on, and project administration.Antennas: Smaller – better – invisible. These claims lead to challenges in the miniaturisation of antenna elements and arrays, increasing operational frequencies and frequency bandwidths, and adding adaptivity or functionality. Appli-cations concern vehicular antennas and intelligent transport systems, mobile communications, satellite-based navigation and communication, wireless sensor technologies , and ra-dio channel emulation.Circuits: Speed – efficiency – integration. Topics include novel circuit architectures on the basis of the latest semicon-ductor technologies. Novel natural and artificial materials are investigated for compact and low-loss passive and active circuits like high-efficiency amplifiers and tunable filters. Fa-brication techniques like ceramic multilayers combined with silicon technologies play a key role for hybrid or monolithic integration of complex modules.The research and development of RF-MEMS holds fascina-ting promises for circuit layout, performance, and integrati-on. Functions earlier achieved solely by semiconductor elec-tronics can now be accomplished also by micromechanical effects. Prominent examples include switches, controllable resonators, filters, and oscillators.

The RF and Microwave Research Lab deals with the propa-gation, interactions, and technical applications of electro-magnetic waves, and circuits, signals, and systems based on them, at frequencies between 100 kHz and 100 GHz. Me-thods include experimental precision measurements, nume-rical design, simulations, and theoretical analyses. The Re-search Lab, which is equipped with a modern infrastructure and unique antenna test facilities, forms part of the Institute for Information Technology in the Group for Electrical Engineering and Information Technolo-gy. Reflecting the interdependences between technologies, devices, and systems, the Research Lab is also a member of the interdepartmental Institute for Micro- and Nanotechno-logies and the Thuringian Centre of Innovation in Mobility.The RF and Microwave Research Lab contributes a high-level education for the study programmes of „Electrical Engineering and Information Technology“, „Computer Engi-neering“, „Communications and Signal Processing“, „Media Technology“ and „Optronics“, featuring classical and mo-dern aspects of RF and microwave techniques. In addition to compulsory courses, in-depth studies of mobile or satellite communications, antennas and wave propagation, audio- and video-technology, and radar are offered. The lecture courses are complemented and supported by illustrations, seminars, instructions to problem solving, labs, and possibi-lities to join the research team. In the framework of labora-

RF and Microwave Research LabHochfrequenz- und Mikrowellentechnik

• Antennas : Vehicular, tracking and navigation, ultra wide-bandand millimeter wave antennas, compact antenna

arrays,wirelesstransmissioninintelligenttransportsystems(ITS),antennameasurements(anechoicchamber,

near-andfar-fieldmeasurements),VISTA-VirtualroadSimulationandTestArea)

• High-frequencymicroelectromechanical(MEMS)devicesandcircuits

• RF and microwave circuit and system design: Fronted architectures, passive and active devices, integrated cir-

cuits,reconfigurablecircuitelements,metamaterialdevices

• RFandmicrowavecircuittechnologies:Ceramicmicrowave-multi-layermodules(LTCC),hybridintegration,ex-

pertiseinspacequalificationandon-orbitverification,frequency-domainandtime-domainmeasurements

• Electromagneticcompatibilityissues(EMCandEMCE)

Uni.- Prof. Dr. rer. nat. habil.

Matthias Hein

Telefon +49 3677 69-2831

Telefax +49 3677 69-1586

hmt@tu-ilmenau�de

Fakultät für Elektrotechnik und In-

formationstechnik

TU Ilmenau

Helmholtzplatz 2


98693 Ilmenau

www�tu-ilmenau�de/hmt

75



Internet

Contact

Research Topics

used. The RF & Nano Devices research group is developing extremely small and fast transistors. To this end we investi-gate non-classical device concepts like multiple-gate MOS-FETs and nanowires as well as novel materials like III-nitrides and graphene. The group closely collaborates with leading national and international groups in the field. Several on-going research projects are financially supported by the EU, by national funding agencies, and by the industry.

Education The group offers undergraduate and graduate courses to realize a high quality education for the students. The spec-trum comprises fundamental electronics courses and labs with the main topic on semiconductor devices. In our labs the students gain practical experiences. Already in the fun-damental courses the students gain a first insight in the method of experimental investigation of semiconductor de-vices. In our graduate courses, we offer special courses in the lab to increase the knowledge of experimental methods in the investigation of semiconductor devices and circuits.In our theoretical fundamental courses, we impart a com-petent knowledge of the function and operation of semi-conductor devices. In addition to these courses, we offer courses for nanoelectronics, high frequency devices, power semiconductor devices and circuits and polymer electronics.

GroupThe group is engaged in teaching and research on preparati-on, measurement and simulation of semiconductor devices and circuits. The main topics of our work are nano-MOS- and high frequency devices, power electronic devices and circuits and devices of the polymerelectronics. These topics are also reflected in our courses for the students in the fa-culty of Electrical Engineering and Information Technology in graduate education.

ResearchThe research focus is on the preparation, characterization and optimization of semiconductor devices. The polymer electronic research group is developing organic field effect devices. The activities comprise the preparation of low cost devices. While the organic light emitting dio-de is already in the commercial application, there are basic problems to solve in the field of organic transistors. Conse-quently , the goal of our investigations is the optimization of the device behavior.The power electronics research group is developping com-plex circuits (embedded systems). The main topic is con-cerned with sensor circuits, digital and analogous circuits, driver circuits and power electronic systems. The research activities are closely enforced by industry. As an example from CMOS technology, voltages up to 650V can now be

Solid State ElectronicsFestkörperelektronik

• Theoretical and experimental investigation on carrier transport

• Material characterization and parameter extraction

• Device simulation, modeling, and design,

• Deviceprocessing(togetherwithpartnersatTUIlmenauandexternalpartners),

• Electrical device characterization

PD Dr.-Ing. habil.

Susanne Scheinert

Telefon +49 3677 69-3714

Telefax +49 3677 69-3132

susanne�scheinert@tu-ilmenau�de



TU Ilmenau


Kirchhoffbau, Raum 2013 b

98693 Ilmenau

www�tu-ilmenau�de/mne-fke

76



Internet

Research Topics

Contact

molecule-surface interactions. This information is particu-larly important for improvement of electronic devices (e.g. transistors) and sensors and also for optoelectronic appli-cations.Our studies on indium oxide are motivated by its potential as a gas sensing material and the hope to tune the thermo-electric properties by varying structure and stoichiometry in order to produce self-sustaining gas sensing devices. Finally, ILs are a class of material with promising properties for many applications. Their low vapour pressure enables the material characterisation under vacuum conditions. Our studies aim for an understanding of the surface orientati-on of the molecular constituents, the behaviour of dissol-ved species as well as the chemical analysis of nanoparticles produced by the interaction of plasma with ILs containing metal ions.Our group is addressing the mentioned topics within several third party funded projects, including two priority projects of the DFG and in close collaboration with partners.The research group is involved in the Education of students. This includes regular lectures and seminars as well as super-vision of students during their studies for a Bachelor, Master and PhD degree. Besides regular teaching, the head of the group is the consultant for the students of Technical Physics.

The study of properties of surfaces and their interaction with molecules is in the focus of the research group. Knowledge about these topics on a molecular level is of key importance for the application of most materials – in particular due to the ongoing trend of miniaturization. In particular, we intensively investigate the properties of III-nitrides and heterostructures thereof, oxides (in particular In2O3), and Ionic Liquids (ILs) by combining different experi-mental methods in ultra high vacuum. Nitride growth for subsequent in-situ analysis is performed by plasma assisted Molecular Beam Epitaxy controlled by Re-flection High Energy Electron Diffraction. For surface inve-stigation, X-ray and Ultraviolet Photoelectron Spectroscopy, Metastable Induced Electron Spectroscopy, Auger Electron Spectroscopy, Low Energy Electron Diffraction, Photoelec-tron Emission Microscopy, Scanning Tunnelling and Atomic Force Microscopy are applied. Our Research focuses on a detailed understanding of sur-face properties and processes in particular of semiconduc-tors and ILs. By analysing chemical surface composition, chemical bonds, and structural as well as the electronic pro-perties of clean and adsorbate covered surfaces, important insights are obtained. Our studies on group III-nitrides provide information on the electronic structure of clean surfaces including surface band bending, surface reconstruction, interface band offsets and

Surface Physics of Functional NanostructuresOberflächenphysikfunktionellerNanostrukturen

• Surface and interface analyses

• Molecular beam epitaxy

• Materials:

Group III-nitrides

Oxides

Ionic liquids

• Study of clean surfaces, material-molecule interaction and chemical reactions at surfaces

• Surface functionalization and passivation

• Chemical and electronic properties

• Thermoelectrics

• Sensors

PD Dr. rer. nat. habil.

Stefan KrischokTelefon +49 3677 69-3202

+49367769-3405(ZMN)

Telefax +49 3677 69-3365

stefan�krischok@tu-ilmenau�de


Naturwissenschaften

TU Ilmenau

Gustav-Kirchhoff-Str� 7

Feymannbau, Raum 312

98693 Ilmenau

www�tu-ilmenau�de/funktof

(until30Sept.2014)

77



Internet

Contact

Research Topics

Services offered

• Mathematic models and numerical simulation for sys-tems and microsystems in mechatronics (optics, elec-tronics, mechanics)

• Model based signal processing, system monitoring and signal analysis

• Design of embedded systems

Special equipment

• Robot systems by the firms Festo and Kuka• d-space systems for rapid control prototyping (test of

signal processing on prototypes)• Measuring station for laser tracker systems

System AnalysisSystemanalyse

• Implementation of signal processing in embedded systems

• Modelbaseddataanalysisbymeansoftechniquesfromautomatedclassification,artificialneuralnetworksand

the fuzzy theory

• Signal and system models for deterministic and stochastic processes

• Knowledge based systems for decision making to solve complex tasks in engineering and environment

• System engineering for mechatronic systems and dimensional measuring systems in the nanometer range

• Assistance systems

• Microcontroller solutions


Christoph Ament

Telefon +49 3677 69-2815

Telefax +49 3677 69-1434

christoph�ament@tu-ilmenau�de


Automatisierung

TU Ilmenau

Helmholtzplatz 5

Zusebau, Raum 3006

98693 Ilmenau

www�tu-ilmenau�de/systemanalyse

78



Internet

Contact

GroupThe group of Experimental Physics I performs basic research in solid state physics of surfaces and interfaces. To this end, a home-built scanning tunelling microscope operated in ultrahigh vacuum and at low temperatures has become operational in October 2012. A second low-temperature microscope has been successfully installed in May 2013. With this instrument a combination of scannng tunnelling and atomic force microscopy experiments using the qPlus sensor are feasible. In addition an external magnetic field up to 2 Tesla may be applied perpendicular to the sample surface. Vibrational spectroscopy using an Ibach spectro-meter is the second main analysis technique of the group. ResearchThe group addresses modern solid state physics at sur-faces. In particular, the spin-dependent conductance of low-dimensional conductors is investigated with a rather unconventional approach: the tip of the scanning tunnelling microscope controllably contacts single atoms or molecules adsorbed to surfaces. These measurements enable the inve-stigation into charge and spin transport in the ballistic trans-port regime. With these experiments we have recently built an atomic spin valve, which shows that magnetoresistive ef-fects are relevant at the ultimate scale. Moreover, we have demonstrated the tunnelling and ballistic anisotropic ma-gnetoresistance using single-atom junctions. The impetus

Technical Physics I /Surface PhysicsTechnischePhysikI/Oberflächenphysik

Experimental Physics I/Surface PhysicsExperimentalphysikI/Oberflächenphysik

• Charge and Spin Transport through Single-Atom and Single-Molecule Contacts

• Magnetism at the Nanometre Scale

• Quasi-Particle Behaviour of Electronic and Vibrational Excitations

• Spectroscopic Investigation into the Organic-Inorganic Interface

• Advancement of Spin-Polarized Scanning Tunnelling Microscopy and Spectroscopy


Jörg Kröger

Telefon +49 3677 69-3609

Telefax +49 3677 69-3205

joerg�kroeger@tu-ilmenau�de


Naturwissenschaften

TU Ilmenau

Langewiesener Straße 22

K&B expert, Raum 30

98693 Ilmenau

www�tu-ilmenau�de/exphys1

for this main research direction of the group is unravelling opportunities and limits of molecular and spin electronics at a fundamental level. In addition, excitation spectra of single atoms and molecules are used to understand interactions between electronic, magnetic and vibrational degrees of freedom, which are at the base of the quasi-particle picture in solid state physics. The German Research Foundation and the Carl Zeiss foundation are funding research projects dea-ling with the Kondo effect of single magnetic impurities, the influence of the tip on exciting and probing single-atom and single-molecule vibrations, graphene on metal surfaces, and superconducting single-atom junctions.EducationTeaching is provided at the bachelor and master level. Lec-tures, problem classes and seminars in Experimental Physics, Solid State Physics, Surface Physics, Scanning Probe Methods and Physics of Nanostructures are examples for regularly offe-red teaching activities.

Pseudo-three-dimensional presentation of a scanning tunnelling microscopy image of 14 Pb-phthaloyanine molecules on Ag (111). Molecules were arranged with the tip of the instrument to show initials of the Technische Universität Ilmenau.

Research Topics

(until30September2014)

(from1October2014)

79



Internet

Contact

Research Topics

Polymeric materials by thermal processes and ionizing radi-ation undergo structural changes (aging) leading to marked modification of their mechanical, dielectric and optical pro-perties. Currently, aging studies are performed in both syn-thetic and natural polymers (biopolymers) using the com-bination of several techniques available in the group and mentioned above. In this way, the problem is tackled from different fronts and the study of static (structural) and dyna-mic properties can be performed.

Teaching includes a wide spectrum of classes, tutorials and labs in experimental physics. For master students and PhD candidates the focus is put on soft matter physics and NMR in both theoretical and experi-mental aspects. The research projects that are currently de-veloped in the group are the best foundation for education, by transferring personal research experiences to it as well as by engaging students as fellow-researchers in current and tangible projects

The group of Technical Physics II / Polymer Physics is speci-alized on research in the field of polymer science and com-plex fluids in its bulk state as well as under confinement. Research involved both theory and experimental parts. The main experimental area in the group is Nuclear Magnetic Resonance (NMR). The applications of NMR span a wide range of scientific disciplines, from physics to biology and medicine. The group is equipped with a complete set of last generation NMR scanners and spectrometers covering both high and low magnetic fields. A strong expertise in X-ray technique is also offered; the group is equipped with two X-Ray Diffractometers. The research group has a strong inter-national profile and is currently collaborating with scientific groups in several countries around the world.

Currently, biopolymers comprise an important area of re-search in the group. Biopolymers films are studied using NMR, X-ray diffractometry and calorimetric techniques. Interesting features found in these kinds of materials re-garding structure and dynamics are stimulating further re-search in this area. We have shown how some microscopic properties vary both in function of space and time during film formation.

Technical Physics II / Polymer PhysicsTechnische Physik II / Polymerphysik

• NMR on polymers and soft matters

• Characterisation of porous media: Geophysics, ceramics, glass materials

• Noncontacting measurement of reaction and polymerisation

• Coatings,lacquers,films:Drying,agingandcomposition

• X-ray scattering on polymers and layer structures

• Imagingoftransportincomplexfluids

• Microfluidicsandmicroreactiontechnology

• Modelling the dynamic behaviour of molecules in limited geometry

• Designofmethodologiesinlowfield-NMR

• Parameter imaging of disease-related degradation in cartilage and investigations of its biopolymeric compounds


Siegfried Stapf

Telefon +49 3677 69-3671

Telefax +49 3677 69-3205

siegfried�stapf@tu-ilmenau�de


Naturwissenschaften

TU Ilmenau

Unterpörlitzer Straße 38

Gebäude V, Raum 212

98693 Ilmenau

www�tu-ilmenau�de/techphys2

80



Internet

Research Topics

Contact

EducationTeaching on the bachelor level includes the full spectrum of classes, tutorials and computer labs in theoretical and computational physics. Research-based classes for master students and PhD candidates focus on solid state physics, optics, material science, statistical physics as well as numeri-cal methods and algorithms.

GroupBesides pursuing research as l’art pour l’art, the members of the group enjoy the interaction with experimental physi-cists and engineers in Ilmenau and elsewhere. They suggest experiments, predict their outcome and help in the inter-pretation of unexpected results. Most research activities are related to the study of the light-matter interaction. ResearchA variety of analytical and numerical methods are applied to a wide range of problems taken mostly from solid state physics, nanooptics, nanostructure physics and material science. Recent publications address the exciton-plasmon coupling in hybrid systems of organic or anorganic semicon-ductors, second-harmonic generation in transparent oxides, charge and energy transport in organic materials for pho-tovoltaic applications, ionic liquids, and near-field optical energy transfer. They result from close collaborations with researchers in Ireland, Japan, Korea, Sweden, the USA and several German groups. Further research interests are the development of a theory of attosecond electron emission in strong laser fields, statistical properties of disordered sys-tems and optimization in high-dimensional spaces.

Theoretical Physics ITheoretische Physik

• Semiconductor physics

• Plasmonics

• Ultrafast nanooptics

• Many-particle theory

• Modelling and simulation

• Computer-aided physics

• Material physics

• Theory of nanostructures

• Disordered systems

• Quantum chemistry

• Energy research and photovoltaics


Erich Runge

Telefon +49 3677 69-3707

Telefax +49 3677 69-3271

erich�runge@tu-ilmenau�de


Naturwissenschaften

TU Ilmenau

Weimarer Straße 25

Curiebau, Raum 320

98693 Ilmenau

www�tu-ilmenau�de/theophys1

Illustration of linear and nonlinear light-matter interaction with plasmons in disordered metal islands and excitons in a semiconductor quantum well structure.

81



Internet

Contact

Research Topics

Theoretical Physics II / Computational Physics Theoretische Physik II / Computational Physics

Professor Martina Hentschel joined the Ilmenau University of Technology in April 2012 as head of the group Theoretical Physics II/Computational Physic. In June 2012, the group be-came member of the Institute of Micro- and Nanotechnolo-gies. The group of Prof. M. Hentschel is particularly interested in mesoscopic systems. With sizes typically in the micrometer range, mesoscopic systems such as quantum dots, optical microcavities, or graphene are too big for a full quantum mechanical description, yet small enough to see quantum si-gnatures in the form of interference effects. In this sense and because of the typical length scales, their place is in between the microscopic and the macroscopic world (Greek meso: in between).Interference effects are a typical sign of quantum and wave phenomena, respectively. Examples include quantum trans-port phenomena and many-body effects in electronic micro-systems (such as Fermi-edge singularities or the Kondo effect in quantum dots of different geometric shape studied in the group), and also deviations from the ray picture in form of the Goos-Hänchen effect and the so-called Fresnel filtering (see figure).The latter lead to corrections of the well-known laws of re-flection and refraction and destroy the principle of ray-path-reversibility.Their implications are already visible in nowadays microopti-

cal devices, and will become more relevant as the system size is further reduced and the curvature dependence of these correction becomes important.Furthermore, the group is interested in applications of mi-crolasers, where miniaturization requires new approaches to ensure the characteristic directional light emission that is essential for their functionality. Here ideas from quantum chaos and the principle of ray-wave correspondence are very useful. The research of the Computational Physics group has strong links to other active groups of the Institute for Micro- and Nanotechnologies, in particular to the groups of Prof. J. Kröger (Experimental Physics I), Prof. S. Sinzinger (Technische Optik), and Prof. M. Hoffmann (Micromechanilca Systems). Here joint activities on the interface between miniaturized and microoptics are ongoing. Prof. M. Hentschel is leader of the Emmy-Noether-Research Group “Many-body effects in mesoscopic systems” funded by the DFG.

Prof. Dr.

Martina Hentschel

Telefon +49 3677 69-3612

Telefax +49 3677 69-3271

martina�hentschel@tu-ilmenau�de


Naturwissenschaften

TU Ilmenau

Weimarer Straße 25

Curiebau, Raum 308

98693 Ilmenau

http://www�tu-ilmenau�de/theophys2

Semiclassical corrections in near-critical total internal reflection

• Numerical simulations

• Mesoscopic systems

• Optical microcavities, graphene, quantum dots

• Many-body effects in the mesoscopic regime

• Microlaser with directional emission

• Semiclassical corrections to the ray picture

• Quantum chaos and complex wave phenomena

82



Internet

Research Topics

Contact

Three-Dimensional NanostructuringDreidimensionale Nanostrukturierung

GroupThe group “Three-Dimensional Nanostructuring” is engaged on research topics concerning scalable functional nanostruc-tures (especially of three-dimensional nanostructures) and nano-patterns, with motivations on the realization of the next generation of applicable highly efficient nano-devices and systems.

ResearchNano systems or devices built from three-dimensional (3D) nanostructures offer a number of advantages over those based on two-dimensional (2D) surface nano-patterns, such as large surface area to enhance the sensitivity of sensors, to collect more sunlight to improve the efficiency of solar cells or fuels, and to supply higher density emitters for increased resolution in flat panel displays. Therefore, the realization of different kinds of scalable three-dimensional nanostructu-res on substrates is a very important challenge topic within the nanotechnology research field. Our group that is mainly funded by BMBF ZIK-II and ERC are responsible for adapting scalable template techniques that combine with advanced equipments (e.g., Atomic layer deposition, Chemical vapor deposition, Physical vapor deposition and Electrochemical deposition) to fabricate and integrate different novel three-dimensional structures. There are three major surface-patterning templates derived

from self-assembly processes: ultra-thin alumina membra-nes (UTAMs), monolayer polystyrene (PS) sphere arrays, and block copolymer (BCP) patterns. The feature size of the sur-face structures prepared using BCP, UTAM, and PS templates can be adjusted within the range of about 5-50 nm, 5-500 nm, and 50 nm-4.5 µm, respectively, which covers a range from quantum size to nanometer size and micrometer size. Especially, the UTAM surface patterning technique provides an efficient approach to prepare large-scale ordered surface nano-patterns with well-defined structures, which provide an efficient way for 3D nanostructuring. The UTAM and PS nano-patterning methods are main surface nano-structuring techniques in our group for 3D nanostructuring process. Vari-ous interesting device-related properties, such as gas sensing, super-capacity, solar fuels and surface enhanced Raman spec-troscopy are investigated. Additionally, appropriate simulation methods (e.g., First Principle and Finite-difference time-do-main) are utilized for better understanding and optimizing of the electronic and optical properties of semiconductor nano-devices.

EducationThe group “Three-Dimensional Nanostructuring” is actively participating in teaching of the cutting-edge knowledge and the advanced equipments. Lectures, practical courses and the-ses are given for bachelor, master and PhD students in materi-al physics as well as in nanostructure physics.

Univ.-Prof. Dr.

Yong Lei

Telefon +49 3677 69-3748

Telefax +49 3677 69-3746

yong�lei@tu-ilmenau�de

Fakultät für Mathematik und Natur-

wissenschaften

TU Ilmenau

Prof�-Schmidt-Straße 26

Heliosbau, Raum H 1102

98684 Ilmenau

www�tu-ilmenau�de/nanostruk

• Functional three-dimensional nanostructure design, fabrication and integration

• Semiconductor and metallic materials synthesis based on template surface nano-patterning techniques

• Large-scale addressable nano-optoelectronic and memory devices and systems

• Novel solar fuels, energy storages, and sensing devices based on functional nanostructures�

• Simulation and evaluation of nano-devices and systems

e are at the very beginning of time for the human race� It is not unreasonable that we grapple with problems� But there are tens of thousands of years in the future� Our responsibility is to do what we can, learn what

we can, improve the solutions, and pass them on�

Richard P� Feynman

W

85

Research Activities

Basic Research & Material Science ��86

Process Technology ��120

Design & Simulation ��141

Devices ��150

Systems Integration & Applications ��168

Scientific Publications ��182

Journal Articles �� 182

Books / Book chapters �� 199

Conference Proceedings �� 199

Patents �� 204

Venia Legendi & PhD / Doctorate Theses�� 204

85

Nano-Biosystems Engineering Group

Funding: BMBF 16SV5473, TMK/TMWAI B71409064,

MacroNano® FKZ 03Z1M511

Patrick Mai | +49 3677 69-3367 | patrick�mai@tu-ilmenau�de

[1] R� Rylander, Scandinavian Journal of Work, Environment & Health, 1994, 20, 116-122�

[2] RR. Jacobs, American Journal of Industrial Medicin, 1994 25(1), 3-11.

[3] W. Eduard et al., Journal of Environmental Monitoring, 2012, 14(2), 334-339.

[4] S. Samadi et al., Annals of Agricultural and Environmental Medicine, 2013, 20(2), 206-221

Airways are in constant contact to ambient air. Aspiration of harmful substances in domestic or industrial environment can lead to acute or chronic diseases of the lung [1]. These diseases belong to the leading causes of death worldwide. A special position in this issue is taken by bioaerosols. Bioaerosols are airborne particles with a biological origin (animals, plants, insects and microbes) [2, 3]. While these aerosols occur in a heterogenic mixture of different biological particles the evaluation of epidemiological studies and risk assessments is difficult [3, 4].To investigate the biological effects of bioaerosols in the lungs, a 3D-co-culture consisting of alveolar epithelia cells and capillary endothelia cells was established. A PC-Foil (MatriGrid) with imprinted cavities is used as a cell carrier. The shape of the cavities correspond roughly to the proportions of the alveoli (fig. 1 A). The enabling of culturing the cells on an air-liquid interface (ALI), which equals the in-vivo situation (fig. 1 B), is the second benefit. In-vivo only the lung endothelia cells are surrounded by blood, while the epithelia cells are exposed to the air. First experiments with this model have shown the possibility to investigate the biological effects by measuring inflammatory

cytokines (interleukin-8) in the supernatant after exposure to lipopolysaccharide (LPS) (see fig. 2)Future investigations concern the development of an exposure system under the aspects of constant bioaerosol production and distribution on the cells. Therefor, it is based on normal 24-well microtiter plates (MTP) in which the 3D-co-culture is cultured till the exposure experiments start. After bioaerosol generation by use of a commercial nebuliser (Pari LC Sprint®), the bioaerosol is distributed through tubings and a manifold. One manifold is designed for four wells and connect the tubing with a nozzle for each well. This nozzle leads the bioaerosol in close contact to the cells and a special sealing guarentees the tightness of the system. Several manifolds can be used on one MTP to compare exposed and unexposed cells within the same set of samples. Besides the better bioaerosol distribution this exposure system enables the use of standard culture methods for MTPs instead of time consuming induction of new culture methods.With the presented 3D-co-culture and exposure system, we introduce a novel platform for the assessment of cytotoxic effects of bioaerosols to the lung.

P. Mai, U. Fernekorn, J. Hampl, A. Schober

3D-co-culture model of the lung and bioreactor for exposure experiments with bioaerosols

Fig. 2: Measurement of IL-8 in the supernatant of the 3D-Co-Culture after LPS exposure at different times

Fig. 1: A) Comparison of the alveolus and the MatriGrid cavities, B) Principe of ALI-Culture

Contact


86

BASIC RESEARCH & MATERIAL SCIENCE



Contact

87

Uwe Ritter | +49 3677 69-3603 | uwe�ritter@tu-ilmenau�de

[1] N�G� Tsierkezos, U� Ritter, J� Solid State Electrochem� 2012, 16, 2217

[2] N�G� Tsierkezos, P� Szroeder, U� Ritter, Microchim� Acta 2014, 181, 329

[3] N� Tsierkezos, A� Knauer, U� Ritter, Electrocatalysis 2014, 5, 87

The aim of this work was the fabrication of nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs), their modification with gold nanoparticles (AuNPs) with different diameters (5, 14, and 35 nm), and their application in sensing [1,2]. The electrochemical responses of N-MWCNTs/AuNPs towards simultaneous analysis of dopamine (DA) and uric acid (UA) in presence of ascorbic acid (AA) were studied in phosphate buffer solution (pH 7.0).The findings exhibit that the diameter of AuNPs plays an essential role for improvement of film’s electrochemical response. An enhancement of electrocatalytic activity of N-MWCNTs/AuNPs (14 nm) towards simultaneous oxidation of DA and UA was recognized in presence of AA. Specifically, on N-MWCNTs/AuNPs (14 nm) greater peak potential separation between DA-UA was identified (~250 mV), as compared to that on composite films decorated with AuNPs having diameter of either 5 nm (~230 mV) or 35 nm (~210 mV). In addition, the separation between AA-DA oxidation waves, which is greater compared to that between DA-UA waves, increases progressively with the diameter of AuNPs. Thus, onto N-MWCNTs/AuNPs with AuNPs possessing diameters of 5, 14, and 35 nm peak separations of 280,

290, and 300 mV, respectively, were observed for AA-DA oxidation waves. The findings demonstrate that the interference of AA can be considered in all cases negligible. In addition, the results exhibit that on N-MWCNTs/AuNPs (14 nm) large separation between DA-UA oxidation waves occurs permitting the simultaneous analysis of DA and UA in a single measurement. It is quite interesting that on this particular film, DA can be detected in the presence of an excess of UA, and similarly, UA can be analysed in an excess of DA. Furthermore, the findings demonstrate that the interfering effect of AA in simultaneous oxidation of DA and UA on N-MWCNTs/AuNPs (14 nm) is negligible.The lower detection limits of N-MWCNTs/AuNPs (14 nm) towards DA (0.011 μM) and UA (0.151 μM) are lower compared to those reported in literature for other novel films [3]. The findings suggest the potential application of N-MWCNTs/AuNPs (14 nm) film for sensing of DA and UA in a single experiment.Real urine samples were tested for simultaneous analysis of DA and UA on N-MWCNTs/AuNPs by means of standard addition technique. The recovery tests (96-101%) indicated that no matrix effects can be observed.

N. Tsierkezos, U. Ritter

Carbon nanotubes decorated with gold nanoparticles in sensing

Fig. 2: DPVs recorded for AA/DA/UA (1:1:1) on N-MWCNTs/AuNPs (a: 5 nm; b: 14 nm; c: 35 nm)

Fig. 1: SEM micrograph of N-MWCNTs/AuNPs (14 nm)

Group of Chemistry

Group for Physical Chemistry / Microreaction Technology

Funding: Carl-Zeiss-Stiftung

Claudia Lenk | +49 3677 69-3657 | claudia�lenk@tu-ilmenau�de

[1] A. N. Zaikin, A. M. Zhabotinsky, Nature 225, 535 (1970).

[2] K. Suzuki, T. Yoshinobu, H. Iwasaki, J. Phys. Chem. A 104, 5154 (2000).

Spatial obstacles and coupling of oscillators strongly influence the pattern formation in different areas such as, e.g., chemical reactions, the propagation of electrical excitations in the heart, population or plankton dynamics, as well as the spreading of forest fires. Fibrillation, e.g., can be the result of decoupling of cells in the heart. To study the influence of the spatial system structure and the coupling of oscillators in the Belousov-Zhabotinsky reaction (BZR) [1], stable and reproducible catalyst distributions (Fig. 1) are required, which are typically generated by photolithography [2] or emulsions. A simpler way is to plot the catalyst onto a silica gel matrix with the Nanoplotter NP 1.2 from GeSIM.We investigated if the addition of polymers into the silica gel can enhance the immobilisation of Ferroin, a standard catalyst for the BZR. Polyethylenglycol (PEG), poly-styrene sodium sulfate (PSSS) and poly-styrenesulfate-co-macleic acid) sodium salt (PSS-Co-PM) were tested. The polymers were added to a sodium- metasilicate solution before the addition

of sulphuric acid. The stability of Ferroin spots was analysed by optical measurements. PEG and PSS-Co-PM increased the immobilisation time from only minutes to several days whereas PSSS had no effect. The microstructure and chemical composition of the gels were investigated by scanning electron microscopy (Fig. 2) and energy dispersive X-Ray spectroscopy (EDX). Thereby, an altered microstructure was only observed for gels with PEG, whereas only for PSS-Co-PM an incorporation of the polymer in the gel could be concluded from a significant carbon signal in the EDX spectra. We determined the decomposition rate of Ferroin in metasilicate solution in the presence of one of the polymers by UV-VIS spectroscopy to test an interaction between Ferroin and the polymer. A reduced decomposition rate was only observed for PSSS and PSS-Co-PM. An improved immobilisation of Feroin did thus result either from microstructural changes due to PEG addition or the incorporation of PSS-Co-PM into the gel and its interaction with Ferroin.

C. Lenk, J. M. Köhler

Chemical Modification of Silica Gels for Ferroin Immobilisation

Fig. 2: SEM images of silica gels: upper left-pure gel, upper right-with PEG, lower left-with PSS-Co-PM and lower right-with PSSS

Fig. 1: Ferroin Spotarray (red) on Silica Gel (white) with propagating chemical waves (light blue) due to Belousov Zhabotinsky Reaction


Contact


88

Fig. 2: Images of a calibration sample at a scan rate of 15 lines/s and Q factors as indicated.

Fig. 1: (a)-(c) indicates the modified Q factors in different eigenmodes, (d) modified resonance frequ. of the first eigenmode.



89

Contact

Funding: Masdar Institute, FP7 „PRONANO“,

ZIM-Projects: KF2563104NT2 & KF2114205

1 Massachusetts Inst. of Technology, MECHE2 Micro- and Nanoelectronic Systems Group

Andreas Schuh | +49 3677 69-1589 | andreas�schuh@tu-ilmenau�de

[1] T� Sulchek, R� Hsieh, J� D� Adams, G� G� Yaralioglu, S� C� Minne, C� F� Quate, J� P� Cleveland, A� Atalar, and D� M� Adderton�

Applied Physics Letters, 76:1473, 2000�

[2] Robert W. Stark, Tanja Drobek, and Wolfgang M. Heckl. Applied Physics Letters, 74(22):3296, 1999.

[3] Tomas R. Rodriguez and Ricardo Garcia. Applied Physics Letters, 82(26):4821, 2003.

[4] R. Pedrak, Tzv Ivanov, K. Ivanova, T. Gotszalk, N. Abedinov, I. W. Rangelow, K. Edinger, E. Tomerov, T. Schenkel, and P.

Hudek. JVST B, 21(6):3102, 2003.

IntroductionHigh Speed Atomic Force Microscopy (AFM) is of great interest towards the real-time observation of processes and large scan areas, such as cell dynamics or inspection of semiconductor wafers. However, a major bottleneck in the topography feedback loop of AFMs is the cantilever probe itself [1]. The effective Q factor and natural frequency in the presence of a sample surface form an imaging time constant of τi=〖2Q〗(eff,i)/ω(eff,i) in each eigenmode i. Hence, using higher cantilever eigenmodes can increase the imaging bandwidth considerably [2]. Alternatively, the Q factor could be lowered to increase the bandwidth, with the cost of higher forces exerted onto the sample surface [3]. In this work, active Q control is combined with the fast imaging capability of higher eigenmodes. The discussed compensator can be easily attached to existing AFMs and allows for flexible tuning of the imaging rates. The setup is tested in combination with active cantilevers that integrate both actuator and sensor [4].CompensatorThe developed compensator allows to modify the cantilever dynamics such that the Qi factor and ω(n,i) of each eigenmode can be set to desired values. Each eigenmode is approximated by a second order transfer function, acquired

by an automatic system identification approach. As the velocity proportional signal of the cantilever vibration is not measured, it is determined through an estimator operated in real-time and in parallel to the cantilever. A controller uses the estimated signals and modifies the cantilever dynamics. The discretized compensator is integrated into a Xilinx Spartan-3A DSP with connected 100 MHz ADCs and DACs. The internal compensator feedback loop rate is 3.57 MHz. This allows scanning at higher eigenmodes up to the MHz range.ResultThe cantilever Qi is modified up to the third eigenmode and used for scanning a sample structure. Figure 1 indicates the three resonances with different Q factors: Q1=10, 60, 120, Q2=120, 148, 291 and Q3=120, 210, 757. Also in the same Figure, (d) shows a modification of the resonance frequency of the first eigenmode. Figure 2 is a scan of a calibration sample (Anfatec UMG03/PtS) that has 2 μm wide and 58 nm high parallel SiO2 lines on a silicon substrate with a pitch of 4 µm at a scan rate of 15 lines/s. Here, the first eigenmode is used and modified as indicated. The tracking issues at the higher Q are clearly visible, as expected by the lower bandwidth.

A. Schuh1,2, I. S. Bozchalooi1, K. Youcef-Toumi1,

I. W. Rangelow2,

Control of Higher Cantilever Eigenmodes for High Speed Atomic Force Microscopy

Fig. 2: Micro fabricated sensor housing.Fig. 1: Two chamber setup for membrane ion permeability testing.


Contact


90

1 Micromechanical Systems Group2 Biomechatronics Group3 Nano-Biosytems Engineering Group

Funding: BMBF:Wachstumskern BASIS, FKZ: 03WKCB010

Stefan Hanitsch | +49 3677-69-3424 | stefan�hanitsch@tu-ilmenau�de

[1] D. Buenger et al., „Hydrogels in sensing applications“, Progress in Polymer Science 37 (2012) 1678–1719.

[2] Hanitsch, S�; Hoffmann, M�; „Test Environment for Hydrogels as Functional Sensor Window”, Proceedings BMT, 2013, 47�

DGBMT Jahrestagung, Graz�

IntroductionFor the creation of an appropriate sensor interface for electrochemical biosensors, hydrogel membranes show interesting properties [1]. They are mostly biocompatible and can be loaded or functionalized. Porous membranes can be used to separate the analyte from complex samples such as biological samples and to protect the sensor from abrasive particles and biofilm formation. But, protective membranes as sensor interfaces add an additional time delay to the system. To evaluate sensing characteristics of such membranes, a test setup with a diffusion chamber was created [2]. SetupTwo cylindrical chambers of 1cm³ each are separated by the membrane to be tested and perfused in different circulations. Figure 1 shows a schematic cross section of the setup. For the testing, a step in conductivity is induced by the perfusion of one chamber with concentrated potassium chloride solution. The setup is equipped with two peristaltic pumps and allows different measurement regimes. According to

the pumping regime static concentration measurements, quasi static or dynamic measurements can be performed. The conductivity in the second chamber is monitored by an external conductivity meter. Alternatively, the second chamber can be replaced by a micro fabricated sensor housing containing a model sensor to mimic the sensor behavior in later applications and to test hydrogel patches. The sensor housing was produced by Low Temperature Co-fired Ceramics technology and can be integrated into the test setup via integrated microfluidic channels. Figure 2 shows the sensor housing.ResultsSeveral classes of hydrogel films and porous polymer foils with thicknesses around 200 μm were tested under dynamic conditions and could therefore be evaluated according to their ion permeability and time delay. Degradable bio hydrogels such as polylactide based gels appeared to have low time constants of about 30min while stable hydrogel membranes reached approximately 60% of equilibrium after several hours.

S. Hanitsch1, M. Stubenrauch2, J. Tobola3, H. Witte2, A.

Schober3, M. Hoffmann1

Diffusion Chamber for Hydrogel Membrane Testing

Fig. 1: (a) CVs of UA (0.166-0.681 mM) in presence of DA (0.117 mM) on MWCNTs/PET; (b) Oxidation current of UA versus its concentration



91

Contact

Funding: BMBF Project CarboSens (16SV5326)

Uwe Ritter | +49 3677 69-3603 | uwe�ritter@tu-ilmenau�de

[1] N.G. Tsierkezos, N. Wetzold, A.C. Hübler, U. Ritter, Sensor Letters 2013, 11, 596

[2] N�G� Tsierkezos, N� Wetzold, U� Ritter, Ionics 2013, 19, 335

[3] N.G. Tsierkezos, U. Ritter, N. Wetzold, A.C. Hübler, Analytical Letters 2014 (accepted)

The mass flexographic printing process (MFPP) is simple and effective method that can be applied for fabrication of disposable films for electrochemical sensing in broad areas of nanotechnology. MFPP is preferred over conventional methods for producing sensors since is inexpensive, rapid, and productive. Films consisting of multi-walled carbon nanotubes (MWCNTs) and conducting polymers fabricated by means of MFPP represent new sort of electrodes that combine the excellent mechanical and electrical properties of MWCNTs with the good flexibility, high transparency, high capacitance, easy processing, and low cost of polymers. Thus, the goal of this research work is the combination ofto combine MWCNTs and polymers for the production of simple, stable, sensitive, low-priced, and disposable sensors. For this purpose MWCNTs/polymer films were fabricated through transfer of water-dispersed nanotubes onto polyethylene terephthalate polymer substance by means of MFPP [1,2]. The printed film, further denoted as MWCNTs/PET, was initially electrochemically characterized using the redox system ferrocyanide/ferricyanide, [Fe(CN)6]

3-/4- in potassium chloride solution. The findings exhibit an enhanced charge-transfer kinetics of [Fe(CN)6]

3-/4- on MWCNTs/PET, and thus, the investigated redox system can be characterized as reversible on this particular film. The detection limit of MWCNTs/PET towards [Fe(CN)6]

3-/4- (3.1 µM) is significantly smaller compared to that of other sensors reported in literature. This finding demonstrates the excellent electrochemical quality of MWCNTs/PET.The possibility of using MWCNTs/PET for detecting redox systems with biological interest was studied. For this purpose the electrochemical response of MWCNTs/PET towards oxidation of acetaminophen (AC), dopamine (DA), and uric acid (UA) was investigated in phosphate buffer solution (pH 7.0). The lower limit of detection of MWCNTs/PET towards AC (3.9 µM), DA (5.0 µM), and UA (4.1 µM) appears to be smaller when compared to those of other sensors reported in literature [3].

Interference studies reveal that DA and UA can be analyzed simultaneously on MWCNTs/PET since their voltammetric waves are not overlapped (they do not interference with each other). Specifically, the separation between the oxidation waves of DA-UA (140 mV) is sufficiently large to permit the determination of DA and UA in a single measurement (Figure 1). The results strongly suggest the possibility of using disposable MWCNTs/PET films for routine analysis in electrochemical sensing. The precision of printed films was evaluated by means of cyclic voltammetry. The method’s reproducibility was studied by measuring the response of five films towards AC, DA, and UA. In all cases, reproducibility of less than 2.5% was estimated. Furthermore, the method’s repeatability was studied by monitoring the current response of the same film towards studied biomolecules for ten different successive measurements. The repeatability of less than 3.5% estimated for MWCNTs/PET was quite acceptable. The findings demonstrate that the novel printed MWCNTs/PET films have quite good repeatability and reproducibility towards the investigated redox systems.

N. Tsierkezos, U. Ritter, N. Wetzold

Disposable multi-walled carbon nanotubes printed films

Fig. 1: Diagram of the sample setup with magnetic field (B0) and gradient (G0) directions being indicated by arrows.


Contact


92

Siegfried Stapf | +49 3677 69-3671 | siegfried�stapf@tu-ilmenau�de

[1] S. Ghoshal, C. Mattea, L. Du, and S. Stapf, Concentration and Humidity Effect on Gelatin Films Studied by NMR, Z. Phys.

Chem. 226, 1259 (2012).

[2] C. Mattea, S. Ghoshal, E. Pabianczyk and S. Stapf, Poly(vinyl alcohol)Film Formation Process Using Single-Sided Low-Field

NMR Relaxometry: Effect of Initial Concentration, Microporous & Mesoporous Materials, 178, 27, (2013).

[3] S. Ghoshal, S. Stapf and C. Mattea. Protein renaturation in the gelatin film formation process. Appl. Magn. Reson., 45,

145 (2014).

Investigations of the molecular dynamics during the drying of polymer solutions in their process of film formation are performed in order to correlate the final dynamical and structural properties of the films, with the evaporation process.

The drying process can be monitored in real-time using spatially resolved NMR, with a sensor particularly designed for scanning flat 2D objects with an open geometry. Theseis kinds of devices work at low magnetic fields strengths (smaller than conventionally used high fields), and allow the measurement of typical NMR parameters like relaxation times and diffusion. With these parameters one obtains information about the dynamical properties of the samples under study.

Funding: Deutscher Akademischer Austauschdienst DAAD

Group of Technical Physics II / Polymer Physics

S. Ghoshal, C. Mattea

Dynamics during film formation in Polymer/Biopolymer-films using NMR

In particular, studies of drying of biopolymers involving gelatin and starch [1], as well as drying of water soluble polymers like PVA [2], were performed. The applied NMR technique allows depth-dependent determination of relaxation times, which gives information of the molecular mobility across the film, obtaining direct quantitative insight into the drying processes.

A study of starch film formation is currently performed, showing the evolution from the initial polymer suspension (starting from a dilute system) or gel (starting from a concentrated system) to the final film, in order to get insights into the film development of this biopolymer.

The result of these studies shows several features, like heterogeneities during film formation, and a correlation with the persistent structural heterogeneities in the final films. Moreover, the renaturation of collagen protein in gelatine solutions during drying, could be associated with the dynamical heterogeneities in the film formation [3].

The device used for these kinds of experiments, called single-sided NMR sensor, provides a tool for real-time monitoring of film formation processes from solution in a number of other systems, and allows, keeping the industrial importance of such films and in particular those made from biodegradable polymers, in mind, the manipulation of the production processes.



93

Contact

Micromechanical Systems Group

Funding: Bundesministerium für Bildung und Forschung,

Wachstumskern BASIS, FKZ: 03WKCB010

Stefan Hanitsch | +49 3677-69-3424 | stefan�hanitsch@tu-ilmenau�de

[1] Barnerjee et al., “Antifouling Coatings: Recent Developments in the Design of Surfaces That Prevent Fouling by Proteins,

Bacteria, and Marine Organisms“, Adv. Mater. 2011, 23, 690–718.

[2] Ekblad et al.,” Poly(ethylene glycol)-Containing Hydrogel Surfaces for Antifouling Applications in Marine and Freshwater

Environments“, Biomacromolecules 2008, 9, 2775–2783.

[3] Hanitsch et al�, “Method for Testing of Hydrogel Sensor Coatings”, Proceedings BMT 2014, 48� Jahrestagung DGBMT, Hannover�

IntroductionWhy biosensors fail and how failure can be prevented is one of the key-questions the “Wachstumskern BASIS” project is working on. The main threat for failure of sensor electrodes is the formation of a biofilm. Biofilms are produced by different kinds of bacteria as a part of their extracellular hydrogel matrix. One way to protect sensor electrodes in micro-biological highly active environments is the use of biofilm repellent coatings[1]. A hydrogel sensor coating may work as an artificial biofilm with defined properties. The coatings can be loaded with antibiotics or can be tailored towards repelled surface properties[2]. To test specially designed hydrogel coatings for sensor protective purposes, a universal test platform is proposed: A Bio-TestChip[3].Requirements for a BioTestChipAs the sensor coating should be used for biomedical applications, the coating needed to be examined according to its biocompatibility. To facilitate the standard methods (conducted at the Iba in Heilbad Heiligenstadt), the chip itself had to be biocompatible, and it had to fit into a standard 24-well cell culture dish and into other existing equipment. Further, a test sensor functionality had to be implemented and electrically connected. This was needed for the evaluation of the signal transmission of the coating. For a screening of different hydrogels, a significant number of chips had to be manufactured.Chip Fabrication and MaterialsMedical grade zirconia ceramics were chosen as a substrate for the BioTestChips. Our project partner Moje-Implantate GmbH & Co. KG provided 15mm chips with two predrilled vias. For the creation of a simple test sensor setup, interdigital electrodes were screen printed onto the ceramics. An Ag co-fire paste from Dupont© was used. The screen printing was parallelized using a lasercut stainless steel holder which was brought into the screen printer to enable the processing of twelve chips at a time. On the back side of the chips, contact patches were mounted. These were connected to the front

side by drill holes in the ceramic substrate filled with a low-shrinkage via-filler paste also provided by Dupont©. The screen printed pastes were fired according to the datasheet.TestingAll tested hydrogel coatings were new formulations provided by our project partner Innovent e.V. The coating was applied by dip- or spincoating with a pretreatment according to the hydrogel in test. The coated chips were steam sterilized and tested in a cell culture assay for bio compatibility and biofouling. Afterwards, the chips were inspected by microscopy. The test of signal transmission was done in a perfusion-chamber filled with potassium chloride solution at different concentrations. The sensor chip was used to measure the conductivity within the chamber. Obtained values were compared to uncoated sensor chips.ResultsThe fabricated bio test chips are a suitable model for an implantable sensor and enable a multi-parameter screening of sensor coatings for applications in implantology. They can be used to examine coating technologies, sterilizability, biocompatibility, antifouling behavior and signal transduction. From the tested hydrogel coatings, chitosan based hydrogels showed the best results in terms of antifouling properties and signal transduction.

S. Hanitsch, M. Hoffmann

Fighting Biofouling – Hydrogel Sensor Coating Screening with BioTestChips

Fig. 1: Bio Test Chip for hydrogel sensor coating evaluation

Plastics Technologies Group

Funding: KF2184727CK2 Zentrales Innovationsprogramm

Mittelstannd (ZIM) des Bundesministerium für Wirtschaft und

Energie (BMWi)

Matthias Bruchmüller | +49 3677 69-1966 | [email protected]

[1] J. Geis, Untersuchung des Gleitverhaltens von Kunststoffoberflächen auf Sand (2013)

IntroductionPhysical movement is often accompanied by friction, which implies a loss of kinetic energy and resultant wear. The improvement of tribology reduces friction losses and enhances the energy balance of movement. Main influencing parameters on friction are the material parameters and the contact surface. [1] In this study, a method for the calculation of tribological properties, based on material properties is developed in order to find a suitable plastic compound for use on sand. In this work it could be found that there is a correlation between mechanical and tribological parameters resulting in the possibility of calculating performance on sand based on filled compound.ExperimentsThe specimens are compounds of polyamide 6.6 and seven fillers, like short carbon fibers, PTFE or talcum particles. The compounds are produced by a co-rotating twin-screw extruder with a screw diameter of 40 mm and an L/D of 38. Afterwards, an injection molding machine injects the compound into a mold and forms the specimen. The filler

contents of specimen are varied and combinations of fillers are examined. The experiment involves tribological measurements, material and surface properties like hardness, strength, strain, elongation and roughness. All mechanical testing was conducted at temperatures from 20-60°C. ResultsBased on the results, a multi linear regression is applied to obtain an equation, which describes the correlation between mechanical and tribological parameters by specific linearized values. For the verification of the equation, a correlation factor R² is derived describing the reliability of the formula. The correlation with the output "friction coefficient" offer a dependency by median roughness, tensile strength and temperature by a correlation factor of 83,35 % (figure 1). For the given abrasion rate, not only did the tensile strength have an influence by a correlation factor of 85,70% (figure 2), but also the yield modulus, ball hardness and elongation at break. Based on this model a compound with improved tribological properties is theoretically derived, produced and successfully tested.

M. Bruchmueller, M. Koch

Friction upon Sand - Tribological Improvements of Plastic Compounds

Fig. 2: Comparison of calculated and measured abrasion ratesFig. 1: Comparison of calculated and measured friction coefficients


Contact


94



95

Contact

1 Group of Materials for Electrical Engeinnering and

Electronics2 Laboratoire des Multimateriaux et Interfaces, UCB Lyon3 Nanotechnology Group

Jörg Pezoldt | +49 3677 69-3412 | joerg�pezoldt@tu-ilmenau�de

[1] E.N. Kalabukova, S.N. Lukin, B.D. Shanina, E.N. Mokhov, Sov. Phys. Solid State 32, 465 (1990).

[2] K� Alassaad, V� Souliere, F� Cauwet, H� Peyre, D� Carole, P� Kwasnicki, S� Juilliguet, T� Kups, J� Pezoldt, G� Ferro, Acta

Materialia 75, 219 (2014)

[3] T. Kups, M. Voelskow, W. Skorupa, M. Soueidan, G. Ferro, J. Pezoldt, Springer Proc. Phys. 120, 353 (2007)

Impurity incorporation allows tuning of the properties of semiconductor materials. Depending on the concentration and the type of the incorporated impurities, the carrier concentration, the absorption coefficient, the lattice constant and band structure can be changed. The last effect can be achieved by forming solid solutions. By combining materials with different band structures and similar lattice constants, heterostructures can be fabricated allowing for the manufacture of advanced electronic, optoelectronic and sensor devices.In the case of silicon carbide (SiC), the incorporation of foreign atoms has been studied for group II, III and V impurities to achieve p- and n-type doping. Doping with other impurities like vanadium was also investigated in order to achieve highly resistive or semi-insulating SiC. Up to now, less attention has been paid to the role of group IV elements in SiC. These elements belong to the group of isoelectronic impurities and exhibit a relatively high solid solubility. In [6] it was shown that Ge may change the incorporation and the lattice site location of nitrogen. Furthermore, the doping of silicon carbide increases the conductivity and the carrier concentration and reduces the contact resisitivity. For

this reason it is important to know the lattice location of germanium in silicon carbide.The 4H-SiC epitaxial layers were grown by chemical vapour deposition using propane and silane as a carbon and silicon source. The growth temperature was varied between 1450°C and 1600°C. The growth rate and the C/Si ratio were varied from 2.3 to 6 μm/h and from 2 to 8, respectively. The germanium doping of the grown 4H- SiC epitaxial layers was realized by using germane as an germanium source. ALCHEMI (atomic location by channelling enhanced microanalysis) was used to determine the site occupancy of dopants in the SiC matrix. For the investigation of the lattice site occupation of Ge in SiC, the following algorithm was applied: measurement of tilt dependence of EDX signal, Bloch wave calculation of tilt dependence of the excitation of selected Bloch states and comparison of measured and simulated dependencies (Fig. 1 and 2). The carried out investigation revealed that Ge resides on silicon lattice sites in 4H-SiC [2]. A similar result was obtained for the lattice sit location of Ge in 3C-SiC grown by liquid phase epitaxy and molecular beam epitaxy [3].

T. Kups1, G. Ferro2, J. Pezoldt3

Germanium lattice location in 4H-SiC

Fig. 2: Ge signal evolution on a Ge doped sampleFig. 1: ALCHEMI simulation showing Bloch state excitation for different atomic sites normalized to the Si signal in SiC

Three-Dimensional Nanostructuring Group

Funding: BMBF (ZIK-3DNanoDevice: 03Z1MN11), European

Research Council (ThreeDsurface: 240144)

Yong Lei | +49 3677 69-3748 | yong�lei@tu-ilmenau�de

[1] M. Zhou, J. Bao, Y. Xu, J. Zhang, J. Xie, M. Guan, C. Wang, L. Wen, Y. Lei, Y. Xie, ACS Nano 8, 7088 (2014).

[2] Y. Mi, Z. Huang, F. Hu, Y. Li, J. Jiang, Journal of Physical Chemistry C 113, 20795 (2009).

[3] Y. Mi, M. Zhou, L. Wen, H. Zhao, Yong Lei, Dalton Transactions 43, 9549 (2014).

Since the discovery of photocatalytic splitting of water on TiO2 electrodes in 1972 by Honda and Fujishma, efficient utilization of solar energy for photocatalysis towards environmental purification and solar energy conversion have been attracting massive research interest. Various photocatalysts have been prepared and used in photocatalytic water splitting and photodegradation of organic pollutants [1]. However, the photocatalysis of many photocatalysts are limited under ultraviolet irradiation (λ < 380 nm), only 4% of solar light. Therefore, it is of great significance to develop visible-light driven photocatalysts for highly efficient solar utilization.Recently, bismuth oxyhalides (BiOX, X = Cl, Br, and I), a series of novel layered ternary oxide semiconductors, have received much attention. BiOX possess a layered structure, which is consisting of [Bi2O2]2+ slabs separated by double slabs of halogen atoms. The space of layered structures is large enough to increase for polarizing the related atoms and orbitals. The induced dipole could then improve the separation efficiency of hole-electron pairs, and thus the BiOX structure shows outstanding photocatalytic performances. Furthermore, bismuth oxyhalides can extend light absorption to visible light range (EgBiOI = 1.9eV). This is highly important for the direct use of sunlight. Meanwhile, the morphology structures also play important roles.

Profiting from high specific surface areas and large fraction of uncoordinated surface atoms, quasi-two-dimensional (quasi-2D) structure has a strong advantageous effect on photocatalytic performance [2]. However, quasi-2D nanostructure of BiOI has rarely been realized and reported.We report on the challenges of synthesizing 2D square-like BiOI nanosheets with thickness of about 10 nm and exposed {001} facets by a facile hydrothermal route without any surfactant and special solvent [3]. The photocatalytic performance of as-prepared 2D square-like BiOI nanosheets are evaluated by the photodegradation of rhodamine-B (RhB), methyl orange (MO) and phenol under visible-light irradiation. The products show highly efficient photocatalytic performance and good photostability and recyclability under the visible light irradiation. The efficient photocatalytic activity shall be ascribed to the exposed {001} facet of thin 2D square shape nanosheet, which provides appropriate diffusion length and self-induced internal static electric fields of BiOI and hence improves the separation efficiency of photoinduced electron-hole pairs in BiOI nanosheets. Furthermore, the thin nanosheets have more percentage of {001} facet exposure which could induce stronger internal static electric fields and improve the photocatalytic activity.

Y. Mi, M. Zhou, L. Y. Wen, Y. Lei

High Efficient Visible-Light Driven Photocatalyst: 2D Square-like Bismuth Oxyiodine Nanosheets

Fig. 2: 2D square-like BiOI nanosheet with exposure of {001} facets present high efficient visible-light photocatalytic activity

Fig. 1: Schematic representation of the crystal structure of BiOX. (a) BiOX; (b) {001} facet of BiOX; and (c) [Bi2O2]2+ layers


Contact


96

Fig. 1: (a) XPS N1s core level spectra and (b) schematic diagram of the surface band bending of N-polar InN before (black) and after (blue) hydrogen exposure.



97

Contact

Research Group Surface Physics of Functional Nanostructures

Funding: Deutsche Forschungsgemeinschaft under

grant Scha 435/25 and Carl-Zeiss-Stiftung

Anja Eisenhardt | +49 3677 69-4901 | anja�eisenhardt@tu-ilmenau�de

[1] Eisenhardt, A. et al. Appl. Phys. Lett. 102, 231602 (2013)

[2] Eisenhardt, A. et al. Phys. Status Solidi A 209, 45 (2012)

[3] Eisenhardt, A. et al. J. Appl. Phys. 115, 043716 (2014)

[4] Janotti, A. et al. Appl. Phys. Lett. 92, 032104 (2008)

IntroductionIn the last few years, our group has contributed to the understanding of intrinsic surface electronic properties of polar and nonpolar indium nitride (InN) [1]. Thereby, it was shown that electron accumulation, a property that was believed to be an universial feature of all InN surfaces, strongly depends on the surface orientation, which is characterized by specific surface reconstructions and surface states [1], as well as adsorbates interacting with the InN surface [2,3]. As-grown N-polar InN surfaces normally show a reduced electron accumulation that strongly increases during storage of the samples under ambient conditions [2]. Adsorption experiments have shown that oxygen can be ruled out as source for the electron accumulation [2]. However, hydrogen, an element that is predicted to significantly influence the electronic properties of InN [4], plays an important role, as will be demonstrated by the following results.ExperimentalN-polar InN films were grown by plasma-assisted molecular beam epitaxy on SiC(000-1) substrates with a thin GaN buffer layer, and in-situ characterized by photoelectron spectroscopy (XPS, UPS). Afterwards, the InN samples were exposed to atomic hydrogen at room temperature.ResultsHydrogen at N-polar InN surfaces mainly interacts with the N-atoms forming N-H or N-H2 bonds (Fig. 1(a)). Furthermore, adsorption of hydrogen on the N-polar InN surfaces results in a shift in the XPS core level binding energies of +0.3 eV. Simultaneously, the work function Φ of the InN samples decreases by 0.9 eV, leading to a surface dipole ΔΦdip of about -0.6 eV. The changes in the surface electronic properties of the InN sample can be interpreted as follows: hydrogen is bound to the topmost InN layer and thereby donates its electron to the surface. This leads to a significant increase in the surface electron concentration and surface downward band bending. The changes are illustrated in

Fig. 1(b). Consequently, hydrogen could be identified as one main source leading to the formation of an electron accumulation layer at N-polar InN surfaces.

A. Eisenhardt, M. Himmerlich, S. Krischok

Interaction of hydrogen with N-polar Indium Nitride surfaces

1 Laboratory of physics of nanostructures, Academic

University Saint Petersburg2 Nanotechnology Group Funding: DAAD


[1] V. Cimalla, J. Pezoldt, O. Ambacher, J. Appl. Phys. D: Appl. Phys. 40, 3386 (2007).

[2] A.A. Schmidt, K.L. Safonov, Yu.V. Trushin, V. Cimalla, O. Ambacher, J. Pezoldt, Phys. Status Solidi (a) 201, 333 (2004).

[3] R. Nader, F. Niebelschultz, D.V. Kulikov, V.S. Kharlamov, Yu. V. Trushin, P. Masri, J. Pezoldt, Phys. Status Solidi (c) 7, 141

(2010).

[4] M.N. Lubov, J. Pezoldt, Yu.V. Trushin, Mater. Sci. Forum 740-742, 393 (2013)

The growth of the silicon carbide (SiC) on silicon (Si) allows combining the benefits of SiC physical properties with the well-developed silicon technologies. The SiC/Si heterostructure could be used as substrate for graphene, III-nitrides epitaxy (GaN, AlN), as a material of sensors operating at high temperatures and microelectromechanical systems [1]. The main challenge in device processing with SiC/Si structure is the lattice and thermal mismatch between SiC and Si. As a result of a high mismatch, SiC grows on Si substrate via Volmer-Weber mechanism (3D SiC clusters form on Si substrate) [2]. Pre-deposition of impurities on Si substrate before growth is one of the possibilities for controlling the nucleation process of SiC clusters and thereby controlling the quality of the SiC/Si interface [3] and the wafer bow. A kinetic model of the SiC clusters' growth on Si substrate with the predeposited impurity was developed. Based on the proposed model, Kinetic Monte Carlo (KMC) simulations were performed. Obtained simulation results were compared with results of experiments on the growth of SiC on Si substrate with pre-deposited Ge impurity during carbon (C) deposition. They revealed a predictive behaviour of the developed model. The kinetic model takes into account deposition of C atoms on the substrate, formation of Si adatoms on the substrate (and therefore vacancies in substrate), diffusion of adatoms (Si, C, impurity) and SiC cluster nucleation. Two types of impurities interaction were studied: an attractive (growth of SiC clusters in a presence of surfactant) and repulsive (growth with antisurfactants, like Ge impurity during SiC/Si growth). A kinetic Monte Carlo (KMC) simulation code was developed to study the growth of Si clusters on Si with pre-deposited impurity within the proposed model. In the first step, simulations of SiC clusters nucleation without the pre-deposited impurity on Si(100) surface were performed and the clusters concentrations were obtained. Then the simulations of the SiC clusters' nucleation in

presence of pre-deposited impurities with different properties were carried out. In a subsequent step in the carried out simulations, attractive and repulsive impurities with different diffusivities on the Si surface were considered. It was found that the pre-deposition of both attractive and repulsive impurities leads to an increase in the SiC cluster concentration and decrease of their lateral sizes, as shown on Fig. 1. Attractive impurities act as additional nucleation centers, whereas repulsive impurities increase the adatom carbon concentration on the silicon surface. Furthermore, the SiC clusters concentration depends on the impurity diffusivity at the surface since impurities may aggregate and thereby reduce the number of the nucleation sites. The comparison of the simulation results with the predictions of the nucleation theory and experimental data were performed. The obtained results showed that pre-deposition of impurities on the Si substrate can significantly influence nucleation and growth of SiC clusters [4]. Thus, it is possible to control quality of the SiC/Si interface by implementing impurities.

M.N. Lubov1, J. Pezoldt2, Yu.V. Trushin1

Kinetic Monte Carlo simulation of impurity effects on SiC nucleation on Si

Fig. 1: SiC clusters on Si substrate (a) without predeposited impurity, (b) with predeposited impurity (black points)


Contact


98



99

Contact

1Universität zu Kiel2University of Luxembourg3Technische Universität Ilmenau

Jörg Kröger | +49 3677 69-3609 | joerg�kroeger@tu-ilmenau�de

[1] N. Néel, S. Schröder, N. Ruppelt, P. Ferriani, J. Kröger, R. Berndt, S. Heinze, Phys. Rev. Lett. 110, 037202 (2013).

[2] M. Endlich, A. Molina-Sánchez, L. Wirtz, J. Kröger, Phys. Rev. B 88, 205403 (2013).

Magnetoresistive effects at the ultimate size limit [1]: The tunneling anisotropic magnetoresistance (TAMR) of single Co atoms adsorbed on a double-layer Fe film on W(110) is observed by scanning tunneling spectroscopy. Without applying an external magnetic field, the TAMR is found by comparing spectra of atoms that are adsorbed on the domains and domain walls of the Fe film. The TAMR can be as large as 12% and repeatedly changes sign as a function of bias voltage. First-principles calculations show that the hybridization between Co d states of different orbital symmetries depends on the magnetization direction via spin-orbit coupling. This leads to an anisotropy of the density of states and thus induces a TAMR. Using the experimental approach of controllably forming single-atom contacts with the tip of a scanning tunneling microscope, it is possible to explore the TAMR at the atomic scale without external magnetic fields, which will allow future systematic studies for different atom types or atomic-scale structures, such as clusters or molecules. Financial support by the Deutsche Forschungsgemeinschaft through SFB 668 is acknowledged.

Kohn anomalies of graphene phonons [2]: Graphene on Ir(111) is archetypical in revealing subtle aspects of electron-phonon coupling and electron correlations in graphene. The weak graphene-metal interaction leaves its clear footprints in the phonon dispersion of graphene. The phonon disper-sion of graphene on Ir(111) has been determined by means of angle-resolved inelastic electron scattering using an Ibach spectrometer and density functional calculations. Kohn anomalies of the highest optical phonon branches are observed at the Γ and K point of the surface Brillouin zone. At K the Kohn anomaly is weaker than observed for pristine graphene and graphite. This observation is rationalized in terms of a decrease of the electron-phonon coupling due to screening of graphene electron correlations by the metal substrate. In addition and for the first time, the dispersion of all acoustic and optical phonon branches of graphene on Ir(111) is presented along high-symmetry directions of the surface Brillouin zone. Financial support by the Carl Zeiss Foundation is acknowledged.

R. Berndt1, M. Endlich3, P. Ferriani1, S. Heinze1, J. Kröger3,

Magnetoresistive effects at the ultimate size limit and Kohn anomalies of graphene phonons

A. Molina-Sánchez2, N. Néel3, N. Ruppelt1, S. Schröder1, L. Wirtz2

Fig. 2: STM images of graphene on Ir(111) (left) and dispersion of transverse optical graphene phonon around K (right)

Fig. 1: STM image of Co atoms on Fe-covered W(110) and sketch of adsorption geometry on magnetic domains

Funding: Deutsche Forschungsgemeinschaft through SFB 668,

Carl Zeiss Foundation

Fig. 2: Hot electron injecting kinetics from excited nano-Au to PZT

Fig. 1: Manipulations of surface plasmons in nano-Au/PZT hybrids for smart PEC applications


Contact


100





[1] M. Chitambar, Z. Wang, Y. Liu, A. Rockett, S. Maldonado, Journal of the American Chemical Society 134, 10670 (2012).

[2] D. Cao, Z. Wang, Nasori, L. Wen, Y. Mi, Y. Lei, Angewandte Chemie International Edition 126, 1 (2014).

[3] L. Wen, Y. Mi, C. Wang, Y. Fang, F. Grote, H. Zhao, M. Zhou, Y. Lei, Small 10, 3162 (2014).

[4] Z. Zhan, Y. Lei, ACS Nano 8, 3862 (2014).

[5] Y. Lei, W. Cai, G. Wilde, Progress in Materials Science 52, 465 (2007).

Although the Schottky barrier at contact of nano-metals and conventional semiconductors benefits the capture of hot charges, the transfer of the injected hot charges in the semiconductors is severely determined by the contacts of semiconductor/electrolyte, semiconductor /semiconductor and semiconductor/metals. These contacts are almost impossible to be changed if the semiconductor and the contacted material are fixed, limiting the choice of materials for conducting the injected hot charges efficiently [1]. For water splitting, a thin layer of TiO2 is usually deposited on nano-Au to collect the hot electrons. The intrinsic n type feature of the TiO2, however, forms a downwards band bending at TiO2/electrolyte that inhibits the injected hot electrons in the conduction band of TiO2 transferring to the electrolyte. Thus, Pt or cobalt based catalysts have to be adopted to adjust the band bending. Alternatively, ferroelectric materials possess a large, stable and manipulatable remnant polarization that produces a depolarization (internal) electric field extending over the whole film volume, enabling the relative devices of high efficiency in scavenging the excited charges. To be promising, the band bending at ferroelectric materials/electrolyte could be easily tuned by the poling pretreatments of the ferroelectric films, offering a smart system to harness hot charges maximally [2].Therefore, we employ a typical ferroelectric material, Pb(Zr,Ti)O3 (PZT), to capture the excited energy from

surface plasmons for photoelectrochemical (PEC) energy conversion. The nano-Au/PZT hybrids were fabricated on ITO by a standard ultra-thin alumina masks technique in combination of using physical vapor deposition and spin-coating techniques [3-5]. Interestingly, the photocurrent relevant to the stimulated surface plasmons cannot only be manipulated by placing the nano-Au arrays to varied positions in ITO/PZT, the orientations of the ferroelectric domains could also be utilized to switch the photocurrent signal. For ITO/PZT/nano-Au/PZT electrodes, the cathodic photocurrent is able to be tuned from 16.7 μA cm-2 to 2.4 µA cm-2, when the pre-poling bias on the ferroelectric films is switched from +10 V to -10 V, indicating a smart system to harvest the excited energy. In addition, transient absorption analysis reveals that the hot electrons generated through multi-photon absorption have a higher capability to overcome the Schottky barrier than the hot electrons rendered by surface plasmon decay. Accordingly, the height of the Schottky barrier at metals/semiconductors is not the only factor that determines the efficiency of hot electrons extraction from excited nano-metals. Thus, not only does this work offer a smart system to utilize the excited energy of surface plasmons for PEC energy conversion, it also provides insights on the hot electron injection kinetically.

Z. J. Wang, D. W. Cao, Y. Lei

Manipulations of surface plasmons in nano-Au/Pb(Zr,Ti)O3 for smart photoelectrochemical applications

Fig. 2: freestanding cantilever of Cr2AlC MAX phase

Fig. 1: doubly-clamped beams of Cr2AlC MAX phase

Fig. 3: Dependency of the Young’s modulus from the film thickness of AlN thin films



101

Contact

1 Group for Materials for Electrical Engieneering and Electronics2 Nanotechnology Group3 IMMS GmbH

Funding: Thuringian Minister of Education, Science and

Culture (TMBWK), (UseNEMS: B714-0965) and EFRE

Peter Schaaf | +49 03677 69-3611 | peter�schaaf@tu-ilmenau�de

[1] B. Hähnlein, et.al., “AlGaN based MEMS structures,” Phys. status solidi, vol. 11, no. 2, pp. 239–243, Feb. 2014.

[2] R� Grieseler et�al�, “Nanostructured plasma etched, magnetron sputtered nanolaminar Cr2AlC MAX phase thin films,”

Appl. Surf. Sci., vol. 292, pp. 997–1001, Feb. 2014.

[3] R. Grieseler et. al., “Residual stress measurements and mechanical properties of AlN thin films as ultra-sensitive

materials for nanoelectromechanical systems,” Philos. Mag., vol. 92, no. 25–27, pp. 3392–3401, Sep. 2012.

Commonly, the mechanical and stress properties of functional materials are determined using wafer bow methods or X-ray analyses. These methods accurately show the internal stress of the thin film, but they do not consider the behavior of MEMS and NEMS structures prepared from these thin films. Due to the etching processes, the state of internal stress may change and therefore must be investigated after the processing of the material. The project UseNEMS was focusing on the mechanical properties of AlN, GaN and AlGaN wide-bandgap semiconductors as well as nanolaminar materials and graphene. Wide-bandgap semiconductors, such as the mentioned group-III-nitrides, are prospective materials for ultrasensitive MEMS/NEMS devices. They exhibit a high ratio of Young’s modulus versus mass density, leading to a higher operation frequency for a given resonator size and geometry when compared to silicon [1]. Nanolaminar materials, in this case MAX Phases, on the other hand are characterized by their unique combination of materials properties. They combine high hardness and good chemical as well as thermal resistance, which are commonly ceramic properties, with metallic properties such as good electrical and thermal conductivity [2]. Due to its exceptional mechanical properties and even higher Young’s modulus to mass density ratio,

the investigation of freestanding graphene structures is important. In a first step, freestanding structures such as cantilevers and doubly-clamped beams were produced by plasma etching as shown in Figure 1 and 2. After that, the mechanical properties of these structures were investigated using a combination of vibrating excitation and Laser-Doppler vibrometry. The Eigenmodes of the vibrations led directly to the determination of the internal stress as well as the Young’s modulus of the freestanding structures. As a second approach for obtaining the mechanical properties of the beams, Raman spectroscopy was applied alongside and across of the beam. The results were compared to the mechanical properties of the initial thin film obtained by high resolution X-ray diffraction and FTIR ellipsometry [3]. In order to evaluate the results, a finite element simulation was applied, which included the etching processes as well as the vibrating properties of the beams. It could be shown that the Young’s modulus of the measured materials is strongly depending on the film thickness as shown in Figure 3. Furthermore, it could be shown that the literature values of the mechanical properties, which are mainly based on bulk material, are not always applicable for thin films, neither for MEMS nor for NEMS devices based on thin film technology.

R. Grieseler1, B. Hähnlein2, M. Stubenrauch2, K. Tonisch2,

J. Pezoldt2, S. Michael3, P. Schaaf1

Mechanical Properties of ultrasensitive Materials for MEMS and NEMS Devices – UseNEMS

Fig. 2: Young's modulus of 3C-SiC(111)Fig. 1: Residual strain in a 3C-SiC(111) beam


Contact


102

Funding: TMBWK contract B714-09065

1 Nanotechnology Group2 IMMS GmbH


[1] V. Cimalla, J. Pezoldt, O. Ambacher, J. Phys. D: Appl. Phys. 40, 6386 (2007)

[2] B. Hähnlein, M. Stubenrauch, S, Michael, J. Pezoldt, Mater. Sci. Forum 778-780, 444 (2014)

[3] J.-G. Guo and Y.-P. Zhao, Nanotechnology 18, 295701 (2007).

[4] R. Anzalone, G. D’Arrigo, M. Camarda, N. Piluso, A. Severino, F. La Via, Mater. Sci. Forum 711, 51 (2011)

Microelectromechnical systems (MEMS) cover a wide application range with varying designs from cantilevers/bridges to membranes. Due to its mechanical hardness, high electrical stability and chemical inertness SiC is a preferable material for these devices [1]. Unfortunately, the mechanical properties depend on the dimensions of the fabricated MEMS structures. Therefore, detailed knowledge of the thickness dependence of the materials used in the MEMS strucuture has to be accumulated to contribute to improved MEMS designs and reliable device operation. To gain the material propeties of 3C-SiC(111), a self consistent method using only a set of doubly clamped beams and cantilevers for the determination of the residual stress and the Young’s modulus of thin 3C-SiC(111) grown on Si(111) was developed. The developed method allows the determination of the stress and the mechanical properties in a wide range of residual stress. The experimental data were obtained measuring the length dependence of the resonance frequencies of cantilevers and doubly clamped beams. In general, bending of the cantilevers causes a decrease of the resonance frequency compared to cantilevers with negligible bending.

The analysis of the obtained data sets revealed a modified relationship between the bending of the cantilevers and the resonance frequency. The residual stress in the free standing structures was determined using the relation of the resonance frequency between beams and cantilevers depending only on the residual stress. The determined strain for a 50 nm thick beam as a function of the length is shown in Fig. 1 [2]. The obtained values exceed the strain caused by the thermal expansion mismatch between silicon carbide and silicon which indicates additional contributions from the defects in the 3C-SiC(111) layer. Fig. 2 [2] displays the dependence of the Young’s modulus versus 3C-Si(111) layer thickness. As it is evident, the Young’s modulus decreases with decreasing epitaxial layer thickness. The softening of the Young’s modulus is one of the possible behaviors’ for thin layers and might be due to tension or expansive relaxation in the near surface region of the micromechanical structures [3] or due to the high density of defects in the epitaxy [4]. It is worth mentioning that the obtained values for the 3C-SiC(111) exceed the values obtained for 3C.SiC(100) and 3C-SiC(110) which can be found in the literature.

B. Hähnlein1, M. Stubenrauch1, S. Michael2, J. Pezoldt1

Mechanical properties of thin 3C-SiC(111) films determined using MEMS structure

Fig. 2: a) combinatorial flow rate run, b) in situ UV-Vis and c) corresponding offline DCS spectra, d-f) SEM images of Ag prisms

Fig. 1: a) Au cubes, b) Au/Ag core shell NP, c) Au octahedron, d) Ag prisms, e) Au rods, f ) Au/Ag/Au core/double shell NPs



103

Contact

Group for Physical Chemistry / Microreaction Technology

Funding: DFG Kz�: KO 1403/22-1

Andrea Knauer | +49 3677 69-3643 | andrea�knauer@TU-Ilmenau�de

[1] A. Knauer, A. Thete, J. M. Köhler, et al., Chemical Engineering Journal, 166, 1164 (2011)

[2] A. Knauer, A. Csáki, J. M. Köhler, et al., Journal of Physical Chemistry C, 116, 9251 (2012)

[3] A. Knauer, J. M. Köhler, Chemie Ingenieur Technik, 85, 467 (2013)

[4] A. Knauer, A. Eisenhardt, S. Krischok, J. M. Köhler, Nanoscale, 6, 5230 (2014)

[5] A. Knauer, J. M. Köhler, Nanotechnology Reviews, 3, 5 (2014)

The application of the micro flow-through technique leads to a significant improvement of yield and homogeneity in case of rapidly proceeding nanoparticle syntheses and allows the generation of different types of high quality noble metal nanoparticles [1,2]. In Figure 1, a short overview consisting of SEM and TEM images of different types of plasmonic noble metal nanoparticles that have been obtained during the investigations of the authors is shown. Recently, it could be demonstrated that the droplet based synthesis method can easily be used for a tuning of the in-plane dipole plasmon mode of triangular silver nanoprisms, resulting in resonance shifts between the visible and the near infrared region [2,3]. Furthermore, the application of this technique was reported for the nanometer precise deposition of a silver shell around gold core nanoparticles [4].The utilized microreaction system comprises PC-controlled syringe pumps (Cetoni, nemesis system, Germany), a set of injectors for micro fluid segment generation, flow-through photometric sensors, and a fiber-based micro flow-through spectrophotometry for optical in situ analyses. A fast segment internal mixing was ensured in all synthesis experiments. The effective segment internal mixing conditions are the basis

for a focused nanoparticle nucleation, a rapid smoothing of concentration gradients, and thus, more homogeneous product particles. As an example thereof, the half width of the particle size distribution of 7.5 nm (conventionally stirred process) could be reduced in the synthesis of spherical Ag crystallization seed particles down to 2.3 nm (droplet based method) with a simultaneous reduction of the average particle diameter from 4.2 to 3.8 nm [2].A screening method was developed, which is based on an automated combinatorial variation of the reactant flow rates and thus reactant concentrations (Fig. 2a) [3,4,5]. With increasing edge length, the spectral position of the main dipole plasmon mode was red shifted from 550 to 900 nm (Fig. 2 b). As shown in Figure 2 c and d - f, the adjustment of the edge lengths of the triangular silver nanoprisms succeeded in fine gradations. DCS analyses confirmed narrow particle size distributions and SEM imaging a high yield of the desired shape. Furthermore, the synthesis of single-crystalline gold nanocubes, with adjustable edge lengths in a range between 55 and 80 nm, succeeded under application of a segment-based micro flow-through process.

A. Knauer, J. M. Köhler

Micro Flow-Through Synthesis of Plasmonic Noble Metal Nanoparticles in Micro Fluid Segment Sequences

Fig. 2: Two foils with half channels stacked face to face

Fig. 1: (A) structure of PDMS-Stamp (B) thermoformed PC foil

Fig. 3: Endothelial cells inside sinusoid channels

Fig. 4: Hepatocytes on the outer side of the sinusoid


Contact


104

Funding: 03WKCB01O; FKZ B714 09 064, 03Z1M511


Justyna Borowiec | +49 3677 69-1965 | [email protected]

[1] Sung J.H., Shuler M.L. Ann Biomed Eng. 40, 1289-300 (2012).

[2] McCuskey R.S., Liver 20, 3-7 (2000).

[3] Fernekorn, U., et al., Eng. in Life Sciences 11 ,133–139 (2011).

[4] Hampl J., Borowiec J., Häfner S. "3D-structured and surface modificated polymer scaffolds for complex cell assembly",

7th Workshop of Chemical and Biological Micro Laboratory Technology, February 25th – 27th, Elgersburg, 2014.

IntroductionIn vitro development of functional tissue plays a crucial role in a medical diagnostics and drug delivery. To better mimic the in vivo tissue environment, permeable 3-dimensional (3D) structures with heterogenous cell type and native tissue morphology are desirable. A number of attempts to construct such structures have been made, but the development of easy and highly reproducible methods still remains a challenge [1].Within the liver, the minimal functional element is the liver lobe containing liver sinusoids which were abstracted as a hexagonal arrangement of the channels. These channels are mainly revetted with endothelial cells intended to form the blood capillaries. Outside these capillaries hepatocytes are located. For normal liver function and hepatocyte survival, those hepatic sinusoids lined by liver sinusoid endothelial cells are essential [2].Methods and ResultsTo mimic basic liver organization we designed a mirrored structure of a porous polymer membrane which contains half channels filled with endothelial cells on one side and hepatocytes on the other side. When stacking these structures face to face an abstracted "vascularized" slice of a liver sinusoid is achievable. Figures 1 and 2 describe the schematic construction.To form sinusoid half channels on the polymer material we used microthermoforming process [3]. Additionaly,

to spatially control cellular micro-organization, local modification of the surface of polymer foils during and after the microthermoforming process was applied. To modify polymer surface during microthermoforming we used elastomeric polydimethylsiloxane (PDMS) stamps developed with standard microstructuring technologies. Stamps with lobule-mimetic structures were covered with appropriate macromolecules and used to transfer these molecules onto a selected area of polymer surface during the microthermoforming process. In this case the silicone tools acted as a combined micro patterning and thermoforming tool. We called this process 3D microcontact printing (3D μCP). Using this process various biomolecules suitable for the applied cell type can be coated on the surface of different thermoplastic polymers like polycarbonate (PC) or polylactid acide (PLA).Figure 3 shows endothelial cells growing into sinusoid structures of PLA porous foils coated with collagen during thermoforming. Selective cell adhesion onto modified regions and good cell vitality can be seen. In the next step exterior of the polymer substrate was completely covered with collagen and subsequently with hepatocytes. Figure 4 shows homogeneous adhesion of hepatocytes on the outer side of the sinusoid structures. Of particular interest is the merging of two mirrored structures coated with cells, as well as testing this system in the fluidic environment.

J. Borowiec, J. Hampl, U. Fernekorn, K. Friedel, M. Klett,

A. Schober

Micropatterned polymer scaffolds for guiding 3-dimensional cultivation of liver cells



105

Contact

1 Group for Materials for Electrical Engineering and

Electronics2 Electrochemistry and Electroplating Group

Funding: „Nanobatt“ (TNA VII-1/2012)


[1] M. Armand and T. M. Tarason, "Building better batteries", Nature 451, 652 (2008).

[2] R. A. Huggins, "Lithium alloy negative electrodes", J. Power Sources 81-82, 13 (1999).

[3] S. Ivanov, et al., J. Appl. Electrochem. 44, 159-168 (2014).

[4] S. Ivanov, et al., Electrochim. Acta. 104, 228 (2013).

[5] Y. Yan, et al., J. Mater. Chem. A, 1, 14507-14513 (2013).

The development of high performance electrode materials for Li ion battery is of great importance for electronic devices and renewable energy storage [1]. Si is considered as to be a promising anode material due to its high specific capacity and low discharge potential. However, the significant volume expansion of Si results in mechanical instability of the electrode and loss of capacity during cycling, which strongly hinders its practical application [2]. But the nanostructured Si (for example, nanowires or nanoparticles with diameter of less than 100 nm) enable the facile relaxation of the strain built up by lithiation and can avoid fracture, shows cyclic stability with high capacity. Figure 1 shows the mesoporous Si and mesoporous Si nanopillars which can be applied as promising anode [3].Titanium dioxide (TiO2) is also considered as one of the

promising anode materials for its nontoxicity, low cost, and excellent capacity retention. Moreover, it is safer due to the high operating voltage by which the formation of solid electrolyte interfaces (SEI) layers and electroplating of lithium can be avoided during cycling. However, the poor rate capability of TiO2 electrodes, caused by the low electrical conductivity and lithium diffusion coefficient, has strongly hindered so far its practical application so far. Herein TiO2 nanotubes [4] and hydrogenated black TiO2 nanoparticles [5] are used as anodes for Li ion batteries, and the rate performance is clearly improved, as shown in Figure 2.

Y. Yan1, C. Vlaic2, S. Ivanov2, D. Wang1, A. Bund2, P.

Schaaf1

Nanomaterials applied as electrodes for improved Li-ion batteries

Fig. 2: TiO2 nanotubes and hydrogenated black TiO2 nanoparticles as anodes and their electrochemical performance

Fig. 1: SEM images of mesoporous Si and mesoporous Si nanopillars as promising anodes for Li ion batteries

Fig. 1: Fast-field cycling relaxometer by Stelar s.r.l. Fig. 2: Frequency-dependent NMR relaxation times for bovine articular cartilage

0.01 0.1 1 10

0.1

ν (MHz)

T 1 (s)

untreated cartilage trypsinated cartilage collagenased cartilage


Contact


106

Funding: Carl-Zeiss-Stiftung


Siegfried Stapf | +49 3677 69-3671 | siegfried�stapf@tu-ilmenau�de

[1] E.Rössler, C.Mattea, A.Mollova, S.Stapf, JMR 213,112 (2011).

[2] E�Rössler, C�Mattea, S�Stapf, MRM, DOI: 10�1002/mrm�25292�

Based on the fundamental understanding of model polymer dynamics and structure that has been of continuing interest to the group for many years, cartilage, a biologically relevant tissue, has been investigated recently.Mammal articular cartilage has a layered structure and is composed of two main constitutes, namely collagen and proteoglycans, with water as an interstitial fluid. Osteoarthritis, a degenerative cartilage disease, affects an increasing amount of people. Therefore, there is ongoing research in this field especially using high-field MRI. However, fewer investigations have been done using low-field NMR methods.Applying our single-sided scanner to the tissue, we could take advantage of the improved contrast mechanisms at low fields. In this way, we have been able to characterize the depth-dependent structure by the use of different contrast parameters, like relaxation times and diffusion coefficients. Furthermore, due to the application of suitable contrast agents such as Gd-DTPA, we could quantify the proteoglycane and water concentration in

E. Rößler, C. Mattea

NMR investigations of enzymatically degraded bovine articular cartilage at low magnetic fields

our native tissue samples [1]. Degradation is simulated in our experiments by enzyme-controlled depletion of collagen and GAGs.A second low-field technique, which changes the static magnetic field in a defined low-field NMR range, is able to provide information on proton dynamics. Therefore, we investigated our samples using a Fast-Field Cycling Relaxometer (see figure 1) as well. Thereby, it was possible to gain information of different relaxation mechanisms inside our investigated specimens. As illustrated in figure 2, a remarkable property for biology samples could be seen, the so called Quadrupolar dips (Qdips). These are areas of enhanced relaxation, due to amino groups which provide an additional relaxation channel for protons. We investigated these Qdips in native and enzyme treated cartilage as well as isolated collagen and GAGs. Hereby, we underlined the dominating dependence of the Qdips on water concentration in the tissue [2].The discussed research activities are orientated towards low field modalities, which can be helpful in the early-stage diagnosis of cartilage degradation.



107

Contact

1 Micro- and nanoelectronic Systems Group2 University of Bayreuth, Germany3 Oxford Instruments, Great Britain

Funding: FP7/2007-2013, GA 318804 (SNM)

Ivo W� Rangelow | +49 3677-69-3718 | ivo�rangelow@tu-ilmenau�de

[1] Kaestner, M., Rangelow, I.W., et. al., Proc. SPIE – Int. Soc. Opt. Eng. 9049, 90490C (2014).

[2] Neuber, C., Kaestner, M., Krivoshapkina, Y., Budden, M., Rangelow, I.W, et.al, Proc. SPIE – Int. Soc. Opt. Eng. 9049,

90491V (2014).

[3] Kaestner, M., Hofer, M., and Rangelow, I. W., J. Micro/Nanolith. MEMS MOEMS 12(3), 031111 (2013).

[4] Kaestner, M., and Rangelow, I.W., Microelectron. Eng. 97, 96 -99 (2012).

To meet the growing demand for miniaturization, novel and sophisticated nanolithography methods and associated technologies such as resist technology are required. In general, the patterning resolution is determined by confinement of the lithographic reaction and from the size of the resist material itself. To extend nanolithography methods towards single nanometer regime, the understanding of the patterning effects as well as the pattern transfer capabilities of the resist at single digit nanoscale are essential. In conventional lithography methods the resist is exposed by high energy irradiation in order to produce secondary electrons, which in turn trigger chemical reactions in the resist forming the final pattern. In comparison, in electric field current-controlled scanning probe lithography (EF-CC-SPL) [1-4], low energy primary electrons are directly absorbed by the resist starting chemical changes for formation of a nanopattern. Irradiation energy and exposure dose can be controlled very well in EF-CC-SPL making the platform a good tool to explore lithographic performance of diverse resist systems shown in [1-2]. Herein, the SPL platform was operated in field emission regime, and the lithographic

perfomance was evaluated on very thin resist films (5-50 nm).For single nanometer manufacturing (SNM) an "all-dry" solvent free process flow was developed (Fig.1) including (a) high quality thin resist film (5-50 nm resist thickness) preparation by physical vapor deposition (PVD), b) ultra-high resolution positive-tone, development-less patterning of the resist by EF-CC-SPL, and (c) pattern transfer by plasma etching process. Thus, the targeted resist materials requires sufficient chemical and thermal stability for PVD, acceptable sensitivity and high resolution patterning capability in EF-CC-SPL, as well as sufficient etch resistance in plasma etching (Fig. 2).In summary, novel molecular glass resist materials are promising candidates therefor allowing PVD preparation, direct patterning by SPL as well as an improved etch selectivity compared to polymeric resists [2]. Because of the non-chemically amplified resist nature and the absence of corresponding material diffusion, the novel SPL resists have the potential to increase the patterning resolution capabilities at simultaneous reduction of the edge roughness (LER).

Y. Krivopshapkina1, M. Budden1, M. Kästner1, C. Neuber2,

H.-W. Schmidt2, M. Cooke3, I.W. Rangelow1

Novel Resist Materials for Electric Field Current-Controlled Scanning Probe Lithography

Fig. 2: Pattern transfer of EF-CC-SPL written corner features using HBr plasma etching process with an amplification of four [2]

Fig. 1: Schematic summary of the "all-dry" process flow for SNM with a) PVD of resist, b) EF-CC-SPL and c) plasma etching [2]

Fig. 2: Photocurrent density at 1.0 V vs. Ag/AgClFig. 1: SEM image of (a) colloidal crystal template and (b) inverse opals


Contact


108




[1] Z. B. Zhan, Y. Lei, ACS Nano 8, 3862 (2014)

[2] S. K. Yang, Y. Lei, Nanoscale 3, 2768 (2011)

[3] Y. Lei, S. K. Yang, M. H. Wu, G. Wilde, Chem. Soc. Rev. 40 (3), 1247 (2011)

[4] S. K. Yang, W. P. Cai, L. C. Kong, Y. Lei Adv. Funct. Mater. 20 (15), 2527 (2010)

[5] M. Zhou, J. Bao, Y. Xu, J. J. Zhang, M. L. Guan, C. L. Wang, L. Y. Wen, Y. Lei, Y. Xie ACS Nano, 8 (7), 7088 (2014)

M. Zhou, Y. Xu, C. L. Wang, L. Y. Wen, Y. Lei

Drawing inspiration from nature, photoelectrochemical (PEC) water splitting has been demonstrated as a feasible and cost-effective realization of an artificial analogy to photosynthesis. Aiming at solar harvesting and storage, semiconductor photoelectrodes hold great promise to be an attractive alternative to the naturally occurring photosystems.[1] Among all the widely investigated photocatalysts, monoclinic scheelite BiVO4 is a novel and promising candidate after striking a balance among various intrinsic features due to its suitable bandgap, proper band location, great stability and environment-friendliness. Despite these attractive characteristics, BiVO4 still suffers from several challenging technical points for large-scale implementations. The primary one is a relatively low mobility of photo-generated charges, which would naturally hinder the separation of electron-hole pairs and consume some solar conversion efficiency. Even from the viewpoint of a perfect bulk single-crystalline BiVO4, both calculated and experimental results indicate that alleviating charge migration problems, including surface charge transfer and bulk charge transport, shows a significant scope for improving the performances of PEC water splitting. In general, charge migration is strongly affected by the crystal structural features and the morphology of a photoelectrode. So as to meet the challenge, first, we can regulate the composition by doping to increase the

electronic conductivity intrinsically. Second, nanofabrication offers an opportunity for morphology innovation. A three-dimensional (3D) ordered macro-mesoporous architecture (a kind of inverse opals) can serve as an efficient candidate to improve charge migration. [2-4]Inspired by this concept, we realize the incorporating of additional mesoscale pores into periodic macroporous Mo:BiVO4 host scaffold.(see Fig. 1) [5] Superior photocurrent densities are achieved within expectation. (see Fig. 2) [5] This enhancement originates primarily from effective charge migration according to the analysis of PEC performance and electrochemical impedance spectroscopy. 3D ordered macro-mesoporous architecture possesses a more compact space occupation of materials through a larger interstitial space, which minimize the inner resistance of charge transport and the contact resistance at the electrode/electrolyte and electrode/current collector junction. The efficiency in elimination of produced O2 is also increased. Then the approach of precursor infiltration facilities the composition regulation, so we can further substitute for V5+ as Mo6+ to further optimize the charge migration of BiVO4. All the results highlight the synergistic effect of composition regulation and morphology innovation. This approach is helpful for creating more purpose-designed photoelectrodes with highly efficient performance.

Photoelectrodes Based Upon Mo:BiVO4 Inverse Opals for Photoelectrochemical Water Splitting


Fig. 2: Calculated angle-resolved reflectivity spectrum: a plasmonic mode is coupled to two excitonic modes; from Ref. [1]

Fig. 1: CHPI on silver: CHPI grows as 2-dimensional semiconductor sheets; the SPP can couple to far-field light via the exciton



109

Contact

Group for Theoretical Physics I

• J.J. Baumberg's group at Cavendish Lab, Cambridge, UK

• G.V. Prakas, Indian Inst. Technology, Dehli, India Funding: DFG via SPP 1391

David Leipold | +49 3677 69-3644 | david�leipold@tu-ilmenau�de

[1] W. Niu, L. Ibbotson, D. Leipold, E. Runge, G.V. Prakash, J.J. Baumberg, (submitted to Physical Review B)

[2] P� Vasa, R� Pomraenke, G� Cirmi, E� De Re, W� Wang, S� Schwieger, D� Leipold, E� Runge, G� Cerullo, C� Lienau, ACS Nano 4,

7559 (2010)

In view of their potentially extremely high operating speed, all-optical logic devices are often argued to bring the next break through in computing. Signal propagation in such devices will most likely be implemented via Surface Plasmon Polaritons (SPPs), i.e., optical excitations that travel along and are tightly confined to metal-dielectric interfaces. They are particularly useful because they allow for the subwavelength control of light in nanostructured integrated devices. In addition, SPPs create extremely high field strengths in spatial regions smaller than the diffraction limit which allows for strong nonlinear light matter interaction. These nonlinear processes will allow for basic logic-building blocks such as switches and transistors. Strong coherent coupling of SPP and exciton lead to the formation of novel collective modes called plexcitons or excimons [1,2]. They can be visualized as “undamped SPP”.In this work, we investigate a novel material class – hybrid organic-anorganic semiconductors – (here CHPI, a lead-iodate-based perovskite) as the optically active material and its interaction with SPPs on a silver grating (see Fig.1). CHPI-based devices can be operated at room temperature and are long-term stable, in contrast to the many material systems in which strong plexitons were observed earlier. Furthermore, CHPI is a promising material for photovoltaic applications.

The coherent coupling of the silver SPP and exciton manifests itself as avoided crossing in the SPP band structure of the angle-resolved reflectivity map (Fig. 2). This spectrum was calculated by solving the full vectorial Maxwell equations with an anisotropic material model by means of a finite-element method. The spectrum reproduces important aspects of angle-resolved reflectivity spectra measured in the Baumberg group (not shown, cf. Ref. [1]). In particular, strongly bound image biexcitons formed by the plexiton and its image "in" the metal with about 100 meV binding energy were observed and confirmed theoretically.By externally pumping the active material, the optical properties of a plexitonic device can be reversibly changed on an ultrafast timescale by saturation of the exciton and stimulated emission. In a similar setup with a j-aggregated dye, switching the reflectivity off and on on a time-scale of 1ps corresponding to an operating frequency of 1 THz has already been realized in experiments [2]! In future work, we shall reproduce such ultrafast operation at room temperature. This has the potential to be a major stepping stone on the way to commercial all-optical computing with high integration density and extraordinary processing speed.

D. Leipold, E. Runge

Plexcitons and Image-Biexcitons in Metal-Perovskite Nanostructures

1 Group of Materials for Electrical Engineering and Electronics2 Center of Micro- and Nanotechnologies Funding: "MAXCoat" DFG Scha 632/10

Peter Schaaf |+49 3677 69-3611 | peter�schaaf@tu-ilmenau�de

[1] M� Hopfeld et� al, “Thin Film Synthesis of Ti3SiC2 by Rapid Thermal Processing of Magnetron-Sputtered Ti-C-Si Multilayer

Systems,” Adv. Eng. Mater., vol. 15, no. 4, pp. 269–275, Apr. 2013.

[2] R� Grieseler et� al, “Formation of Ti2AlN nanolaminate films by multilayer-deposition and subsequent rapid thermal

annealing,” Mater. Lett., vol. 82, pp. 74–77, Sep. 2012.

[3] M. Hopfeld, et. al, “Tribological behavior of selected Mn+1AXn phase thin films on silicon substrates”, Surf. Coatings

Technol�, Aug� 2014

IntroductionMn+1AXn (MAX) phase materials combine a unique combination of material properties. Due to their nanolaminar structure, they show high hardness values as well as good chemical and thermal stability, which are typical ceramic properties. Additionally, MAX phases exhibit a good electrical and thermal conductivity, which are typically metallic properties.Thin film preparationDuring this research project, a unique method of producing MAX phase thin films was developed, based on the deposition of multilayer systems consisting of elemental single layers by pulsed laser deposition and subsequent rapid thermal annealing. This method was transferred to the magnetron sputtering method and reveals high quality MAX phase thin films [1], [2]. High resolution transmission electron microscopy (HRTEM) micrographs as well as X-Ray diffraction pattern could confirm the formation of MAX phases. Figure 1 shows a HRTEM micrograph of a Ti3SiC2 MAX phase as well as the unit cell of this phase. Tribological characterizationBesides the electrical conductivity of these thin films, one focus of investigation was set to the tribological properties [3]. Therefore, three different MAX phase thin films were

produced on silicon and steel (1.4401) substrates: Ti3SiC2, Ti2AlN and Cr2AlC. As counter material, a steel ball (1.3505, bearing steel) was used. The setup of the tribological investigation is shown in Figure 2. A reciprocating module was used to investigate the friction and wear behavior of the MAX phase on a total distance of 1 m. Tribological analyses have shown, in general, lower friction coefficients and lower wear rates of the material systems compared to the pure substrates. As MAX phases have a good electrical conductivity, further analysis of the tribological behavior applying electrical loads were additionally performed. Field of application of MAX thin filmsTo evaluate the usability of MAX phases in MEMS or NEMS structures, micro-scale cantilevers and doubly-clamped beams of Cr2AlC were produced by plasma etching. An array of doubly-clamped beams with different length is shown in Figure 3. The vibrational behavior was investigated using electrostatic excitation and a Laser-Doppler vibrometer. Applying these methods the Young’s modulus of the thin films could be determined. Using indentation hardness measurement, the values of the Young’s modulus was determined. In both cases, it was determined to be approximately 180 GPa for the 500 nm thin film.

M. Hopfeld1, R. Grieseler1, A. Vogel1, Th. Kups1,

H. Romanus2, P. Schaaf1

Preparation and application of nanolaminar Mn+1AXn

phase thin films – MAX-Coat

Fig. 3: Plasma etched doubly-clamped beam of the MAX phase thin film

Fig. 2: Setup of the reciprocating ball-on-disc device

Fig. 1: (a) HRTEM image of Ti3SiC2. (b) iFFT image showing the typical zig-zag structure of Ti3SiC2, (c) theoretical structure Ti3SiC2


Contact


110

Fig. 2: Result of the EDX line scan along the cross-section of LTCCFig. 1: Cross-section of the bonded area of LTCC



111

Contact

1 Group for Materials for Electronical Engineering and

Electronics2 Electronics Technology Group

Rolf Grieseler | +49 03677 69-3435 | rolf�grieseler@tu-ilmenau�de

[1] R. Grieseler et. al, “Diffusion in thin bilayer films during rapid thermal annealing,” Phys. status solidi, Aug. 2014.

[2] R. Grieseler et. al. “Bonding of low temperature co-fired ceramics to copper and to ceramic blocks by reactive aluminum/

nickel multilayers,” Phys. status solidi, vol. 209, no. 3, pp. 512–518, Mar. 2012.

[3] T� Welker et� al� “Bonding of ceramics using reactive NanoFoil®,” in 2012 4th Electronic System-Integration Technology

Conference

Reactive multilayer systems are formed of alternating metal thin films in the range of 10 to 25 nm. During the formation of intermetallic phases, a negative formation enthalpy is necessary to observe a self-propagating high-temperature synthesis. A schematics of the reaction is shown in Figure 1. Due to the exothermal reaction of the two metals, a temperature increase of the system can be generated up to 1500°C. The most common metal combination exhibiting this exothermal reaction is the Al-Ni system. There are different possibilities of influencing the reaction. Typically the reaction velocity as well as the reaction temperature strongly depends on the single layer thickness as well as the total thickness of the system. Another possibility is the application of other material systems. In this work, besides the Al-Ni system, three other systems were investigated: Al-Ti, Ti-Si, and Al-Cu. The three systems are very different in the thermal and chemical properties and; therefore, the reaction generating the heat is different. One of the influencing properties is the diffusion of these materials. It could be shown, that the literature values of the diffusion constants as well as the activation energy for the diffusion is not applicable for these films. Therefore, determining the correct diffusion properties is necessary [1]. Afterwards, the velocity of reaction front as

well as the maximum temperature was determined. It could be shown, that the Al-Cu system exhibited the slowest reaction front velocity and also the lowest heat of reaction, whereas the Ti-Si system reached the highest heat of reaction and the fastest velocity of the reaction front. For the application in the packaging of integrated circuits, in a first step the Al-Ni system was applied in the first step [2], [3]. The commercially available Nanofoils® where used and compared to the performance of direct sputtered Al-Ni multilayer films. As an example system, two low temperature co-fired ceramics (LTCC, Du Pont 951) with a brazable silver paste on top were bonded using the two possibilities. In Figure 1 a micrograph of the bonded system is shown. In order to investigate the material composition after the reaction of the multilayer system, an energy dispersive X-ray analysis was applied as shown in Figure 2. Tensile testing demonstrated the quality of the bond. Whereas the commercially available Nanofoil® led to a high tensile strength and therefore a good bond, the direct sputtered multilayers exhibited a low tensile strength. Thus, an optimization considering the possibility of choosing other material systems as well as tuning the multilayer systems according to the used solder materials as well as devices and materials that should be bonded is still necessary.

R. Grieseler1, T. Welker2, Th. Kups1, J. Müller2, P. Schaaf1

Reactive multilayer systems and their application in the packaging of integrated circuits

Funding: TMBWK contract B714-09065

1 Nanotechnology Group2 Group of Materials for Electrical Engineering and

Electronics

Bernd Hähnlein | +49 3677 69-1875 | [email protected]

[1] B. Hähnlein, P. Schaaf, and J. Pezoldt, Size effect of Youngs modulus in AlN thin layers, J. Appl. Phys. 116, 124306 (2014)

The ongoing miniaturization of microelectromechanical systems (MEMS) to nanoelectro-mechanical systems (NEMS) has routed to the fabrication of ultrasensitive sensors. This requires knowledge of the dimension dependent mechanical properties of the individual material systems and their predictive simulation. Device design, especially in the nano range, requires knowledge of the mechanical properties of the used materials. They are determined by different experimental methods or by theoretical investigations. Using the length dependence of resonance frequencies of MEMS structures, it could be demonstrated that the Young’s modulus of AlN decreases if the thickness of the AlN layer decreases below 300 nm. The different AlN layers were grown directly on n-Si(111) by MOCVD. Standard photolithography processes were used for structuring the samples. With chlorine and fluorine plasma etching processes, the structures were suspended. The resulting cantilevers and beams (Fig. 1), and their frequency properties, were measured with a Laser Doppler vibrometer. The geometric dimensions were determined via scanning electron microscopy. A slightly modified Euler-Bernoulli-theory (EBT) in terms of curvature and strain was used to determine the elastic properties of thin AlN layers. Because

of faulty literature derivation, a curvature bending theory for stressed cantilevers had to be developed. This method allowed the investigation of the strain gradients within the AlN layer. It could be shown that the modified EBT is able to describe the eigenfrequency behavior of the structures with very high accuracy. From this theory the Young's moduli could be extracted which exhibited thin film flattening (Fig 2). In comparison to recent surface relaxation and surface elasticity models, it could be demonstrated that the ultra thin film flattening of the Young’s modulus for heterogeneous grown materials is not covered by these theories. Further investigations showed that the polycrystallinity of the AlN, especially grain size and grain growth, causes this behavior. A theoretical model was found describing its influence. Unfortunately, it was not able to describe the thickness dependency of the elastic modulus. Hence, an approach for modification was made considering the increasing grain size with increasing layer thickness allowing a qualitative description of the Young's modulus in the thin film limit. With this underlying theory it could be shown that grain size and grain growth show significant influence on the mechanical parameters for thin films with a thickness below 100 nm.

Bernd Hähnlein1, Peter Schaaf2, Jörg Pezoldt1

Size dependency of Youngs modulus in thin AlN layers

Fig. 2: Dependency of the Young's modulus as a function of layer thickness

Fig. 1: SEM picture of 100nm thin beams and 120nm thin cantilevers


Contact


112



113

Contact

Group of Materials for Electrical Engineering and

Electronics

Funding: „FunPartY“ (DFG Scha632/20-1)


[1] A. Herz, D. Wang, Th. Kups, P. Schaaf, Journal of Applied Physics 116, 044307 (2014).

[2] D. Wang, P. Schaaf, Materials Letters 70, 30-33 (2012).

[3] A. Herz, D. Wang, R. Müller, P. Schaaf, Materials Letters 102-103, 22-25 (2013).

[4] A. Herz, D. Wang, P. Schaaf, Journal of Vacuum Science and Technology B 32, 021802 (2014).

[5] D. Wang, R. Ji, A. Albrecht, P. Schaaf, Beilstein Journal of Nanotechnology 3, 651-657 (2012).

Thin films are metastable due to their enhanced surface-to-volume ratio, resulting in thermally induced film agglomeration even in solid state. The driving force for the so-called dewetting is the minimization of surface and interfacial energies of the film-substrate system. Therefore, dewetting of thin films has gained much attention due to its importance in the field of microelectronics.Thin metal films are of current focus in the dewetting research community. A comprehensive understanding of the mechanisms behind thin film agglomeration (i.e., in the context of kinetics and thermodynamics) is necessary to potentially overcome this phenomenon, which is one aspect of this project.On the other hand, self-assembly of thin films can also be beneficial as a useful side effect of the dewetting of thin solid films is producing single-crystalline, nearly defect-free

faceted particles. Their average size can be controlled by the layer thickness - the thinner the film, the smaller the particles - and the type of the substrate (flat or patterned). Final shape of the particles is determined by the equilibrium crystal (or Wulff) shape. The composition can further be considered as another determining factor for synthesizing functional alloy micro- and nanoparticles. Thus, another aspect of this project is particle research for potential applications in ecology or information technology.The current model system Au-Ni, which shows partial miscibility at elevated temperatures, turns out to be convenient for investigating features in the course of bilayer dewetting and alloy particle formation. Recently, dewetting and subsequent dealloying was used to synthesize ordered arrays of nanoporous Au nanoparticles out of an Ag/Au bilayer thin film.

A. Herz, D.Wang, P. Schaaf

Solid-state dewetting of thin films and the formation of micro- and nanoparticles

Fig. 1: Sketch of research interests: an obvious issue is what happens in the case of bilayer or alloy thin films

Fig. 2: Cross sectional TEM image of a 3C-SiC post overgrown with a multi-quantum well

Fig. 1: Cross section TEM image of a 3C-SiC post overgrown with cubic GaN


Contact


114

1 Department of Physics, Universität Paderborn2 Nanotechnology Group


[1] E.A. Fitzgerald, G.P. Watson, R.E. Proano, D.G. Ast, J. Appl. Phys. 65, 2220 (1989)

[2] R.M.Kemper,T.Schupp, M.Häberlen, e.a., J. Appl. Phys. 110, 123512 (2011)

[3] R. Kemper, L. Hiller, T. Stauden, e.a., J. Cryst. Growth 378, 291 (2013)

[4] R�M� Kemper, C� Mietze, L� Hiller, e�a� Phys� Status Solidi C 11, 265

One of the key issues in group III-nitride growth is the improvement of the structural quality because defects like dislocations limit the device performance. Many of these defects are due to the lattice mismatch with the substrate. For c-GaN, 3C–SiC is the preferred substrate, as exhibited by a lattice misfit of 3.5%. This is meant to be the main reason for the present high dislocation density in c-GaN. One possibility of eliminating these misfit dislocations is the reduction of the growth area [1]. In recent work it was shown that another source of defects is the presence of two types of anti-phasedomains in the 3C–SiC/Si substrate sharing equal parts of the growth surface [2]. The use of dimensionally reduced 3C-SiC(100) with single domains allows for the reduction of the defect densities and the influence of the anti phasedomains on the grown cubic III-Nitride epitaxial layers and cubic GaN/AlN multi-quantum wells.Patterning of the 3C–SiC (001) surface is achieved by electron beam lithography and a subsequent reactive ion etching process. Arrays of 5x5 nanostructures are repeated several times on the substrate surface with etched downs paces in between. The posts have top edges with a length of about 500 nm, a height of about 700 nm and are aligned parallel

and perpendicular to the [110] direction of the substrate. Cubic GaN and the AlGaN multi-quantum wells were grown by plasma-assisted molecular beam epitaxy (MBE) on nanopatterned 3C–SiC/Si (001) surfaces. After growth, the c-GaN epilayer was characterized by electron backscatter diffraction (EBSD) and the selective-area-grown GaN was analyzed by cross-section transmission electron microscopy (TEM).On top of the nano-sized 3C–SiC posts, nearly defect-free phase-pure c-GaN with excellent structural properties was grown (Fig. 1) [3]. On the side walls of these posts, however, the GaN layer contains a high density of {111}planar defects. For c-GaN grown in the intermediate area between the 3C–SiC posts, the stacking fault density in adjoining anti-phase domains is markedly different, with the domain boundary clearly separating regions of low and high planar defect densities. In contrast, the grown cubic AlN/GaN MQWs on pre-patterned 3C-SiC substrates by means of MBE contain {111} stacking faults originating from the first layers grown on the 3C-SiC posts (Fig. 2) [4]. Therefore, improvements of the MQW morphology can be achieved only by eliminating the island growth of these initial layers.

R.M. Kemper1, L. Hiller2, J.K.N. Lindner1, J. Pezoldt2, D.J. As1

Structured 3C-SiC(100) substrates for cubic III-Nitride nanoheteroepitaxy



115

Contact

1 Biomechatronics Group2 Center of Micro- and Nanotechnologies3 iba Institut für Bioprozess- und Analysemesstechnik e.V.

Heilbad Heiligenstadt

Hartmut Witte | +49 3677 69-2456 | hartmut�witte@tu-ilmenau�de

[1] M. Schmidt et al., Proceedings 58th Ilmenau Scientific Colloquium, Ilmenau University of Technology (2014).

[2] S. Mende, Master Thesis, Ilmenau University of Technology (2014).

Many rodents such as rats are crepuscular or nocturnal and inhabit caves and subterrestrial tunnels. This aspect suggests that the visual sensory system does not play a key role in environmental orientation, but the sense of touch may function as major guidance ability. This tactile sense is achieved by sinus hairs also called vibrissae [1]. Carpal sinus hairs (located on the forelimb’s distal end) of mammals have not yet been investigated comprehensively. Therefore, carpal sinus hairs of Rattus norvegicus were examined with respect to the internal structure and present components as well as the chemical composition and its distribution on the surface.Visualisation of anatomical components was accomplished using light and electron microscopic techniques such as reflected-light and transmitted-light microscopy (both realised at the Technische Universität Ilmenau), scanning electron microscopy (SEM) and focused ion beam (FIB). SEM measurements were performed at the Institute for Bioprocessing and Analytic Measurement Techniques (IBA), Heilbad Heiligenstadt and FIB images were taken at the Center of Micro- and Nanotechnologies (ZMN), Ilmenau. Special microscopic methods were used to investigate the

phenomena of autofluorescence and birefringence of sinus hairs (both performed at the Technische Universität Ilmenau). With the aid of energy dispersive X-ray spectroscopy (EDS, done at IBA, Heilbad Heiligenstadt), vibrissal cross sections were analysed to determine the chemical composition and its distribution on the surface.Several results have shown the resemblance of sinus hairs to fur and human scalp hair regarding the anatomical structure and chemical composition. The evidence of three layers referred to as cuticle, cortex and medulla was adduced. Preliminary results of the chemical analysis realised by EDS measurements indicated an asymmetrical distribution of sulphur across the surface of cross sections of a carpal sinus hairs (see Fig. 1). It has been shown that the cuticle contains a higher sulphur content than cortex or medulla. This may act as an indicator for the presence of cystine, whose purpose is to provide stability, sturdiness and protection against physical, chemical and mechanical influences. The scanning electron microscopy of the focused ion beam milling provides an illustration of pores or enclosures in the cortex layer of a carpal sinus hair (see Fig. 2). [2]

T. Helbig1, S. Mende1, H. Romanus2, H. Rothe3, D. Voges1, H. Witte1

Studies on the Internal Structure of Carpal Sinus Hairs

Fig. 2: FIB image of the milled cortical area of a carpal sinus hair (2100 x)

Fig. 1: EDS map of a sliced carpal sinus hair (1100 x). Distribution of secondary electons (grey), carbon (turquoise) and sulphur (red)

Fig. 2: XPS spectra of the O1s core level state of the bath and air side of fresh and aged glass samples

Fig. 1: XPS overview scan of a glass sample's bath and air side. All expected elements are clearly visible


Contact


116

Funding: Freistaat Thüringen (Landesgraduiertenschule

"PhotoGrad")

1 Research Group Surface Physics of Functional

Nanostructures2 Group of Inorganic-Nonmetallic Materials

Stephanie Reiß | +49 3677 69-3406 | stephanie�reiss@tu-ilmenau�de

[1] A. Mekki, D. Holland, C.F. McConville, M. Salim, J. Non-Cryst. Solids 208, 267 (1996)

Glass is an important material with a wide application field. Most glasses undergo processes of coating, silvering or laminating to modify their characteristics and improve their durability. The success of these procedures depends on the alternating influence between manufacturing process and glass surface. One of the aims is to minimize the silicate network's dissolution, a glass destroying aging process limiting the lifespan of glass devices. X-ray Photoelectron Spectroscopy (XPS) is a powerful instrument to investigate surfaces and their interaction with the environment due to its high surface sensitivity. It gives an insight in surface composition and alterations. Therefore, we can study the degradation of glasses subject to its manufacturing process and other environmental parameters.The investigated glasses were manufactured in a float process. Here, the glass melt gets cooled on a liquid tin bath to produce a very flat surface without air inclusions. Hence, we have a surface side with tin enrichment (bath side) and one without (air side). To investigate the tin's effect on glass degradation, we compared fresh samples to aged ones. For aging, samples were stored in a climate chamber at a humidity of 85% and a temperature of 85°C for 7 days. The

bath and air sides were investigated and compared to each other. Charging effects during XPS measurements were compensated by an electron gun.The spectra shown in Fig. 1 reveal the expected chemical glass composition with additional tin peaks on the bath side. The analysis of the O1s core level spectra shows 2 components (see Fig. 2) fitted by a Gauss-Lorentzian function. The component at ~532eV is linked to bridging oxygen (BO) linking 2 silicons (Si-O-Si). The one at ~530.3eV is related to negatively charged non-bridging oxygen (NBO) where one silicon is substituted by a positive alkali ion [1]. Thus, changes in the ratio of these O1s components give insight in the progress of network dissolution. For the bath side the BO/NBO-ratio decreases from 10.8 to 2.2 after aging. While the fresh sample's air side clearly shows the BO and NBO component, only one can be seen after aging. Its FWHM is wider for each single component of the fresh sample, and its binding energy lies with 531.6eV in between them. This leads to the conclusion that this peak is a superposition of different components. The stronger degradation of the air side thus indicates an anticorrosive effect of tin.

S. Krischok1, E. Rädlein2, S. Reiß1, S. Urban2

Surface degradation of float glasses investigated by XPS



117

Contact




[1] Y. Lei, W. Cai, G. Wilde, Progress in Materatails Science 52, 465 (2007).

[2] D. Cao, C. Wang, F. Zheng, W. Dong, L. Fang, M. Shen, Nano Letters 12, 2803 (2012).

[3] M. Zhou, J. Bao, Y. Xu, J. Zhang, J. Xie, M. Guan, C. Wang, L. Wen, Y. Lei, Y. Xie, ACS Nano 8, 7088 (2014).

[4] D. Cao, Z. Wang, Nasori, L. Wen, Y. Mi, Y. Lei, Angewandte Chemie International Edition 126, 1 (2014).

As the only active materials in the photovoltaic and photoelectrochemical cells for solar energy conversion, conventional semiconductors have been studied thoroughly for the past several decades [1]. The progress of technologies in semiconductor device fabrications promotes the energy conversion efficiency close to the theoretical values based on the band gap analysis of the particular semiconductors. The current dogma for analyzing the energy conversion devices with traditional semiconductors, however, consists of two limits: (1) the photovoltage of the devices is limited by the band gap of the employed semiconductors; (2) the charge transfer direction is confined and fixed by the junctions of the semiconductor/semiconductor, semiconductor/metal or semiconductor/electrolyte. An alternative direction for overpassing the limits of the common semiconductors is to fabricate solar energy conversion devices with ferroelectric materials. Ferroelectric materials, typically BiFeO3 (BFO) and Pb(Zr,Ti)O3 , possess a large, stable and tunable remnant ferroelectric polarization which produces a depolarization (internal) electric field extending over the whole film volume, enabling the relative devices of high efficiency in separating photo−generated charges and switching charge transfer directions [2]. Accordingly, ferroelectric materials exhibit unique abnormal photovoltaic effects. By controlling the conductivity of the ferroelectric domain walls, the detected open circuit potential (Voc) of BFO has been achieved as

high as 50V, which is more than 50 folds larger than that from regular Si solar cells. This indicates that a huge Voc from ferroelectric materials is achievable even without considering the band gap limit.Herein, rather than conventional semiconductor photoelectrodes [3], we focus on BFO ferroelectric photoelectrodes to break the limits imposed by common semiconductors. Attributed to the prominent ferroelectric properties, the photoelectrodes possess an impressive capability in tuning the transfer of photo−excited charges generated either in BFO or the surface modifiers by manipulating the poling conditions of the ferroelectric domains. At 0 V vs. Ag/AgCl, the photocurrent could be switched from around 0 μA/cm2 to 10 μA/cm2 and the open circuit potential also exhibits a good tunability with the value change from 33 mV to 440 mV, when the poling bias of pretreatment is manipulated from −8 V to +8 V. Additionally, the pronounced photocurrent from charge injection of the excited surface modifiers could as well be quenched by switching the poling bias from +8 V to −8 V. Thus, this communication offers a feasible strategy for designing smart photoelectrochemical systems as to operate photoelectrochemical reactions, such as water spliting reduction reactions and oxidation reactions, on a single ferroelectric electrode freely [4].

D. W. Cao, Z. J. Wang, Y. Lei

Switchable charge transfer in the photoelectrochemical energy conversion of ferroelectric electrodes

Fig. 2: Switchability on charge transfer excited in surface modifiers

Fig. 1: Switchability on charge transfer excited in BFO


Fig. 2: Setup (right part): Customized HV vacuum chamber with imaging setup inside

Fig. 1: Setup (left part): Optics on the rail with camera for coarse alignment


Contact


118

1 Synchrotron SOLEIL, France2 Micro- and nanoelectronic Systems Group

Ivo W� Rangelow | +49 3677 69-3718 | ivo�rangelow@tu-ilmenau�de

[1] S. Kubsky, D. Olynick, P. Schuck, J. Meijer, I. W. Rangelow, US Patent Application Publication US2011/0055985 A1 (2011).

[2] I� W� Rangelow et al�, Surface and Interface Analysis, vol� 33, pp� 59-64, 2002�

[3] T� Ivanov et al�, Microelectronic Engineering, vol� 67-68, pp� 550-556, 2003�

[4] U. Wenzel, I.W. Rangelow, and S. Kubsky, submitted for publication.

IntroductionAt Synchrotron SOLEIL we have installed a novel AFM-spectroscopy system that works with synchrotron radiation. Such a combination enables simultaneous measurement of complementary sample properties at a nanometre scale. That is increasingly important as the region of interest is easily lost when instruments are changed. The SRAFM [1] is based on a self-actuating piezoresistive cantilever fabricated at the Technische Universität Ilmenau [2,3]. Therefore, the optical deflection detection inherent to the standard AFM may be omitted. The synchrotron radiation is transferred through a sub-wavelength hole in the metallized AFM tip to the sample surface. Since the AFM tip may be modified and functionalized, the SRAFM addresses a broad range of applications in research and industries.DesignThe imaging set-up is implemented into a customized high vacuum (HV) chamber in an unique vertical arrangement which allows for easier alignment with the synchrotron radiation. A mobile support carries the HV chamber, hence,

the SRAFM may be transported to different beamlines at the synchrotron. The imaging set-up consists of piezo-based linear actuators (SmarAct GmbH), one for the cantilever and one for the sample. The scanning process is run by the Nanonis controller (SPECS Surface Nano Analysis GmbH) . The optics for focusing the synchrotron radiation are aligned on a rail. For light collection, optics are installed at the backside of the sample. An optical fiber transmits the light signal to an avalanche diode from where the light signal is taken by a second Nanonis controller. Both controllers are synchronized. The sub-wavelength hole in the AFM tip is prepared through Focused Ion Beam (FIB) processing.OutlookThe SRAFM works at any pressure from ambient to vacuum as well as with gases. The scanning is done in non-contact mode with a resolution of 1 nm. Information on a larger scale is provided through field stitching [4]. Tests with laser radiation have been successfully carried out. Next, there will be the scanning of fluorescent standard samples before the SRAFM will be run with synchrotron radiation.

U. Wenzel1,2, S. Kubsky1, T. Ivanov2, M. Kästner2, M.

Hofer2, I. W. Rangelow2

The SRAFM (Synchrotron Radiation Atomic Force Microsope)

Fig. 2: Breaking edge of a barium ferrite thin film on an alumina substrate

Fig. 1: Segmented sputtering target made of barium ferrite



119

Contact

Funding: iKersatec, funded by the Federal Ministry of

Economic Affairs and Energy

1 Eletronics Technology Group2 Group for Inorganic-Nonmetallic Materials

Nam Gutzeit | +49 3677 69-3453 | nam�gutzeit@tu-ilmenau�de

[1] N. Gutzeit: "Herstellung von Ti4+-dotierten hexagonalen ferritischen Dünnschichten durch HF Co-Sputtern" Diplomarbeit,

TU Ilmenau, 2011

[2] P. Quiroz; B. Halbedel: Synthesis and characterization of Ti-doped barium hexaferrite powders by glass crystallization

technique. In: 54th International Scientific Colloquium Ilmenau, Verlag ISLE (2009), S. 3–10

Miniaturized ferrite components open up new ways for communication technologies with microwave devices. Within the project iKersatec new communication technologies in the Ka frequency band for the inter-satellite and the satellite-earth communication are investigated at the Electronics Technology Group. A promising opportunity to produce small microwave devices is the use of sputtered barium ferrite thin films. At the Centre of Micro- and Nanotechnologies, a sputtering process with in-house made ceramic sputtering targets was developed [1].To ensure a stable barium ferrite deposition, a single-phase sputtering target was made of barium ferrite nanopowder. This raw material was produced by glass crystallization techniques in cooperation with the Group for Inorganic-nonmetallic Materials within the Institute of Micro- and Nanotechnologies MacroNano®. The glass crystallization technique offers the opportunity to produce barium ferrite powders with particle sizes of around 50 nm and very low

contaminations [2]. For the use at the Ka frequency band, the resonance frequency of the barium ferrite can be decreased by the substitution of iron ions with titanium ions, which is done by the variation of the raw materials of the glass crystallization technique or a co sputtering process with different targets or target compositions (Figure 1).The sputtering of barium ferrite films with different chemical composition and different thicknesses on alumina substrates was shown at the Centre of Micro- and Nanotechnologies. Figure 2 shows the breaking edge of a barium ferrite thin film on alumina. The barium ferrite phase of the film was detected by GID XRD.The next steps for the production of miniaturized microwave devices are the structuring of these films and the deposition on LTCC substrates. LTCC substrates offer good integration capabilities and allow usage in harsh environments.

N. Gutzeit1, B. Halbedel2, J. Müller1

Thin film barium ferrite integration in LTCC for new communication technologies

Fig. 4: SEM micrograph of a thick film electrode

Fig. 3: 3D thick film electrodes on ceramic fingers

Fig. 2: 3D MEA chip for the use with the MEA2100-System

Fig. 1: Schematic view of the 3D MEA assembly

Contact


120

PROCESS TECHNOLOGY

1 Electronics Technology Group2 Nano-Biosystem Engineering Group

Heike Bartsch | +49 3677 69-3440 | [email protected]

[1] Williamson et al (2012) 3D capacitively coupled MEA on a 3D microstructure array with interface technology, 8th

International MEA Meeting, Reutlingen, Germany

[2] Heuschkel et al (2002) A three-dimensional multi-electrode array for multi-site stimulation and recording in acute brain

slices, Journal of Neuroscience Methods 114, 135-148

[3] 3D engineered neural networks coupled to Micro-Electrode Arrays: Development of an innovative in-vitro experimental

model for neurophysiological studies (2013) DOI: 10.1109/NER.2013.6696094

MotivationNeurobiological concepts based on state-of-the art technology have so far lacked the complexity of actual high-level neurobiological systems. Two key advances are needed to improve our understanding of such systems: in vitro 3D-neuronal cell cultures (including multiple types of neural cells), and 3D MEA systems for measuring such 3D-cultures. These requirements call for smart system concepts which are presented in [1]. Low temperature co-fired ceramics (LTCC) are chosen as material system for the MEA design because those ceramics enable complex multilayer assemblies and feature excellent temperature and solvent stability. RealizationThe material Green TapeTM from DuPont Nemours is chosen because its compatibility and those of available metallisation with cell cultures has already been proven. An LTCC multilayer board with gold electrodes is the base of the 3D MEA. Fig. 1 depicts a schematic cross section of the assembly. LTCC vias serve as electrodes in cell contact. They are interconnected via the buried wiring and a 90° solder contact with printed gold pads. The layout of these gold pads is designed to fit the MEA2100-System for in vitro recording from Multi Channel Systems and thereby enable comparable data processing to established 2D MEAs Slots. The realised 3D MEA is depicted in fig. 2. The 3D electrodes have a diameter of 85 µm and are arranged on ceramic fingers as shown in fig. 3. In addition

to the 3D electrodes on the fingers, each MEA is equipped with 3 x 10 2D electrodes, which are situated in the near vicinity of the bars at the bottom of the MEA. Additionally, one 2D counter electrode with a diameter of 2 mm is situated at the MEA bottom. The SEM micrograph in fig. 4 depicts the surface of one electrode. The surface structure of the thick film electrode differs from the typical thin film topography. The increased roughness as an intrinsic feature of the electrodes leads to a larger surface in contact with the cell medium. The impedance of these thick film electrodes was measured with an RCL meter at 1 kHz using isotonic saline as electrolyte. The median of the ohmic resistance of all 3D electrodes amounts to 5.6 kΩ and those of the capacitance amounts to 2 nF. These values correspond to area correlated values of 0.4 pF/µm² and 1 Ω/µm². Typical values for planar platinum MEA electrodes reach 0.03 pF/µm² and 83.6 Ω/µm² [2]. Thus, thick film electrodes promise better signal/noise ratio as planar electrodes. The first promising results have been achieved using 3D MEAs for 3D cell culture of neurons [3]. It has been demonstrated that a physically connected 3D neural network is built in the MEA which exhibits a richer electrophysiological activity that cannot be found in conventional 2D neural networks and which resembles the one detected in in-vivo measurements.

H. Bartsch1, D. Stöpel1, M. Fischer1, M. Baca2,

J. Müller1, A. Schober2

3D Multi Electrode Arrays

Fig. 2: Output characteristics of a 266 nm channel device

Fig. 1: REM image of a sidegate transistor device

Fig. 3: Cross section of an AlGaN/GaN-based sidegate transistor device


PROCESS TECHNOLOGY

121

Contact

Nanotechnology Group


[1] Ch� Förster, et al�, Mater� Sci� Forum 483-485, 201-204, 2005�

[2] L� Hiller and J� Pezoldt, IEEE Trans� Electron Devices, Bd� 60, Nr� 10, pp� 3047-3052, 2013�

[3] F� Schwierz and J� J� Liou, Solid-State Electron�, Bd� 51, Nr� 8, pp� 1079-1091, 2007�

[4] B. Hähnlein et al., Appl. Phys. Lett., Bd. 101, Nr. 9, p. 093504, 2012.

[5] M� A� Khan et al�, Appl� Phys� Lett�, Bd� 77, Nr� 9, p� 1339, 2000�

We present the realization of sidegate transistor devices based on AlGaN/GaN heterostructures grown on silicon substrates using a SiC transition layer [1]. The growth of AlGaN/GaN heterostructures on Si (111) was performed using metalorganic chemical vapour deposition (MOCVD). Electron Beam Lithography (EBL) was used to structure the T-shaped active region of the TTJ devices. As masking material a CoPMMA/PMMA system of about 400 nm thickness was the resist of choice for the structures above widths in the nanometer scale. For the active part, a 100 nm thick PMMA resist was used solely with a higher acceleration voltage and smaller aperture for the EBL. The etching process was done in an Inductively Coupled Plasma (ICP) chlorine plasma to form the mesas for device isolation. The contacts to the 2DEG were realised with a Ti/Al/Ti/Au system. They were annealed and thus alloyed by Rapid Thermal Processing (RTP) in an argon-hydrogen gas mixture at atmospheric pressure at 825°C. The density of the two dimensional electron gas was 6.7×1012 cm-2 measured with the van der Pauw Hall measurement. Electron mobility was found to be 1520 Vs/cm2 [2].Sidegate transistor devices consist of an in-plane gated channel (Fig.1) wherein a two-dimensional electron gas can

be enhanced or depleted. The dielectric constants have to be distinguished for the influence via air (εr ≈ 1) and via GaN-maerial (εr = 8,9) (Fig.2). Due to the existance of the 2DEG without external fields, the devices act as normally-on transistors. Channels between 80 nm and 266 nm were realised on AlGaN/GaN systems with Al contents of 20 % and 35 %. Transconductances up to 143 mS/mm were achieved. The channels are closed for gate voltages between -5 V and -9 V.Fig.3 shows the output characteristics of a sidegate transistor device, produced in a heterosystem with 20 % Al content. The channel has a width of 266 nm. The distance to the gate is 121 nm. Due to the large gate-channel-distance, disadvantages regarding the control behaviour could be assumed. But, it could be shown that side gates show influence in the same way as high-k and HEMT devices, which could be explained by the gate capacitance [3]. The values of the gate-capacitance reach 8.6x10-8 F/cm2 which is near the values of graphene sidegate devices with 1.6x10-7 F/cm2 [4] or AlGaN/GaN-HEMTs with 3x10-7 F/cm2 [5].

L. Hiller, J. Pezoldt

AlGaN/GaN-based Sidegate Transistor Devices on (111) 3C-SiC/Si pseudo substrates

Fig. 2: Measured and simulated return and insertion losses of the transitions

Fig. 1: Optimized wideband Wire-bond transition in HFSS™

PROCESS TECHNOLOGY

Contact


122

1 Electronics Technology Group2 Electronic Measurement Research Lab3 RF and Microwave Research Group

Funding: German Federal Ministry of Economics and

Technology (BMWi), in the project KERAMIS-GEO

Alexander Schulz | +49 3677 69-3376 | alexander�schulz@tu-ilmenau�de

[1] A. Schulz, T. Welker, N. Gutzeit, D. Stöpel, F. Wollenschläger and J. Müller, “Optimized cavities for microwave applications

using the new low loss LTCC material Du Pont 9k7”, CICMT Conference, Erfurt, Germany, 17 - 19 April 2012

[2] A. Schulz, D. Stöpel, T. Welker, R. Müller, F. Wollenschläger and J. Müller, “Optimized wire-bond transitions for

microwave applications up to 67GHz using the low loss LTCC material DuPont 9k7”, European Microelectronics Packaging

Conference (EMPC), Grenoble, France, 08 - 12 September 2013

Monolithic Microwave Integrated Circuits (MMICs) are typically assembled in small cavities and electrically connected to a carrier substrate using bond wires. This contribution presents a wideband wire-bond transition, working from DC up to 67GHz, which is suitable for multilayer System-in-Package (SiP) and Multi-Chip-Module (MCM) applications, using the Low Temperature Cofired Ceramics (LTCC) material DuPont 9k7V. Bond wires for microwave and millimeter wave signals have to be as short as possible to decrease their inductance, resistance and other parasitic effects caused by discontinuities of the chip to substrate transition. Reducing bond wire lengths is basically limited by manufacturing tolerances of LTCC cavities, assembly tolerances during die-bonding and die-size tolerances. Straight and orthogonal cross sectional LTCC cavity edges have been recently realized by several technological improvements during layer mechanical structuring and lamination [1]. They facilitate a repeatable wire bonding process closer to the cavity rim which reduces the bond wire length significantly.Design optimizations of the wideband wire-bond transition from an aluminium oxide ceramic (Al2O3) test chip to DuPont 9k7V were done using the 3D full wave simulation software

HFSS™ (Ansys, Canonsburg, PA). Grounded coplanar waveguide transmission lines (CPWg) were used on both substrate materials (Fig. 1). Due to the different permittivity values of both materials and the abrupt permittivity change at the interface, the main objective was to maintain the impedance matching along the entire signal path. In addition, design improvements of the transition reduces radiation losses substantially. The standard LTCC process was modified by silicone inlay insertion techniques during lamination [1]. After bonding the Al2O3 test chip into the 3-layer LTCC cavities, an automatic ball-wedge bonder was used to wire-bond the interconnections. A return loss better than -10dB up to 55GHz and a preferable insertion loss <1dB up to 67GHz were achieved during measurements for the ball-wedge wire-bond transition (Fig. 2). Furthermore, the simulation results of the transition seem very promising and could offer a wideband use of up to 90GHz, applying short wedge-wedge bond wires or ribbons. A detailed description of the design improvements and optimizations, the manufacturing process as well as measurement results of the wideband wire-bond transition is a part of the publication [2].

A. Schulz1, D. Stöpel1, T. Welker1, R. Müller2,

F. Wollenschläger3, J. Müller1

An optimized wideband wire-bond transition for microwave applications up to 67GHz using DuPont 9k7

Fig. 2: Sensor and electronics prositoned in the FIB chamber

Fig. 1: Mass sensor with piezoresistive properties

Fig. 3: EBID carbon structure on the mass sensors surface

Fig. 4: Measured frequency shift due to the mass change


PROCESS TECHNOLOGY

123

Contact

Funding: FP7/2007-2013, GA 318804 (SNM)

Micro- and nanoelectronic Systems Group

Manuel Hofer | +49 3677-69-3352 | manuel�hofer@tu-ilmenau�de

[1] Ekinci K� L�, Huang X� MH� and Roukes M� L�, Applied Physics Letters, vol� 84, no� 22, p� 4469, 2004�

[2] Friedli V�, Santschi C�, Michler J�, Hoffmann P� and Utke I�, Applied Physics Letters, vol� 90, no� 5, pp� 053106-3, 2007

[3] Naik A. K., Hanay M. S., Hiebert W. K., Feng X. L. and Roukes M. L., Nature Nanotechnology, vol. 4, no. 7, pp. 4

[4] Ivo W. Rangelow et al., Proc. SPIE. 2879, Micromachining and Microfabrication Process Technology II, 56. (Sept 23, 1996)

doi: 10�1117/12�251232

Small nanoelectromechanical cantilevers as NEMS devices, oscillating at high frequencies, are capable of providing better mass sensitivity when compared to many larger commercially available cantilevers. The goal of this development was to realize sensors capable of achieving a mass resolution comparable to the mass resolution of a mass spectrometer. Nowadays, sensors are able to detect the impact of single atoms[1]. The most common read out method which is applied to measure a mass change is based on the measurement of a shift of the sensors free oscillating resonance frequency. This simple principle of comparing the free oscillating resonance frequency, after a mass change is generated, is well accomplished. Furthermore, knowing the sensitivity of the sensor, the recalculation of the actual mass change is possible. However, during the resent recent years different approaches have been made from different research groups by using different materials with different shaped mass sensors [2-3]. In many cases the mass detection requires sophisticated electronics- and experimental setup, and often they are limited to UHV environment.Here, we present a new approach of a micro- and nano sized silicon based mass cantilever using the piezoresistive quantum-size effect readout [4] to measure its resonance frequency, which is in the order of 5 MHz. Our technology allows fabricating cantilevers with frequencies of up to

120 MHz or higher if needed. The small cantilever is driven externally by a thermal-bimorph or piezo-electrical method. Special PLL electronics and software, developed by nano analytik GmbH, Ilmenau, with wide bandwidth and digital signal filtering allows a continuous (almost real time) measurement of the sensor's resonance frequency. These electronics are capable of detecting the thermo-mechanical oscillations of the cantilever when it is not driven externally. We achieve thermal noise-limited detection of mechanical resonances in these devices at room conditions. A change of the sensors mass is immediately highlighted in the analyses software, where the actual mass change is calculated from the amount of change in frequency and knowing the mass sensitivity. The calibration of the mass sensor showed a mass sensitivity of S=11.31x10-18 g/Hz. Different experiments in air, liquid and vacuum verified the proper field of applications. This new approach of the combination of material, NEMS-cantilever and precise electronics makes it possible to verify in-situ an amount of deposited- and or removed mass of the sensor within an Electron or (Ion) Beam Induced Deposition (E(I)BID) system. We could measure the mass of a carbon deposited mass of 791 zg. Based on the in-situ verification and validation using a Focused Ion Beam tool, a typical field of application of such a sensor is as a mass detection- and/or mass calibration sensor for a FIB tool.

M. Hofer, T. Angelov, I. Atanasov, A. Reum, A. Ahmad,

T. Ivanov, I. W. Rangelow

Attogram Resolution E(I)BID Mass Sensor

Fig. 2: (A) Fabrication of area lighting modules, (B) Area isolation and passivation of assembled LEDs

Fig. 1: Automated reel-to-reel fluidic self-assembly scheme

PROCESS TECHNOLOGY

Contact


124

1 Nanotechnology Group2 University of Minnesota, USA Funding: NSF (DMI-1068013), DFG (JA 1023/3-1), Carl-Zeiss

Heiko Jacobs | +49 3677 69-3723 | [email protected]

[1] S. Park, J. Fang, S. Biswas, M. Mozafari, T. Stauden, H. O. Jacobs, Adv. Mater., 5942-5949 (2014) 26

[2] H. O. Jacobs, A. R. Tao, A. Schewarts, D. H. Gracias, G. M. Whiteside, Science, 323-325 (2002) 296 (5509)

Macroelectronics is a field or research to extend the application range of electronic and optoelectronics devices. In macroelectronics, “larger” is considered better which is in stark contrast to the conventional field of microelectronics where “smaller” and a high function density is the most important driver. In view of the recent trend towards large area integration, traditional methods of robotic pick and place are challenged to integrate functional devices over large areas in an economical fashion. Directed/engineered self-assembly is uniquely suited as a mechanism to solve this challenge. This methodology allows for the redistribution of components over large areas and the ordering of unorganized parts in a massively parallel fashion. For example, a binned container full of semiconductor dies/chiplets of a certain type and quality can be redistributed and assembled at precise locations on a substrate at any desired pitch or required functional density using methods of directed self-assembly [2]. This project studies the implementation of the first automated reel-to-reel fluidic self-assembly system based on surface tension driven self-assembly for macroelectronics application. The reported system incorporates precisely controlled and automated agitation, web moving and component recycling and dispensing system as shown in Figure 1. Furthermore, it enables continuous parallel assembly of semiconductor chips at a high rate (15k chips per hour using 2.5 cm wide web) and assembly yield (>99%) under optimal condition. In principle, scaling to any throughput

should be possible considering the parallel nature of self-assembly. The process overcomes the limitations on area and throughput of prior methods. It provides a new platform for macroelectronics to enable the integration of microscopic high performance inorganic semiconductors on flexible or stretchable substrates with any desired location, pitch, and integration density [1].Figure 2 provides one example where the process is applied to the assembly of LEDs targeting an application in the cost effective production of area lighting modules. First, the LEDs are assembled on the patterned flexible substrate using reel-to-reel system (see fig. 2A). Second, after assembly a UV curable polymer (NOA) is used as a separation layer between top and bottom contact (see fig. 2B). The third step of fabrication procedure is a lamination step whereby the top conductive layer, 7 cm × 7 cm wide gold mesh, is applied [1].

M. Mozafari1, S. Biswas1, S. Park2, J. Fang2, T. Stauden1,

H. O. Jacobs1

Automated reel-to-reel fluidic self-assembly enabling the production of solid state lighting panels

Fig. 2: Bottom view of the ASIC (left). One chip houses 80 low-noise amplifier (right) with two stages

Fig. 1: Concept of the 3D-MEA with 10 sensor elements, 10 needles per sensor element and 8 sensors per tower


PROCESS TECHNOLOGY

125

Contact

Biosignal Processing Group

Funding: 3DNeuroN project in the European Union‘s Seventh

Framework Program, Future and Emerging Technologies, n°296590�

Peter Husar | +49 3677 69-2860 | peter�husar@tu-ilmenau�de

[1] Multi Channel Systems MCS GmbH, „multichannel systems Innovations in Electrophysiology“ Available: http://www.

multichannelsystems.com (2014).

[2] S. Silbernagl, Taschenatlas Physiologie, Stuttgart: Georg Thieme Verlag KG (2012).

The human brain is a flexible system of interacting units. Learning procedures especially involve reorganisation of connections between and specialization of these units. So far the leaning mechanisms are not decoded due to the insufficient knowledge about model details such as the three dimensional structure and adequate representations of neuronal connections.In our present project, 3DNeuronN, we aim to analyze learning processes by observing the neuronal cell organization within real networks.In accordance to the current state of the art, neuronal stem cells are cultivated in micro electrode arrays (MEA). MEAs are culture dishes with integrated planar sensors. The distances between the sensors are smaller than the size of a cell including soma and dendrite. This technique provides a method to measure cell activity of thin cell layers. However, network communications in the third dimension cannot be resolved.In the present project, we cultivate cells in multiple layers to establish three dimensional networks. To measure signals from cells of each layer stack, we designed a three dimensional MEA (3D-MEA). The third dimension is realized

by 1 mm high needles with eight capacitive sensors and up to 10 needles are used to form a sensor element (fig. 1). The stimulation is triggered by 10 of 80 chooseable sensors simultaniously. The stimulation patterns are designed by Fraunhofer Institute for Digital Media Technology (IDMT) to evoke reorganization characterstics of the neuronal network. With the 3D-MEA the three dimensional responses of the cell network will be recorded.The network activity generates small current flows in the micro-ampere range [2] which are measured by the capacitive sensors. Therefore, a signal amplification is needed. To prevent additional noise, the amplifier should be placed as near as possible to the sensors. To achieve a close to signal amplification, the “Institut für Mikroelektronik- und Mechatronik-Systeme gGmbH” in Erfurt (IMMS) developed an application-specific integrated circuit (ASIC). The ASIC includes two low-power and low-noise amplification stages with bandpass characteristics, which is applied to each channel (fig. 2). To increase the three dimensional resolution, multiple numbers of ASICs and sensor elements can be arranged in parallel.

T. Just, P. Husar

Biomimicking the brain - towards 3D neuronal network dynamics

1 Electronics Technology Group2 Micromechanicical Systems Group

Funding: BMBF (project: “NaMiFlu”; 16SV5360)

Sabine Günschmann | +49 3677 69-2782 | [email protected]

[1] M. Fischer, H. Bartsch de Torres, B. Pawlowski, R. Gade, S. Barth, M. Mach, M. Stubenrauch, M. Hoffmann, and J. Müller:

“Silicon on Ceramics – A New Integration Concept for Silicon Devices to LTCC” Journal of Microelectronics and Electronic

Packaging (2009)6; 1-5

IntroductionTo avoid unneeded oil changes on big machines such as hydraulic systems, marine diesel engines or airplane engines when the quality of the oil is still acceptable, a measurement of the real-time oil quality is possible. This also prevents too late oil changes which jeopardize the function of these machines. A microfluidic system usable at high pressures (up to 400 bar) with an integrated oil sensor which ist able to measure the status of lubricating oils is demonstrated. Principle and TechnologyTo detect the contamination and water content of the oil, the change of its infrared transmission spectrum can be measured. For this purpose an IR-Emitter sends infrared light through a measurement cuvette which is filled with the oil. At the backside a detector receives the signal which is evaluated. Thick silicon wafers are used to build the measurement cuvettes because this material has the necessary characteristics, like being transparent in the infrared measurement range to withstand a pressure of up to 400 bar and multiple cuvettes can be manufactured in an array format. For the optimal mechanical stability, the silicon wafers have to be 2 mm thick. However, standard wafer bonding techniques are not applicable for such thick wafers since they have a large wafer bow and are relatively inflexible. For this reason the cuvette is bonded using a LTCC layer and the SiCer-technique [1]. The SiCer-process had to be adapted to the wafer properties and the specific design of the cuvette. For LTCC-to-silicon bonding, nanostructures are created on the wafer surface by using a combined etching process on a STS Multiplex ASE-Tool. These nanostructures have to be short and conic for mechanical stability. For the ideal optical properties of the measurement cuvette, the nanostructures have to be long and acicular. Therefore, it is necessary to produce selective nanostructures on one wafer surface which is realized by lithographic techniques. First

at the front-side of the wafer, a polymer mask with circles is deposited to etch cavities with a deepness of 70 μm. In these cavities optical-type nanostructures are etched (Fig. 1B). Bondable nanostructures are made on the entire area of the back-side of the wafer. These bond needles are protected by a polymer mask which only has openings for the fluidic channels. The channels are deep etched down to a deepness of 70 μm, and subsequently optical nanostructures are made in these channels (Fig. 1A). In the next step a LTCC foil with openings in the channel area is adjusted to the first wafer by using an optical alignment device. Then the second wafer is adjusted, and the sandwich is laminated. The sandwich is burnt out and sintered in a pressure assisted sintering furnace (ATV type PEO 603) at 900°C peak temperature. By this process a quasimonolithic compound substrate is generated which is 4.1 mm thick. Due to this thickness a special saw blade and an adapted sawing process is applied to singulate the individual cuvettes. To avoid microcracks in the silicon, sawing is done in a step by step process with 7 repetitions. Up to 20 cuvettes can be realized on one 4" compound substrate (Fig 1C).

S. Günschmann1, M. Fischer1, L. Müller2, J. Müller1

High pressure microfluidics for real time oil analysis

Fig. 1: A) Silicon Wafer with deep etched fluid channels an selective produced nanostructures B) Wafer top with optical nanostructures C) final single cuvette

PROCESS TECHNOLOGY

Contact


126


PROCESS TECHNOLOGY

127

Contact

1 RF and Microwave Research Group2 Electronics Technology Group

Alexander Ebert | +49 3677 69-1190 | [email protected]

[1] S. Humbla, R. Stephan, D. Stöpel, J. Müller, and M. A. Hein: "Low-Earth-Orbit Verification of a Reconfigurable 4x4 Switch

Matrix and Potential Applications for Satellite Communications, IEEE APWC 2013, DOI: 10�1109/APWC�2013�6624916

[2] S. Kaleem, S. Rentsch, S. Humbla, D. Stöpel, R. Stephan, J. Müller, and M.A. Hein: "Highly integrated reconfigurable

microwave switch matrix module for geostationary communication satellites", European Microwave Conference 2014 and

IEEE Xplore

As part of the public collaborative R&D projects KERAMIS and KERAMIS II ("ceramic microwave circuits for satellite communications", contract numbers 50YB0313 and 50YB0622) a reconfigurable switch matrix was developed for low-earth-orbit space applications using the ceramic multi-layer circuit technology KERAMIS®. Subsequently, the switch matrix was successfully tested and operated in orbit without malfunctions for longer than one year as part of the technology verification payload on a low-earth orbit (LEO) aboard the satellite TET-1 ([1] public R&D-project OK-tech, contract number 50YB1222). Consequently, the highest possible technology readiness level of TRL = 9 for LEO satellite applications was achieved.On the basis of this tremendous design and testing success, the switch matrix has been further revised, modified, optimized and adapted to the specific requirements of a geostationary orbit with a planned minimal lifetime of 15 years. With respect to an increased functional density, the switch matrix has been improved in several key areas, especially from the reliability point of view. These include alternative semiconductor circuit technologies for future microwave devices, more efficient design techniques for multi-layer modules, the exploitation of new hybrid microwave material systems, and the increase of structural

precision on the low-temperature co-fired ceramic substrates. In specific, a redundancy switching concept was developed and integrated into the compact module [2], presently awaiting space qualification testing.The previously separate driver circuits for the PIN-diodes of the switch matrix were integrated into the switch module. Hence, the matching networks had to be arranged in buried layers of the module along with a modification of the microwave circuit, to meet the specific requirements of space applications, for instance, excluding floating electric potentials. Consistent with a technology adapted design, extensive changes to the electrical layout were made, achiev-ing the highest possible quality and reliability. In addition to this increased functionality, the lateral dimensions could be reduced to 32 mm by 32 mm with similarly good microwave performance at the frequency band from 17 to 22 GHz (Ka-band satellite downlink).This work was funded by the German Federal Ministry of Economics and Technology (BMWi) under the project management by the German Aerospace Center (DLR, contract no. 50YB1112, project acronym KERAMIS-Geo).

S. Rentsch1, S. Humbla1, S. Kaleem1, D. Stöpel2,

R. Stephan1, J. Müller2, M. A. Hein1

Highly integrated reconfigurable LTCC switch matrix module for geostationary satellites

Fig. 2: LTCC module generation 4.3 with redundant paths during verification on a test board, component size 32 mm by 32 mm

Fig. 1: Reconfigurable switch matrix module on complete circuit board

1 Nanotechnology Group2 Department of Physics, Universität Paderborn


[1] G. McDaniel, J. W. Lee, et al., J. Vac. Sci. Technol. A 15 (1997) 885-889.

[2] J. J. Wang, E. S. Lambers, et al., Solid-State Electronics, 42 (1998) 2283-2288.

[3] P. Yih, A. J. Steckl, Electrochem. Soc. 140 (1993) 1813-1824.

[4] H. Dimigen, H. Lüthje, Philips Techn. Rev. 35 (1975) 199-208.

[5] L. Hiller, T. Stauden, et al., Mat. Sci. Forum 778-780 (2014) 730-733.

3C-SiC grown on Si substrates allows combining the advantages of SiC with the large area abilities of the silicon technology. Generally, to target micro- and nanoelectronical and mechanical application fields, the formation of controlled surface morphologies or lateral structures with dimensions down to sub 100 nm feature sizes is required. Dry etching techniques are the methods of choice to meet the requirements.In the past, the effect of the temperature, the gas mixture containing reactive gases like SF6, NF3, CHF3, CF4, IBr, BCl3

and Cl2, and O2, Ar or N2 additions on the etching rate of SiC have been investigated [1-3]. 10 µm thick 3C-SiC(100) epitaxial layers grown on 4” Si(100) wafers by Novasic® were used. After cutting, the samples were cleaned. A PMMA based two resist layer system was used. The structures were defined with a Raith 150 EBL system at 20 kV acceleration voltage using a 7.5 µm aperture. The masking material (Ni) was deposited using a LES 250 electron beam evaporation system. The masked samples were etched in an 800 W 2.45 GHz downstream ECR plasma etching tool.The morphology of the mesa structure transforms continuously with increasing hydrogen flow. Without hydrogen addition (Fig. 1 a), the etch profile consists of an anisotropic part on top of the mesa. With increasing etching

depth the side walls develop isotropic like morphology features in form of a slightly elliptic geometry. This effect flattens the steepness of the Mesa sidewalls. At the base of the mesa structure, enhanced erosion occurs, evidenced by a clear micro trench development. The increasing cross section and changing sidewall geometry is caused by the tapering effect [4], due to the side wall reflection of the incident ions. If H2 is added to the reactive gas mixture, the side wall slope increases and the microtrenching reduces continuously. This is demonstrated in Fig 1 b and 1 c. Furthermore, independent of the etching conditions in all cases, residue free 3C-SiC(100) surfaces were obtained.Furthermore, the dependence of the side wall slope on the hydrogen flow rate and the overall system pressure were investigated. The dependencies are shown in Figuress 2 and 3. It can be seen that in a Ar/SF6 gas mixture with 20 sccm Ar, 5 sccm SF6, 0.0006 mbar, bias -200 V and a platen power of 20 W the side wall slope increases with rising hydrogen flow and has a maximum at almost 90 degrees between 0.001 and 0.002 mbar. In contrast, the etching rate decreases with the addition of hydrogen due to the reduction of active fuorine species and charged ions (Fig. 2). In this pressure range, the etching rate with the highest side wall becomes saturated (Fig.3) [5].

L. Hiller1, T. Stauden1, R. Kemper2, D.J. As2, J. Pezoldt1

Hydrogen-Effects in ECR-Etching of 3C-SiC(100) Mesa Structures

Fig. 2: Side wall slope and etching rate vs. hydrogen flow

Fig. 1: Evolution of the mesa morphology as a function of the hydrogen flow (a) 0, (b) 2, (c) 10 sccm

Fig. 3: Side wall slope and etching rate vs. system pressure

PROCESS TECHNOLOGY

Contact


128


PROCESS TECHNOLOGY

129

Contact

1 University of Minnesota, USA2 Nanotechnology Group Funding: NSF Grant DMI-0755995, DFG Grants STA 556/4–1

and JA 1023/4-1

Heiko O. Jacobs | +49 3677 69-3723 | [email protected]

[1] J. Fang, S.-C. Park, L. Schlag, T. Stauden, J. Pezoldt, H. O. Jacobs, Advanced Functional Materials 24(24), 3706-3714,

(2014)

[2] E.-C. Lin, J. Fang, S.-C. Park, T. Stauden, J. Pezoldt, H. O. Jacobs, Advanced Materials 25(26), 3554-3559, (2013)

[3] E.-C. Lin, J. Fang, S.-C. Park, F. W. Johnson, H. O. Jacobs, Nature Communications 4, 1636/1-1636/8, (2013)

Detection of chemical agents in the gas phase has attracted much attention because of the applications and potential for explosives detection and environmental monitoring. The detection of small molecules and airborne species at low concentration commonly requires sensing schemes where the analytes are absorbed on a surface. The process of absorption and precipitation is, therefore, critical to the detection limit of the analytes. This is true for all the established gas-phase sensing concepts. Interestingly, most of the more recently reported sensing schemes aim at increasing the sensitivity to a single molecular level and use diffusion as a mechanism for transport that leads to a collection efficiency of the airborne species, which is not optimized. In other words, it becomes increasingly difficult to detect and capture molecules on the basis of diffusion in cases where the active sensing area is reduced unless the question of localized delivery is addressed. Effective collection on a small sensing area is not possible based on diffusion alone and the employment of a directed force will be required to solve the problem of transport.We introduce a new general approach which uses a corona discharge based analyte charging method in combination with an electrodynamic lens based analyte collection concept to transport airborne analytes to precise points on a surface to improve the response time of existing gas

sensor designs by several orders of magnitude. The process, referred to as “corona/lens-based-collection”, enables us to transport analytes from a space that is centimeters away to specific sensing points on a surface with a minimal spot size approaching 100 nm. The approach is widely applicable demonstrating localized collection of i) microscopic particles (Kentucky blue grass pollen, 20 µm in diameter, ≈3 × 1017 Dalton), ii) inorganic nanoparticles (CdSe nanoparticles, 4 nm in diameter, ≈1.4 × 105 Dalton), all the way down to iii) small organic molecules (Alq3, 459.43 Dalton; anthracene, 178.23 Dalton; benzenethiol, 110.19 Dalton). In all cases we find that the collection rate is several orders of magnitude higher than in the case where the corona/lens-based-collection is turned off and where collection is driven by diffusion only.To demonstrate and quantify how this general strategy improves the response time of an existing gas sensor design, the collection scheme is integrated on an existing SERS based sensor that is sensitive to the adsorption of benzenethiol. We find that SERS signal is enhanced by three orders of magnitudes as a result of increased collection efficiency. In terms of response time, the process is able to detect analytes at 9 ppm (parts per million) within 1 second. As a comparison, 1 hour is required to approach the same signal intensity in the case where diffusion-only-transport is used.

J. Fang1, S.-C. Park1, L. Schlag2, T. Stauden2, J.

Pezoldt2, J. Reiprich2, H. O. Jacobs2

Localized Collection of Airborne Analytes to Improve the Response Time of Existing Gas Sensor Design

Fig. 2: SERS sensor comparing diffusion-only-transport with corona-based analyte collection

Fig. 1: Schematic of advanced analyte transport and collection using corona discharge with an electrodynamic lens

Group for Inorganic-Nonmetallic Materials

Funding: AiF/ZIM/KP: VP2184719CK1, Supported by: Federal

Ministry for Economic Affairs and Energy

Sharon Krenkel | +49 3677 6933-46 | sharon�krenkel@tu-ilmenau�de

[1] A. Hesse, S. Belau, S. Mrotzek, D. Hülsenberg, Fabrication of microstructured glass components by drawing technology,

Biannual Report 2005/2006, Center for Micro- and nanotechnolgies, 2006, S� 118

[2] D. Enke, F. Janowski, W. Schwieger, Porous glasses in the 21st century – a short review, Microporous and Mesoporous

Materials., 2003, 60, 19–30.

Data will be published in Physics and Chemistry of Glasses: European Journal of Glass Science and Technology Part B (2015)

IntroductionFor the fabrication of components with small and long capillaries with μm diameters, the drawing technology is suitable [1]. Such capillaries provide control of flow rate and pressure loss. For the first time, this drawing technique has been applied to produce glass capillaries with a porous matrix, e.g. for sensing and catalysis.A large surface area is produced by the use of Vycor glass. The Vycor process generates a highly porous vitreous SiO2 skeleton with a specific surface area up to 500 m²/g and pores in the range of 2 to 150 nm [2]. The combination of the drawing technology with self-organized porous material leads to a hierarchical pore structure of μm- and nm- pores.Technology and MaterialSodium-borosilicate glasses are used as preform. At certain temperatures the glasses tend to spinodal decomposition into a silicate and borate rich phase. The borate phase can be removed by selective extraction. The pore size and pore volume can be adjusted [2]. The preform glasses are used in the form of tubes and rods. For the formation of the final structure, they are stacked together and fixed in a holder. To reduce the borate evaporation, the bundle was impregnated with borax solution before drawing. The final geometry is determined by temperature as well as the drawing und feeding velocity. The development of nano-porous systems in the glass walls was realized through a secondary process. This process includes heat treatment (550°C - 700°C, 24 h), acid (1M HCl, 90°C, 24 h) and basic (0,5M NaOH, RT, 1 h) extraction.

ExperimentThe best drawing conditions for a homogeneous process have been found to be: temperature around 740°C, vfeed= 5 mm/min and vdraw > 40 mm/min. Figure 1 shows a monolith drawn at 740°C, vfeed=5 mm/min and vdraw=150 mm/min. Two μm pore types are recognized: pores in the range of 70 to 110 μm (gores) and pores between 435 and 490 µm (inner diameter of the tubes). Inside the oven, we distinguish two zones: the phase separation zone (500°C - 720°C) and dissolution zone (> 720°C). The control of the microstructure during the process is feasible but complex and only possible for certain parameters. To suppress the phase separation, the process temperature is set to Tmax = 740°C. The generation of the nanometer pores in the glass itself was carried out via a second heat-treatment step, independent of the drawing process. Figure 2 shows the monolith extracted with a recognizable uniform porous structure within the volume. The meso pore dimensions lied in the range of 56 nm. The formation of smaller pores in the external layer was detected by mercury intrusion measurements (Figure 3). Currently, “transport pores” (μm pores) in the range from 5000 μm to 30 μm and “functional pores” (nm pores) between of 10 to 150 nm can be produced, independent of the final geometry.

S. Krenkel, E. Rädlein,

Manufacturing of highly porous, anisotropic glass monoliths

Fig. 2: nm pores at the edge of the monolith (SE (M), 5kV)

Fig. 1: Bundle of 19 tubes after drawing and extraction (μm-pores)

Fig. 3: Presentation of the relative and specific pore volume depending on the pore diameter

PROCESS TECHNOLOGY

Contact


130

Fig. 1: a) Schematic drawing of the system combining EBL, SPL, plus AFM for inspection; b) Concept of negative-tone EBL & positive-tone SPL mix & match lithography; c) Results [2, 3]


PROCESS TECHNOLOGY

131

Contact


Funding: FP7/2007-2013 under Grant Agreement No� 318804

(acronym SNM - Single Nanometer Manufacturing for beyond

CMOS devices) and SFB 622

Marcus Kästner | +493677-69-1589 | [email protected]

[1] Kaestner, M., and Rangelow, I. W., Microelectron. Eng. 97, 96 -99 (2012).


[3] Kaestner, M., Hofer, M., and Rangelow, I. W., Proc. SPIE 8680, 868019 (2013).

[4] Durrani, Z�, Jones, M�, Kaestner, M�, Hofer, M�, Guliyev, E�, Ahmad, A�, Ivanov, Tzv�, Zoellner, J�-P�, andRangelow, I�W�,

Proc. SPIE – Int. Soc. Opt. Eng. 8680, 868017 (2013).

Going “beyond the CMOS information-processing era,” taking advantage of quantum effects occurring at sub-10-nm level, requires novel device concepts and associated fabrication technologies. In the lithographic community immense efforts are being made to develop extreme ultra-violet lithography (EUVL) and multiple-e-beam direct-write systems as possible successors for next generation lithography (NGL). The economically-driven challenge affecting the lithographic technologies comprises the marriage of down-scaling the device-relevant feature size towards single-nanometer resolution with a simultaneous increase of their throughput capabilities. However, the resolution versus throughput evolution reveals that Tennant’s law is still valid - patterning at ultra-high resolution costs time, in detail, the throughput scales with resolution of power to five, which means an improvement of resolution by a factor of 2 will decrease the throughput by a factor of 32.Mix-and-match lithographic strategies are one promising path to break through this trade-off by using a data splitting strategy, which means that all big features are patterned by conventional lithographic methods (optical or electron beam lithography), and only the small features at critical dimension level are patterned by ultra-high resolution scanning probe lithography (Fig. 1).Herein, we have recently demonstrated proof-of-concept combining electron beam lithography (EBL) with the capabilities of closed-loop electric field current-controlled SPL. This combination, whereby also extreme ultraviolet lithography (EUVL) is possible instead of EBL, enables more: improved patterning resolution and reproducibility in combination with excellent overlay alignment and placement accuracy down to single digit nano level. Furthermore, the symbiosis between EBL (EUVL) and SPL expands the process window of EBL (EUVL) beyond the state of the art, allowing SPL-based pre- and post-patterning of EBL (EUVL) written features at critical dimension level with scanning probe microscopy-based pattern overlay alignment capability.

M. Kaestner, M. Hofer, I. W. Rangelow

Mix & Match Scanning Probe and Electron Beam Lithography: High Resolution at Enhanced Throughput

Fig. 2: SEM images of nanoparticle arrays with different dimensions and periods

Fig. 1: Schematic outline and SEM image of the fabrication processes for ordered nanoparticle arrays

PROCESS TECHNOLOGY

Contact


132


Funding: European Research Council (ThreeDsurface: 240144),

BMBF (ZIK-3DNanoDevice: 03Z1MN11)


[1] Z. B. Zhan, Y. Lei, ACS Nano 8, 3862 (2014).

[2] Y. Lei, S. Yang, M. Wu, G. Wilde, Chem. Soc. Rev. 40, 1247 (2011).

[3] Y. Lei, W. Cai, G. Wilde, Prog. Mater. Sci. 52, 465 (2007).

Production of perfectly ordered arrays of nanoparticles with sizes under 100 nm on large area substrates has attracted much attention for various applications in nanotechnology, such as photoelectrical devices, data storage and biological sensors[1-3]. Up to now, it is only the lithographic method that can practically produce nanoparticles with ideal regularity on relatively large areas, such as electron beam lithography, focused ion beam lithography or nanoimprint lithography [2,3]. However, highly specialized lithographic facilities are complex and expensive, and tedious preparation and implementation steps (lithography and lift-off) require accuracy and are time consuming. As a cost-effective surface nano-patterning approach to fabricate large-scale arrays of highly defined nanostructures, anodic alumina, a typical self-ordered nanochannel material formed by anodization of Al, has been extensively explored as a template material for synthesis of multifunctional nanostructures in a wide range of materials [2,3]. Based on the pioneering works by Masuda, Gosele, et al., it is possible to prepare highly ordered anodic alumina via prepatterning Al surface prior to the anodization process to guide the growth of the nanopores. However, transferring this regular pattern on substrate and using it as the template to fabricate ideally ordered nanostructures with tunable and uniform dimensions under 100 nm on large area has not, to our knowledge, been previously reported, which has restricted the application of alumina membranes.

By combining nanoimprinting with ultrathin alumina membrane (UTAM) technique, we presented here a non-lithographic patterning method to fabricate perfectly ordered nanoparticle arrays with tunable and uniform dimensions under 100 nm on various kinds of substrates [1]. To our knowledge, it is challenging even for specialized lithographic approaches in this scale. In our novel approach, UTAM was intactly transferred, for the first time, in different solutions without the supporting of any organic layer such as PMMA (polymethylmethacrylate), which is essential for the fabrication of ideally regular nanoparticle arrays because it thoroughly solves the problems of nonuniform dimension and contamination resulting from the use of organic layer. Due to the reuse of the imprinting stamps and unneeded lithographic process and clean-room facilities, this method offers attractive advantages, such as high throughput, cost-effectiveness, flexibility in controlling nanoparticle dimension and spacing parameters, materials and substrate universality, and massively parallel production, which may overcome problems of low throughput and high cost in the conventional nanolithographic technique, and offer an economical alternative to fabricate various ordered nanostructures for future nano-devices.

Z. B. Zhan and Y. Lei

Nonlithographic route for ordered nanoparticle arrays with tunable and uniform dimensions

Fig. 2: Demonstrator setup with the SiCer RF-MEMS-PlatformFig. 1: a) Process steps to manufacture the RF-MEMS-Platform, b) LTE receiver system overview


PROCESS TECHNOLOGY

133

Contact

1 Electronics Technology Group2 Micromechanical Systems Group3 Electronic Circuits and Systems Group

Funding: DFG - German Research Foundation, Grant no�:

group 1522

Michael Fischer | +49 3677 69-3413 | [email protected]

[1] M. Fischer, T. Mache, B. Pawlowski, D. Schabbel and J. Müller, SiCer - A substrate to combine ceramic and silicon based

micro systems, 2012 IMAPS/ACerS 8th International Conference and Exhibition on Ceramic Interconnect and Ceramic

Microsystems Technologies (CICMT), April 16 -19, 2012, Erfurt, Germany

For the manufacturing of RF components, different substrate materials are used depending on the particular application. Because of the outstanding dielectric properties, ceramic is used for passive components (inductors), functional groups (filters) and circuit boards. Moving RF components (switches) as well as electronic RF components (SAW) are realized with semiconductor substrates. The limiting element in ceramic technology (LTCC) is the achievable geometrical resolution. Because of their surface and material properties, semiconductors (CMOS, MEMS) allow the use of thin-film technology (higher lateral resolutions than LTCC), but they have generally worse dielectric properties than ceramic. We present a RF-MEMS-Platform (Fig. 1a) that allows combining the advantages of both substrate classes by reducing the assembly effort. The quasi-monolithic substrate, based on the SiCer technology concept [1], can be manufactured by standard LTCC and MEMS technologies. The RF wiring can be provided in the ceramic layer due to the better

dielectric properties. Micro mechanical structures such as moving elements and solid state hinges are realized in the silicon layer . Fig. 1b shows the analog front-end of a receiver path for LTE applications. The chain consists of passive blocks (switches, SAW and BAW filters) to separate the different frequencies received. Active blocks like low noise amplifiers (LNA), mixer, voltage-controlled oscillator (VCO), band-pass filter (BP) and variable-gain amplifier (VGA) are included to adjust level and frequency of the received signal to the specification of the analog-to-digital converter (ADC). A high frequency capable SiCer platform enables a multi-physical implementation. Thus, advantages such as minimum insertion loss, high linearity and very low power consumption provided by mechanical switches over transistors can be utilized. Coils within the LTCC offer very high quality factors. In addition, the combination of all microelectronic and mechanic blocks within the SiCer platform provides very short signal paths (Fig. 2).

M. Fischer1, S. Gropp2, J. Nowak3, R. Sommer3, M.

Hoffmann2, J. Müller1

RF-MEMS-Platform based on Silicon-Ceramic-Composite-Substrates

1 Electronics Technology Group2 RF and Microwave Research Group Funding: German Aerospace Center (DLR, no. 50YB0622)

Dirk Stöpel | +49 3677 69-3430 | dirk�stoepel@tu-ilmenau�de

[1] D. Stöpel, K.-H. Drüe, S. Humbla, M. Mach, T. Mache, A. Rebs, G. Reppe, G. Vogt, M. Hein, and J. Müller, "Fine-Line

Structuring of Microwave Components on LTCC Substrates", ESTC, Berlin, 2010.

[2] D. Stöpel, K.-H. Drüe, S. Humbla, T. Mache, A. Rebs, G. Reppe, A. Schulz, G. Vogt, M. Hein, and J. Müller, “Fine-Line

Structuring of Microwave Components on LTCC Substrates”, IMAPS/ACerS 8th International Conference and Exhibition on

Ceramic Interconnect and Ceramic Microsystems Technologies (CICMT), 2012.

Resinate pastes consist of metallo-organic noble metal compounds (e.g. Au, Ag, Pt), which are dissolved in organic suspensions. Long before printed conductors were applied in electronics, resinate pastes were used to decorate porcelain and glass. It can be considered as the origin of thickfilm technology. Today, a wide range of different metal contents and viscosities is available. Typically, the conductor is gold with a content of 10 to 22 %. Resinates contain no glass compounds, so other additives may be used as bonding agents. Standard screen printing is the predominant method to apply the paste over the entire substrate area. Metal content and screen printing parameters define the final metallization thickness and thus the conductivity. The high organic content of the resinates is the reason for a final thickness close to values usually achieved in thinfilm processes (e.g. PVD). Depending on the screens theoretical paste volume, a final thickness from 100 to 300 nm is achieved with Heraeus Au 181208-15. The corresponding sheet resistance is 300 to 150 mΩ/sq.A semi-additive process will provide better conductivity while maintaining excellent resolution [1]. The metallization of the sintered resinate paste is used as a seed layer in a selective

electroplating process. This technology exclusively enables structuring on sintered surfaces, since photolithography in conjunction with galvanic and wet-chemical etching processes cannot be applied on green ceramic sheets.To implement buried fine structures, tape-on-substrate technology is available for laminating and subsequent sintering of structured green sheets on a sintered ceramic. In order to achieve flat substrates and to prevent delamination, the substrate has to be fired using pressure-assisted sintering (PAS). PAS uses uniaxial pressures of about 3 kN during sintering [2].For demonstrating the reproducibly of the high structural resolution resinate technology, circular structures, which are difficult to produce, are manufactured. The attained result is depicted in Fig. 1. With a polymer film mask, 25 μm lines and spaces buried in DuPont 951 were achieved using standard low-cost thick-film equipment. As a technology demonstrator, a band-pass filter is designed and manufactured using DuPont 951 (Fig. 2). The smallest dimensions of the device are 40 µm for lines and spaces. They are achieved with excellent repeatability.

D. Stöpel1, K.-H. Drüe1, S. Humbla2, T. Mache1, G. Vogt2,

M. Hein2, J. Müller1

Resinate Pastes for Electronic Components on LTCC Substrates

Fig. 2: Comparison of simulated and measured filter curves for the buried edge coupled filter using the ToS-technology

Fig. 1: X-ray image of a buried high resolution spiral in DuPont 951 with 25 μm lines and spaces

PROCESS TECHNOLOGY

Contact


134


PROCESS TECHNOLOGY

135

Contact

1 Electronics Technology Group2 Electrochemistry and Electroplating Group

Funding: Thuringian Ministry of Culture under contract

B514-09026

Michael Fischer | +49 3677 69-3413 | [email protected]

[1] M. Fischer, T. Mache, B. Pawlowski, D. Schabbel and J. Müller: SiCer - A substrate to combine ceramic and silicon based

micro systems, 2012 IMAPS/ACerS 8th International Conference and Exhibition on Ceramic Interconnect and Ceramic

Microsystems Technologies (CICMT), April 16 -19, 2012, Erfurt, Germany

IntroductionThe application of nano effects and structures such as nano wires, carbon nano tubes, thin film nano porosity etc. in micro electro mechanical systems (MEMS) requires the fabrication of intelligent and robust connections (electrical, fluidical, thermal) to a manageable carrier system or a PCB. These functions are enabled by the use of SiCer substrates. Back-end processes, such as assembly and the crucial part of packaging (chip bonding, contacting), take place before any micro or nano structuring is made. Thus, the influence of these processes on the sensitive structures can be minimized. The wafer-shaped substrate can be processed utilizing standard MEMS technologies. The monolithic compound is fabricated by using lamination and pressure assisted firing of a nano patterned silicon wafer in combination with a low temperature cofired ceramic tape (LTCC). LTCC functionalities such as electrical and thermal vias, passives, fluidic channels, etc. can be pre-processed using conventional LTCC technology. The silicon layer can be fabricated as thin as necessary for the desired function whereas the insulating LTCC layer ensures the mechanical stability of the SiCer wafer and provides electrical interconnects and embedded components. Fig. 1 shows the SiCer process flow.Technological Aspects and PropertiesGenerally, the ceramic layer of the SiCer consists of several pre-processed LTCC tapes. With standard technologies such

as punching of micro holes and screen printing of pastes (metals, inductors, resistors, capacitors, etc.) as well as several cutting technologies (laser, punching) a back side wiring, electrical and thermal vias, passive devices, cavities or fluidic channels can be processed in the ceramic layers. Trough Silicon Vias (TSV) can be connected with vias or conducting lines in the LTCC. However, for bonding of pre-processed silicon (e. g. wafer with etched trough holes) and LTCC laminates, it is necessary to precisely align (+/- 5 μm) a thin and inflexible silicon wafer with a flexible, wafer shaped LTCC tape stack. For this purpose, an optical alignment and stacking machine with a vacuum gripper for diverse substrate textures was developed in cooperation with Fraunhofer IOF Jena to achieve these requirements (Fig.2). After sintering, the vias of the ceramic layer can be used as back side contact for via filling by electroplating (Fig.3).The connection between silicon and the LTCC is very robust and gas tight. Generally, the SiCer substrate is stable at high temperatures, depending on the used metal system. No delamination or deformation of a standard SiCer substrate was observed after a 30 min thermal stress test at 1000°C. It is possible to adjust the thermal behavior of the whole SiCer substrate by introducing thermal metal vias in the LTCC layer and the separation of single silicon areas by deep reactive ion etching.

M. Fischer1, T. Mache2, J. Müller1

SiCer - A substrate to combine ceramic and silicon based micro systems

Fig. 3: TSV (20 µm) filled by gold electroplating

Fig. 2: Optical alignment and stacking device

Fig. 1: Typical SiCer process flow

1 Electronics Technology Group2 Group for Inorganic-Nonmetallic Materials

Heike Bartsch | +49 3677 69 3440 | [email protected]

[1] Rydosz A, Maziarz W, Pisarkiewicz T, Bartsch H, Müller J: A Micropreconcentrator Design Using LTCC Technology for

Acetone Detection Applications, IEEE Sensors Journal (13) 2013, 1889-1896

[2] Goj B, Brokmann U, Bartsch H, Rädlein E, Müller J: , thin-film capable ceramics for humidity and temperature sensing

applications, 58th ILMENAU SCIENTIFIC COLLOQUIUM, Technische Universität Ilmenau, 08 – 12 September 2014

[3] URN: urn:nbn:gbv:ilm1-2014iwk:3

MotivationLTCC (Low Temperature Cofired Ceramics) are typically used as reliable circuit substrates for RF applications and multilayer systems. Conductor paths are printed on the ceramic green tapes, which are subsequently stacked and fired to achieve a ceramic circuit board with excellent temperature and chemical stability. Hence, these multilayers are used for the assembly of gas analysis systems, for example in acetone analytics [1]. An example for such a gas sensor is depicted in fig. 1. The component consists of a heater and an interdigital capacitor. The dielectric of the capacitor is sensitive to acetone. Its sensitivity depends significantly on the resolution of the interdigital structure, which is limited by the rough ceramic surface. Moreover, a smoother ceramic surface improves the specific resistance of the sensitive layer. This work focuses on the use of sol gel layers for smoothing purposes, which complements the strategy of using screen printed overglaze layers.

ProcessA filled sol gel blend, which contains fused silica particles with a grain size of 40 nm, is spin coated on cleaned LTCC substrates. The roughness (Ra) of the untreated substrates amounts to 120 nm. The sol gel mixture is spin coated on the surface and centrifuged at 1000 rpm. Subsequently, the layer is dried in a climatic chamber at room temperature, and the humidity is reduced from 100% to 30% within one week. Fig. 2 shows a line scan of a ceramic substrate with sol gel layer made with a Laser Scanning Microscope, which captures both surfaces at the same time. Through the transparent sol gel layer, the initial roughness of the ceramic is detectable. A second intensity peak represents the sol gel layer surface and demonstrates its smoothing. Tactile measurements have proven a roughness (Ra) of the coated substrates of 12 nm with a standard deviation of 6 nm. These promising results open the door for a new integration concept for sensor packages.

H. Bartsch1, U. Brockmann2, R. Weiß1, E. Rädlein2,

J. Müller1

Sol gel layer used for the smoothing of LTCC ceramic substrates

Fig. 2: Laser scanning microscope plot of the sol gel and the ceramic surface: the surface smoothing is clearly seen

Fig. 1: Acetone sensor with integrated heater: the refinement of the interdigital structure effects a higher sensitivity

PROCESS TECHNOLOGY

Contact


136

Fig. 2: Single thin film strain gauge on LTCCFig. 1: Overview of the strain gauge array


PROCESS TECHNOLOGY

137

Contact

Electronics Technology Group

Funding: BMBF, Project Optimi II

Nam Gutzeit | +49 3677 69-3453 | nam�gutzeit@tu-ilmenau�de

[1] N. Gutzeit, J. Müller, C. Reinlein, S. Gebhardt, International Journal of Applied Ceramic Technology, Volume 10, Issue 3,

May/June 2013, Pages: 435–442

[2] Gutzeit, Nam; Appelfelder, Michael; Reinlein, Claudia; Fischer, Michael; Müller, Jens, Proceedings MikroSystemTechnik

Kongress 2013, 14.-16. Oktober 2013

High power lasers can be used for an efficient material processing. Within the project Optimi II, deformable mirrors for the correction of the wavefront of a high power laser were investigated together with the Fraunhofer IOF, Jena. This mirror is based on a 220 μm thin LTCC membrane with integrated temperature sensors and heaters and a diameter of 52 mm [1]. For an efficient correction of the wavefront, the mirror is deformed by PZT thick-film actuators on the membranes rear surface. Because of the hysteresis of these PZT actuators, the deformation of the membrane and the geometry of the surface must be observed constantly. This can be done by sensitive CrNi thin-film strain gauges. To monitor the entire surface of the membrane, an array of 160 strain gauges in 40 interconnected groups is integrated [2]. The thin film strain gauges were deposited in cooperation with Siegert TFT GmbH, Hermsdorf.Before the sensitive thin film strain gauges can be sputtered,

the LTCC membrane must be polished to reduce the roughness of the membranes front surface. In Figure 1 the array of the strain gauges is illustrated. The functional part of the CrNi meander has a width of 36 μm and a thickness of 200 nm. The electrical measuring lines were covered with a sputtered gold layer of a thickness of 1.8 μm to minimize their resistance. Figure 2 shows one CrNi meander.During the polishing process alumina grains are pulled out of the glassy matrix of the LTCC membrane. Despite this influence on the surface quality, the strain gauges show a very good homogeneity of the electrical resistance. After the deposition and the lithographic structuring of the functional metallic films, an isolating cover layer is deposited. This 600 nm thick cover layer consists of several silicon nitride and silicon oxide layers.The array of the CrNi strain gauges on the polished LTCC membrane offers a good opportunity to measure the surface geometry of the deformable mirror.

N. Gutzeit, M. Fischer, J. Müller

Thin film strain gauges on LTCC membranes

Micro- and nanoelectronic Systems Group Funding: FP7/2007-2013, GA 318804 (SNM)

Marcus Kästner |+493677-69-1589 | [email protected]

[1] Durrani, Z�, Jones, M�, Kaestner, M�, Hofer, M�, Guliyev, E�, Ahmad, A�, Ivanov, Tzv�, Zoellner, J�-P�, and Rangelow, I�W�,

Proc. SPIE – Int. Soc. Opt. Eng. 8680, 868017 (2013).

[2] Kaestner, M., and Rangelow, I.W., Microelectron. Eng. 97, 96 -99 (2012).


[4] Kaestner, M., Rangelow, I.W., et. al., Proc. SPIE – Int. Soc. Opt. Eng. 9049, 90490C (2014).

Sub-5 nm processing technology, so called Single Nanometer Manufacturing (SNM) technology, represents the next key technology to enable the practical application of quantum-effect devices, such as room temperature single electron and quantum-dot devices [1]. The European project called “Single Nanometer Manufacturing for beyond CMOS devices (www.snm-project.eu)” is targeting this development of novel manufacturing technologies for devices at the single nanometer scale, reaching the theoretical limit of future nanoelectronic and nanomechanical systems.Herein, scanning probe based technologies are the backbone of the SNM project to achieve highest resolution lithography with required alignment and stitching capabilities. We have developed a versatile scanning probe lithography (SPL) platform (Fig. 1) in which self-actuated, piezoresistive cantilevers with conductive tips are used for ultra-high resolution electric field based writing of nano-features. The thermal actuator and the piezoresistive read-out sensor are integrated on the cantilever itself . Thus, neither an external cantilever actuation source nor an external deflection sensor is required for the construction of the SPL system.The lithographic process itself is characterized by a positive-tone,

development-less patterning scheme of molecular resists using a highly confined electric field, current-controlled scanning probe lithography scheme. Sub-5 nm patterning capabilities for line and dot features could be recently demonstrated (Fig. 2). This process, wherein no development step is required, enables a closed loop lithography scheme in which the patterned features are inspected directly after lithography by using the same tool in reading (AFM) mode. In addition, the AFM read-back capability of the set-up is applied for overlay alignment with previously patterned features as well as for stitching of writing fields.Owing to highly promising merits of SPL, like: (1) Capability of closed-loop lithography, including pre-imaging, overlay alignment, and post-imaging for feature inspection; (2) Capability of sub-5-nm lithographic resolution with sub-nm line edge roughness; (3) Overlay alignment and stitching accuracy close to atomic level; (4) Ease-of-use and relatively low costs of ownership, SPL is a promising nano-tool for rapid nanoscale prototyping targeting novel beyond CMOS device, nanophotonic and NEMS system applications as well as high resolution nanoimprint lithography template fabrication.

M. Kästner, M. Budden, Y. Krivoshapkina, H. Lipowicz,

T. Angelov, A. Ahmad, S. Lenk, A. Reum, K. Sozstak,

I. Atanasov, M. Holz, Tz. Ivanov, I. W. Rangelow

Ultra-High Resolution Electric Field Scanning Probe Lithography for beyond CMOS device fabrication

Fig. 2: SEM image of patterned sub-5 nm lines and AFM topography images of single electron device-like features [1, 3]

Fig. 1: a) Scanning Probe Lithography system; b & c) SEM image of self-actuating, piezoresistive cantilever with conductive tip [4]

PROCESS TECHNOLOGY

Contact


138


PROCESS TECHNOLOGY

139

Contact

1 Institute of Process Measurement and Sensor Technology2 Micro- and nanoelectronic Systems Group Funding: Federal Ministry of Education and Research under

contract 03V0235

Ingo Ortlepp | +49 3677 69-5083 | ingo�ortlepp@tu-ilmenau�de

[1] Büchner, H�-J� et al: An optical standing-wave interferometer for displacement measurements� In: Meas� Sci� Technol�

2013

[2] Mandryka, V.: Entwicklung, Aufbau und Untersuchung eines Stehende-Wellen-Interferometers, Doctoral thesis,

Technische Universität Ilmenau

[3] Sternkopf, C. et al: Frequency stabilization of an external-cavity diode laser by offset frequency looking to a stabilized

He-Ne laser� In: Proc� SPIE 9134, 2014

IntroductionIn the field of length measurement with high accuracy and high resolution, interferometric measurement principles are of great importance. But due to their complex set-up, conventional interferometers are expensive and their miniaturisation is limited.Sensors for Standing-Wave-Interferometry enable a completely new concept for interferometers. As standing-wave interferometer heads only consist of a mirror, two photo sensors and a collimator (fig.1), they allow easy alignment, small design and inexpensive mass production.Functional Principle and Measurement ResultsWhen a laser beam is reflected by a mirror, incident and reflected beam interfere in opposite directions and form an optical standing wave with a stationary profile of intensity, whose phase is coupled to the reflective surface. The intensity profile can be detected by a photo sensor, which for this purpose has to be transparent and thinner than the optical wavelength [1]. When either the mirror or the sensor is moved along the optical axis, a pulsating photocurrent will occur. To recognize the moving direction, a second photo sensor has to be placed in the optical path.The transparent photo sensors are carried out as lateral p-i-n photo diode with a striped doping pattern (fig.2). The active area is in the size of the laser beam (app. 1x1mm2). The doped stripes are about w = 10 µm broad. When illuminated, charge carriers are generated in the i-zone and transported

to the p- and n-zones, resulting in a photo current propor-tional to the intensity.It has been shown that the lateral structure has a significantly less device capacity and thus a better dynamic compared to a vertically stacked p-i-n layer diode [2]. When illuminating the sensors with a modulated laser diode, cut-off-frequencies up to 70 MHz were achieved. For a laser wavelength of λ=633 nm, this corresponds to a measuring velocity of 19 m/s, opening up new fields of application for interfero-metric length measurements.A challenging attribute of the sensors is the ultrathin photoactive membrane. For the best compromise between overall signal strength, signal contrast and optical transpar-ency, the thickness has to be d = λ/4n, which is app. 40 nm for λ=633 nm and n=3.8 (silicon). In addition to that, the planarity error must not exceed λ/2 (depending on the actual form deviation) since in this case the sensor signal would vanish. For an acceptable signal contrast and low offset, maximum planarity error is λ/4, which requires bonding the membrane to a glass substrate to be accomplished. With the bonding technology used in this project, a planarity of 180 nm could be attained. For setting up the Standing-Wave interferometer, a He-Ne laser was used as coherent light source in the first instance. In the course of downsizing the entire system, the application of externally stabilised diode lasers is also investigated [3].

H. - J. Büchner1, M. Hofer2, T. Ivanov2, K. Ivanova2, E. Manske1,

I. Ortlepp1, I. W. Rangelow2, J.-P. Zöllner2

Ultra-Thin Photodiode for Standing-Wave Interferometry

Fig. 2: Lateral p-i-n photo diode with a striped doping pattern: cross section (left) and top view (right).

Fig. 1: Complexity of Standing-Wave-Interferometer (left) compared to industrial implementation of Michelson-Interferometer (right)


Funding: European Union (EFRE) and Freistaat Thüringen

(B714-09060 and B714-10048)

Hannes Mehner | +49 3677 69-1860 | hannes�mehner@tu-ilmenau�de

[1] H. Mehner, S. Leopold, M. Hoffmann, J. of Micromech. and Microeng. 23 (2013).

[2] H. Mehner, S. Leopold, M. Hoffmann, Proc. Mikrosystemtechnik Kongress, Aachen: VDE Verlag (2013).

Thin aluminum nitride (AlN) films are used in numerous microelectromechanical systems (MEMS) research fields since the material characteristics allow for multiple applications as RF MEMS, optical MEMS or micro energy harvesting. AlN films show typically an extensive stress gradient in case they are generated by a reactive sputter process. The stress gradient - a non-uniform stress distribution along the film height - results in a deflection of released free standing micro structures. This is usually unwanted since it influences the device behavior respectively can prohibit the basic functionality. The stress gradient is caused by varying lattice parameters and hence non-constant lattice forces along the film height as a result of the material growth during the sputter process.For the first time, significant influence parameters on the stress gradient are identified and varied during the deposition process [1, 2]. The defined variation of the stress gradient by ramping of process parameters has been achieved and the controlled avoidance as well as the controlled generation of positive and negative gradients is shown (fig. 3). The process power induced in the plasma (fig. 3 nr. 1) and the gas flow ratio of the sputter gases argon and nitrogen (fig. 3 nr. 2) are the two major parameters for controlling the stress gradient in thin AlN films. By utilizing a ramping of these parameters the varying lattice forces resulting from the inhomogeneous crystal growth of AlN can be compensated

by a corresponding opposite film stress.Films with a thickness of approximately 450 nm were deposited in a reactive DC-pulsed sputter process on silicon wafers. The stress gradient was investigated by analysis of released one-side clamped cantilever test structures (fig. 1 and fig. 2).It was shown that the intrinsic stress gradient of two films fabricated right after each other is reproducible and varies in the range of 2 – 15% (fig. 3 nr. 0a & nr. 0b). For a film thickness of 450 nm the stress gradient was varied in a range between +1100 MPa/µm (fig. 3 nr. 3) and -1100 MPa/µm (fig. 3 nr. 4). Thin films with a negligible stress gradient were fabricated (fig. 1) by shifting the gas ratio towards nitrogen majority respectively decreasing the plasma induced power during the process. Decreasing the substrate temperature during the process leads to an increased stress gradient caused by a decreased sorting mobility of sputtered particles on the substrate surface. If a variation of process parameters during the sputter process is unwanted or inapplicable, the stress gradient can be influenced by utilizing a post-treatment in form of an annealing step (fig. 3 nr. 5).The experiments were done with AlN, but it can be assumed that process parameter ramping affects the stress gradient of other nanocrystalline materials fabricated by a reactive sputter process as well.

H. Mehner, S. Leopold, M. Hoffmann

Variation of the intrinsic stress gradient in thin aluminum nitride films

Fig. 2: SEM pict. of fig. 1 nr.0a - positive stress gradient

Fig. 1: SEM pict.of fig. 1 nr.2 - stress gradient near zero

Fig. 3: Variation of the intrinsic stress gradient of thin AlN films utilizing different parameter ramps during deposition process

PROCESS TECHNOLOGY

Contact


140

Fig. 2: Comparison of predictors (reflected power: green, path-way: blue) and actual absorption enhancement (FDTD: red) for N=10

Fig. 1: Profile characterized by the sequence 10011010 with block height hλd and width lλd given in multiples of the design wavelength λd.


141

Contact

DESIGN & SIMULATION

Funding: Thuringian Graduate Research School for

Photovoltaics „PhotoGrad“

Group for Theoretical Physics I

Jan Marc Stockschläder | +49 3677 69-3644 | [email protected]

[1] A. F. Oskooi, D. Roundy, M. Ibanescu, P. Bermel, J. D. Joannopoulos, S. G. Johnson , Comp. Phys. Comm. 181, 687 (2010)

Structured metallic back-plane reflector can improve the efficiency of ultra-thin solar cells considerably: Photons that have not been absorbed in the active medium are reflected back into the absorber, preferentially at an increased incidence angle. This raises the question how to optimize the back-plane profile of the solar cell. In principle, modern optimization methods combined with state-of-the-art computational electrodynamics allow us to tackle this challenge. However, reliable easy-to-evaluate predictors for the efficiency of a solar cell with a given profile as back-plane reflector would not only dramatically reduce the computational optimization costs but also contribute to a better understanding of the underlying mechanisms.We developed a semi-analytical criterion for identifying, at negligible numerical cost, promising profiles for a metallic back-plane reflector of ultra-thin solar cells: Many structures with a high value of the “total internal reflected power" Itot at a given design wavelength λd show, indeed, in full numerical calculations a large absorption enhancement. In particular, we studied infinite periodic phase gratings with a grating substructure based on a digital sequence am as shown in Fig. 1. Each unit contains N blocks of height h · λd and width h · λd. Results are shown for h = 1/4 and l = 1/2. The intensity in the scattering order g can be expressed in terms of the Fourier transform Fg(bm) of the phase shift bm

of the individual blocks as: Ig = |Fg(bm)|2 (N2/ π 2) sin2(π/N). Using the angle of total internal reflection to distinguish between the intensity which is partially lost to absorption at the absorber/air interface and the one which is not, we calculate our predictor as the sum of the total internal reflected scattering orders. Figure 2 compares this predictor (dash-dotted green) with the absorption enhancement calculated by using the finite-difference time-domain (FDTD) method, implemented in the freely available software package MEEP[1] (red). A strong correlation between the predictor and the full numerical calculation can be seen. By using our predictor, the combinatorial space for the computationally more demanding and expensive simulations is drastically reduced. Already within the small design space shown in Fig. 2 (N=10, discrete binary profiles without variation of lateral block width and block height), we identify a structure with an absorption enhancement of 75%.Other possible predictors were considered by us as well. These include the “enhancement of the internal optical path-way”, which is included for comparison in Fig. 2 (dash-dotted blue). For these and numerous other binary profiles studied, the predictive power of Itot is considerably better than that of the alternative predictor.

J. M. Stockschläder, E. Runge

A simple efficiency predictor for metallic back-plane profiles of ultra-thin solar cells

Frank Weise | +49 3677 69-3423 | frank�weise@tu-ilmenau�de

[1] Weise, F�, et al�, Analysis and comparison of oxygen consumption of HepG2 cells in a monolayer and three-dimensional

high density cell culture by use of a matrigrid(R). Biotechnol Bioeng, 2013

[2] Fernekorn, U., et al., In vitro cultivation of biopsy derived primary hepatocytes leads to a more metabolic genotype in

perfused 3D scaffolds than static 3D cell culture� Rsc Advances, 2013

[3] Fernekorn, U., et al., Microbioreactor design for 3-D cell cultivation to create a pharmacological screening system.

Engineering in Life Sciences, 2011

IntroductionIn both the scientific community and research-based pharmaceutical industry, the concept of 3D cell culture has experienced considerable attention as it is capable of creating biochemical and oxygen gradients within such an in vitro generated micro tissue. The oxygen gradient in vitro is defined by the size of cellular aggregate which is deliberately supplied with predefined supplements. Mimicking the complex functions of in vivo physiology requires integrating different functional elements into the 3D concept. As the smallest functional unit within the liver, the liver lobule is characterized by high vascularization and a rich supply with both venous and arterial blood. Hepatocytes located close to the oxygen richer periportal area of the liver lobule have been reported to perform beta- oxidation processes, albumin and cholesterol biosynthesis. In the less oxygenated pericentral zone of the liver lobule, hepatocytes are predominantly involved in xenobiotic metabolism, lipogenesis, bile acid synthesis or heme synthesis. Primary hepatocytes are regarded as the gold standard for evaluating hepatic metabolism and toxicity of drugs and other xenobiotics in vitro. To theoretically evaluate our scaffold based 3D cell culture model, we compared the fluidic conditions within the scaffold to the conditions within the liver lobule.Results and DiscussionWe evaluated the impact of blood flow on oxygen concentration and distribution within the simulated liver lobule. In comparison, oxygen concentation and distribution in were calculated for perfusion of the lobule with cell culture medium. The blood perfused segment (Fig. 1 left) was characterized by a punctual maximum oxygen accumulation in the periportal areas. For the pericentral region, a massive depletion of oxygen was calculated. We then analyzed perfusion of the simulated liver lobule segment with cell culture medium. With this assumption, an extensive oxygen gradient extensively shifted to the pericentral area

was calculated. In contrast to the more diffusive oxygen transport in blood, conditions under medium perfusion are characterized by convective transport. Shear forces depend linearily on flow velocity and are therefore enhanced under medium perfusion. We hypothesize that adapting the flow rate in a perfused cultivation system (Fig. 1 right) can compensate for the physical limitations of oxygen solubilty in cell culture medium. The scaffold and the bioreactor system were recently described [1, 2]. Briefly, the MatriGrid® consists of 187 microcavities that were arranged as close packing of spheres by microthermoforming of a polycarbonate film [3]. Although the influence of high shear forces has been widely considered as a drawback for primary cell cultures, a flow rate of 25µl/min was proven applicable in our scaffold based 3D culture of biopsy derived primary hepatocytes [2]. In comparison to monolayer or static 3D cultures, we were able to observe higher CYP expression in a whole genome microarray, when the scaffold cultured primary hepatocytes were perfused. To extend and to verify our simulative results, future experiments need to utilize of oxygen sensitive probes within 3D cell cultures.

F. Weise, U.Fernekorn, J. Hampl, M. Klett, A. Schober

Converging in vivo and in vitro physiology: simulation of oxygen flow in the liver lobule

Fig. 1: Cells in liver lobule versus 3D culture

DESIGN & SIMULATION

Contact


142

Funding: FKZ B714 09 064, 03Z1M511, FKZ03ZIK062,

FKZ03ZIK465


Fig. 2: Force distance curves with applied different bias voltage

Fig. 1: Forces acting on sensor with applied bias voltage and thermal actuation


143

Contact

Funding: FP7/2007 - 2013. GA 318804 (SNM)

DESIGN & SIMULATION

1 Micro- and nanoelectronic Systems Group2 Nano Analytik GmbH, Ilmenau

Ivo W� Rangelow | +49 3677-69-3718 | ivo�rangelow@tu-ilmenau�de

[1] V. Mukundan and B. Pruitt, Microelectromechanical Systems, Journal of, vol. 18, no. 2, pp. 405–413, April 2009.

[2] J. Judy and N. Myung, Materials Research Society Symposium Proceedings, pp. 23–26, 2002.

[3] B� Lee, C� B� Prater, and W� P� King, Nanotechnology, vol� 23, no� 5, p� 055709, 2012�

[4] Y. Sarov, T. Ivanov, A. Frank, and I. Rangelow, Applied Physics A: Materials Science and Processing, vol. 102, pp. 61–68,

2011, 10�1007/s00339-010-6078-1�

[5] S. Manalis, S. Minne, and C. Quate, Applied Physics Letters, vol. 68, no. 6, pp. 871–873, 1996.

Selecting the proper and effective actuation technique for the micro-electro-mechanical systems (MEMS) is one of the main issues during design of the measurement system, because this determines its performance. Many MEMS actuation techniques are well established and used to solve different application problems. The common actuation techniques include: capacitive, electromagnetic, piezoelectric, and thermal, each one has its own advantages and disadvantages. Capacitive actuation uses electrostatic field between sensor and stationary electrode to pull the cantilever towards the electrode. This type of excitation is viable for cases when high force and high speed are needed and can also be used for specific biological measurements [1]. On the other hand, electromagnetic actuation uses magnetic-field forces to deflect the cantilever [2, 3]. This kind of excitation is used when high force and displacement, bi-directional actuation, contact less (remote) actuation, etc. are needed. Well known piezoelectric-effect can be used to cause strain in to the sensor by applying an electric field across a piezoelectric film. Advantages of piezoelectric excitation

are - very low power consumption, allowing high speed self-actuation and deflection feedback.For thermal actuators bi-layer structures are employed composed of a sandwich of thin-films with different thermal expansion coefficients [4]. This causes a deflection of the cantilever proportional to the applied thermal power [4, 5].Combining different actuation techniques can avoid some disadvantages and make the excitation more effective. For example, the combination of the electrostatic excitation with thermal actuation gives controllable modulation of the mechanical deflection of the sensor. This effect can be used for various applications, like Scanning Probe Lithography (SPL) in particular for writing quantum dots. Forces acting on the sensor are shown in figure 1 with applied bias voltage and thermal actuation. You can see that actuation force and electrostatic force are acting in opposite directions. With constant bias voltage and modulated thermal actuation, we are achieving so called amplification of the electrostatic force shown on figure 2 right, leading to an increase in the speed and amplitude of the sensor deflection. Force distance curves dependent on bias voltage are also shown in figure 2.

T. Angelov1, Tzv. Ivanov1, M. Holz2, I. W. Rangelow1

Distance and Actuation control at Scanning Probe Lithography (SPL)

Fig. 2: Typical equivalent circuit for a basic tuneable variable inductance varied through a change of forward transconductance

Fig. 1: Four basic tuneable reactance circuits with inductive (a and b) and capacitive (c and d) behaviour

DESIGN & SIMULATION

Contact


144

Funding: German Research Foundation (DFG) within the

project "Minaturised active radio frequency metamaterial

circuts" (HE3642/8-1)

RF and Microwave Research Group

Stefanie Kühn | +49 3677 69-1583 | stefanie�kuehn@tu-ilmenau�de

[1] I� B� Vendik and O� G� Vendik, Metamaterials and their application in microwaves: A review, Technical Physics, January

2013, Volume 58, Issue 1, pp 1-24�

[2] H. Schröder, Elektrische Nachrichtentechnik: Grundlagen, Theorie und Berechnung passiver Übertragungsnetzwerke. Bd.

1, 1975, Hüthig und Pflaum.

[3] S. Kühn, K. Blau, R. Stephan, and M.A. Hein, "Transistor-based Electrically Tuneable Reactance Circuits for Metamaterial

Transmission Lines", GeMiC 2014 and IEEE Xplore.

The growing demand for efficient use of RF and microwave hardware for a multitude of applications in communications and sensing leads towards reconfigurable systems, making tuneable elements substantial to circuit design. Reflecting their different operational principles such as mechanical, electric, or electronic tuning, the circuits differ in volume, mass, power consumption, linearity, power handling capability, as well as tuning range and speed. A novel electrical transistor-based approach to tuneable reactance circuits is investigated in the DFG-funded project “Miniaturised active radio frequency metamaterial circuits (MACRAME)”. The project is embedded into a strategic partnership with the Electrotechnical University St. Petersburg, Russia, enriching the research through their expertise in RF metamaterial circuit design. Given the rapid progress of high-frequency low-power transistor technologies, the reactance circuit concept is essential for a multitude of known and future applications based on lumped-element metamaterial circuits and devices built thereof [1].The concept of transistor-based reactances originates from vacuum reactance tubes [2] and, likewise to the forward trans con duc tance S in vacuum tube technologies, the tuneability of the present concept is based on the same

parameter in transistors. Opposed to existing transistor-based reactance tuning, not only will tuneable capacitances become accessible but also, more importantly, inductances that are hardly available otherwise due to the lack of integrated approaches. There are two possibilities to arrange the circuit elements, to achieve either inductive (Fig. 1 a, b) or capacitive (Fig. 1 c, d) behavior. As can be seen from the figure, all reactance circuits consist of the transistor as the key constituent and a passive feedback path, whereby the latter determines the type of reactance behavior at the output terminals of the linear reciprocal circuit.The effective reactance values L_eff ~ 1/S and C_eff ~S at the output ports, as depicted in the figures, are mainly controlled by the bias-dependent variation of S. To allow for a realistic simulation of the parameters influencing the transistor-based reactance, an equivalent circuit as shown in Fig. 2 can be devised. It is representative of an inductive circuit and is extended by input and output resistance, as well as forward transconductance. Based on the equivalent transistor model, different performance can be achieved in terms of high operating frequencies, high quality factors, and wide tuning ranges, therefore addressing a multitude of relevant circuit applications [3].

S. Kühn, K. Blau, R. Stephan, M.A. Hein

Electrically tuneable transistor-based inductance circuits for reconfigurable metamaterial devices


DESIGN & SIMULATION

145

Contact


Funding: European Union’s Seventh Framework Programme

FP7/2007- 2013, grant agreement no. 318804 (SNM), ZIM-

Project KF2114205NT2


[1] O� Sahin, G� Yaralioglu, R� Grow, S� F� Zappe, A� Atalar, C� Quate, and O� Solgaard, Sensors and Actuators A: Physical, vol�

114, no. 2-3, pp. 183–190, 2004.

[2] R. Pedrak, T. Ivanov, K. Ivanova, T. Gotszalk, N. Abedinov, I. W. Rangelow, K. Edinger, E. Tomerov, T. Schenkel, and P.

Hudek, Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, vol� 21, no� 6, p� 3102, 2003�

IntroductionAtomic Force Microscope (AFM) cantilevers have the ability to map topography and material properties simultaneously. The periodic impact of the tip onto the sample surface causes the material dependent excitation of higher harmonics in the Fourier spectrum. Combined with the cantilever dynamics, the harmonics in the vicinity of higher eigenmodes are less attenuated and can easily be detected by measurement devices. To improve the Signal-to-Noise Ratio (SNR), the cantilever eigenmodes can be matched with the harmonics that appear in integer multiples of the fundamental resonance used for scanning the topography. In the past, Sahin et al. [1] have created regular harmonic cantilevers during their fabrication process. However, they only matched a single eigenmode with a nearby harmonic at a time, and the yield was very low due to the fabrication process. In this work, harmonic cantilevers are created in a custom post-fabrication step, using cantilevers with integrated actuation and piezo-resistive sensing [2].FabricationThe harmonic active cantilevers are fabricated by removing mass at predefined locations and using a Focused Ion Beam

(FIB) tool. The shape and location of such mass removal is either determined beforehand through an FEM simulation or in-situ by monitoring the evolving cantilever signals at its resonances. In the simulation, the cut shape is swept in a parameterized fashion. Its proper size is determined based on the pre-cut and desired post-cut ratios. The result is shown in Figure 1, with Figure 1(a) being the digital mask as resulted of the FEM simulation. It is used to automatically create the holes in the cantilever by the FIB, as seen in the cantilever image of Figure 1(b) obtained by the scanning electron beam inside the FIB chamber. ResultFigure 2 indicates the measured resonances before and after the fabrication, as explained in the previous section. The original ratios of the second and third eigenmode to the first eigenmode are 6.219 and 16.885, respectively. The matched ratios after fabrication are 6.003 and 16.009. This allows for maximum SNR and contrast to different materials. Also, this technique can be used to lower the resonances of the higher eigenmodes such that it allows easier access with bandwidth limited actuation and sensor electronics.

A. Schuh, M. Hofer, T. Ivanov, I. W. Rangelow

Harmonic Active Atomic Force Microscope Cantilevers for Improved Material Contrast

Fig. 2: Resonance shift before (black curve) and after (red curve) the FIB modification. Arrows indicate the change

Fig. 1: (a) FEM based digital cantilever mask, (b) cantilever after FIB modification

Fig. 2: Thermal resistance of design A, B and C for different volume flow rates, the pressure drop for design A is shown

Fig. 1: Schematic layout of the LTCC device and cross-section through the LTCC device type C with freestanding vias in the channel

DESIGN & SIMULATION

Contact


146

Electronics Technology Group

Funding: iKersatec, funded by the Federal Ministry of

Economic Affairs and Energy

Tilo Welker | +49 3677 69-3385 | tilo�welker@tu-ilmenau�de

[1] T. Welker, J. Müller, “Design and fabrication of integrated fluidic channels for liquid cooling of a LTCC device“, IMAPS/

ACerS 10th International CICMT Conference and Exhibition, Osaka, Japan, 14-16 April 2014.

IntroductionBeside the possibilities low temperature co-fired ceramics (LTCC) offer for electric devices, they also enable the fabrication of micro fluidic elements like channels and embedded cavities. Hence, LTCC facilitate the realization of complex and integrated micro fluidic systems. Examples can be applied in many areas like micro fuel cells and reacting chambers. For many power applications it is necessary to have a short thermal path between a power semiconductor and a heat sink. One way to cope with the relatively poor thermal conductivity of LTCC is to bond the chip directly to the heat sink which requires a window in the substrate. In the presented investigation a coolant is pumped through a fluidic channel in the LTCC to cool down the device (Fig. 1). Thermal vias (dia. 260 μm, pitch 500 μm) are added in the ceramic and in the fluidic channel itself to optimize the thermal path between the chip and the fluidic channel.Test & ResultsThree designs are investigated which differ in the

configuration of the thermal vias. Design A is the reference without vias. Design B contains vias in the ceramic. Design C (Fig. 1) additionally contains vias in the fluidic channel. The design is fabricated using the DuPont 951 silver system in combination with high purity carbon tape to form the fluidic channels inside the LTCC. A thermal test chip (Delphi PST1-02, 2.5x2.5 mm²) is used to generate a thermal load and to measure the junction temperature. A syringe pump provides a constant flow (10–200 ml/min) of coolant through the device. The fluid inlet temperature is measured by an integrated platinum sensor. The thermal resistance is calculated from the temperature gradient between fluid and junction divided by the applied power. The measurements exhibit a nonlinear relation between the volume flow rate and the thermal resistance (Fig. 2). Design C shows the lowest thermal resistance of 3.1 K/W at 200 ml/min. In comparison to the reference in design A, the thermal resistance is reduced by about 60%.

T. Welker, J. Müller

Integrated fluidic channels for liquid cooling of a LTCC device


DESIGN & SIMULATION

147

Contact


Funding: EU FP7, “Nanoheat“, GA 318625

The self-actuated, micro-cantilevers with piezoresistive readout used in "Nanoheat"-project have a signal bandwidth of 10 kHz up to 10 MHz and signal amplitude of a few micro volts up to 1 mV (fig.1). The piezo resistor integrated on the micro-cantilever is configured in Wheatstone bridge with relatively high impedance and differential output. This requires the usage of a wideband low-noise amplifier, with high input resistance, placed very close to the sensor to prevent degradation of the signal-to-noise ratio.There are different techniques of designing a low noise preamplifier - cascade transistor circuit, single integrated circuit, combination between transistors and operational amplifiers, or a complex circuit built of several operational amplifiers.Usage of a transistor circuit leads to nonlinearity of the bandwidth and big thermal drift. Another thing that we also have in mind is the size of the preamplifier, the smallest size possible can not be achieved with a cascade transistor circuit.The single chip Op Amp concept is more meaningful and convenient. Our aim was to achieve very low noise figure

with reasonable gain and high stability without oscillation over the entire frequency range, but for such bandwidth, impedance matching is also crucial. With bandwidth over 6,5 MHz (fig.1) and high linearity, the designed device complies with all the above specifications.The noise figure of every electronic device consists of 5 different types of noise - shot noise, thermal noise, flicker noise, burst noise and avalanche noise. Flicker noise is also called 1/f noise because its influence is decreased with increasing the frequency. For our working frequency range, we can completely ignore the flicker noise. Burst noise is also a problem for low frequency signals, so it can be ignored too. The levels of shot noise and avalanche noise are very low, so they also can be overlooked. The noise factor is based mainly of thermal noise. A spectrum analyzer is used for Signal to Noise Ratio measurement (fig.2) which gives us the resolution of the module. Calculated value of the SNR for our bandwidth is -28,7dB. The other parameter, measured with a signal analyzer, which is also important for a low-noise amplifier, is total harmonic distortion which is only 0.2%.

Ivo W� Rangelow | +49 3677 69-3718 | ivo�rangelow@tu-ilmenau�de

[1] P. Horowitz (1994). The Art of Electronics - 2nd Edition.

[2] R. Mancini (2001). Op Amp for Everyone.

[3] W. Jung (2004). Op Amp Applications Handbook

[4] T. Grosch (2000). Small Signal Microwave Amplifier Design

I. Atanasov. T. Angelov, M. Hofer, M. Holz, Tzv. Ivanov,

I. W. Rangelow

Low-noise preamplifier for self-actuated cantilevers with piezoresistive readout

Fig. 2: Signal to Noise Ratio analysisFig. 1: Amplifier frequency response

Fig. 2: Numerical 3D FEM-model of LET using a quasi-static approach [3]

Fig. 1: Experimental setup with linear drive (1), 3D force sensor (2), permanent magnet (3) [1]

DESIGN & SIMULATION

Contact


148

Advanced Electromagnetics Group

Funding: DFG Research Training Group 1567, VIP 0437

03V0590, ZIM-KF 16KN020332

Hartmut Brauer | +49 0677 69-1189 | [email protected]

[1] H. Brauer, K. Porzig, J. Mengelkamp, M. Carlstedt, M. Ziolkowski, H. Töpfer, COMPEL, 33, 6 (2014).

[2] M� Carlstedt, K� Porzig, R� P� Uhlig, M� Zec, M� Ziolkowski, H� Brauer, International Journal of Applied Electromagnetics

and Mechanics, 45, 1 (2014)

[3] M. Zec, R. P. Uhlig, M. Ziolkowksi, H. Brauer, IEEE Transactions on Magnetics, 49, 8 (2014)

Nondestructive evaluation plays an important role during the manufacturing process of materials with a high demand of quality and reliability. The development of more advanced materials like, for example, carbon-fibre-reinforced plastics (CFRP) or glass laminate aluminium reinforced epoxy (GLARE) used in the framework of aeronautics poses new challenges in nondestructive testing. Lorentz force eddy current testing (LET) is a technique based on the induction of eddy currents caused by relative motion between a permanent magnet system and the object under test [1]. As a consequence, Lorentz forces arise which can be measured directly on the magnet system. In this way, LET is a contactless method to test and evaluate electrical conductive materials. The method is compared against the traditional eddy current testing technique (ECT). In ECT, the frequency dependent skin-depth results in a fast decay of the magnetic field inside the specimen. In contrast, the penetration depth in case of LET is higher when moderate testing velocities of v =1...2 m/s in case of aluminum are considered. Hence, LET is more suitable for the detection of defects buried deep inside the object under test [2].An experimental setup was developed and constructed

in the department of advanced electromagnetics at the Technische Universität Ilmenau. In this framework, the dynamic properties of the sensor system were investigated and inherently improved (Fig. 1).Moreover, numerical simulations were performed in order to predict Lorentz force profiles in general [3]. An optimization strategy was developed to improve the performance of the whole system by applying new innovative magnet systems based on the Halbach principle (Fig. 2). During the design process, the problem specificity of NDT scenarios was taken into account in order to provide most general optimization results while ensuring practical feasibility.The experimental and numerical Lorentz force profiles were studied in terms of their properties and informations content. As a consequence, they are in turn used to reconstruct the size, shape and location of the defect inside the specimen by solving the inverse problem.Ongoing and future research is devoted to the aforementioned topics as well as for the evaluation of CFRP and GLARE materials. Moreover, the capability to minimize a LET setup is being investigated in the framework of metal injection molding of small parts.

H. Brauer, M. Carlstedt, R. Schmidt, H. Töpfer, K. Weise,

M. Ziolkowski

Nondestructive Evaluation of Materials - Lorentz Force Eddy Current Testing


DESIGN & SIMULATION

149

Contact

Group for Theoretical Physics II/Computational Physics

Funding: DFG, Emmy-Noether-Nachwuchsgruppe

„Vielteilcheneffekte in mesoskopischen Systemen“ und

Forschergruppe FOR 760

Martina Hentschel | +49 3677 69-3612 | martina�hentschel@tu-ilmenau�de

[1] P. Stockschläder, J. Kreismann, M. Hentschel, Europhys. Lett. 107, 64001 (2014)

[2] M. Hentschel, H. Schomenus, Phys. Rev. E 65, 045603(R) (2002)

Ray optics can both explain natural phenomena, such as the rainbow, and serve as a simple yet versatile tool to describe microscale optical systems like microlasers and their far-field emission. However, just as geometric optics cannot explain the wave-originating supernumerary rainbow, corrections to ray optics are needed when reducing the cavity size to the order of several light wavelengths.These corrections, which violate Snell’s law and the principle of ray-path reversibility, are known as the Goos-Hänchen shift (GHS) - a lateral shift along the interface occuring upon total internal reflection - and the Fresnel filtering effect (FF) - an angular shift that corrects the direction of the reflected light. Both effects are schematically depicted in figure 1. They are well-known at planar interfaces, however, application of amended ray optics methods to devices with curved boundaries requires the knowledge of these semiclassical corrections at curved interfaces since the planar case formulae are not well-defined and generally yield incorrect far-field results. Here, we apply an approach that explicitly takes into account the boundary curvature [1].To analyze the beam shifts, we have performed, on the one hand, full electromagnetic simulations for the reflection of a light beam at a curved dielectric interface using the finite-difference time-domain (FDTD) method. Figure 2 shows the results of such a FDTD simulation for the reflection of a Gaussian beam at a microcavity interface for TE-polarization

at near-critical incidence. Both beam shift effects can be clearly seen: the lateral shift of GHS and the angular deflection of FF.On the other hand, we analytically described the reflection of a Gaussian beam at curved and planar interfaces using the respective Fresnel reflection coefficients [2] and obtained the beam shifts as expectation values of the electromagnetic field. In figures 3 and 4 the results of these calculations are shown for a beam of fixed width and polarization. It can be seen that both effects are highest near the critical angle, independent of the radius of curvature. However, with decreasing radius of curvature, i.e. for smaller cavities, FF increases whereas GHS decreases.An increasing number of simulations and experiments have found deviations from the naive ray-model and emphasize the importance of wave corrections in microcavities. We can show that corrections to the ray picture in the form of the beam shift effects GHS and FF are important even when the cavity size is not too small, especially when they are affected by curvature effects. Whereas the role of GHS decreases when decreasing the system size (i.e., the radius of curvature), FF becomes significantly more important at curved boundaries and should be taken into account when predicting the behavior and far-field properties of microoptics devices in the course of their ongoing miniaturization.

M. Hentschel, J. Kreismann, P. Stockschläder

Semiclassical Corrections to Ray Optics for Microoptics Devices with Curved Interfaces

Fig. 4: Curvature dependence of FF of a TE-polarized beam

Fig. 3: Curvature dependence of GHS of a TE-polarized beam

Fig. 2: TE-polarized Gaussian beam reflected at a convex interface

Fig. 1: Schematic picture of beam shifts at curved interfaces

Fig. 2: Fabricated microsystem (focus stacked photograph)Fig. 1: Essential system components of the miniaturized passive acceleration threshold detector

Contact


150

DEVICES

1 Micromechanical Systems Group

Hannes Mehner | +49 3677 69-1860 | hannes�mehner@tu-ilmenau�de

[1] X.-Q. Sun, S. Zhou, W.-N. Carr, Proc. Transducers 97 2 (1997).

[2] M. R. Whitley, M. Kranz, R. Kesmodel, S. J. Burgett, Proc. of the SPIE 5717 (2005).

[3] B. J. Hansen, C. J. Carron, B. D. Jensen, A. R. Hawkins, S. M. Schultz, Smart Mater. & Struct. 16 (2007).

[4] H. Mehner, C. Weise, S. Schwebke, S. Hampl, M. Hoffmann, Proc. MNE 2014 (2014).

Passive microsensors are especially of interest for applications where long time span (years) of operation are in between incidental but critical events that have to be measured. These systems need for data generation only the energy supplied by the event itself and they allow storing the detected event over an arbitrary long time period without the need of further energy supply. Microsystems for the passive detection of acceleration threshold violation by ratcheting have been published so far [1-3]. Applications for these systems are monitoring and indicating of maintenance necessity or crash recording [1, 2]. The reported systems are mainly characterized by one or two stable positions of a spring-coupled inertial mass [3] and most of the solutions are not resettable [1, 2]. Often the detection of multiple critical acceleration events or of an accumulated load is required.We present a novel passive mechanical microsystem for detecting and storing multiple lateral acceleration events [4]. The principle system design is given in Fig. 1.The central seismic mass (1) is coupled to the system frame (6) by guiding springs (2) so that it is virtually free to move in the sensitive direction. The corresponding ratcheting

components (3) are spring-coupled (4) to the system frame (6) and feature an electrostatic comb drive actuator (5) for reinitializing the system by releasing the coupling between (1) and (3). Inertial forces of external acceleration loads a(t) cause a movement of the seismic mass (1) relative to the components (3). The tooth shape inhibits the backward movement of the seismic mass after the acceleration event.An established standard SOI (silicon-on-insulator) technology was chosen for fabrication of the microsystem. The fabricated systems (Fig. 2) were investigated utilizing controlled impacts by dropping them from different heights with simultaneous recording of a 3-axis acceleration reference sensor. Various very low acceleration events showing amplitudes between 5•g and 30•g could be measured. The deviances between measurement and numerical results were in the range of ±1 “digits” as expectable for stepwise measuring systems. The system could be initialized using the integrated electrostatic actuator by applying a voltage of about 100 V which is in the expected range.The sensor can easily be extended for electrical read-out e.g. by RFID transponders or comparable systems that transmit the actual position of the seismic mass on request.

H. Mehner1, C. Weise, S. Schwebke, S. Hampl1, M.

Hoffmann1

A passive microsystem for detecting multiple acceleration events beyond a threshold


DEVICES

151

Contact

1 Micromechanical Systems Group2 Optical Engineering Group Funding: German Research Foundation (DFG) within the

priority program 1337 “Active micro-optics” – ADASCAN

(HO2284/1-2 und SI573/7-2)

Steffen Leopold | +49 3677 69-3372 | steffen�leopold@tu-ilmenau�de

[1] Steffen Leopold; Tobias Polster; Daniel Pätz et al. J. Micro/Nanolith. MEMS MOEMS. 12(2), 023012 (2013)

[2] Steffen Leopold; Daniel Pätz et al. In Proc. SPIE 8616, MOEMS and Miniaturized Systems XII, 861611 (2013).

[3] Steffen Leopold; Daniel Pätz et al. In Proc. of MikroSystemTechnik KONGRESS, Aachen, 2013.

[4] Daniel Pätz; Steffen Leopold et al., In Microlenses, Proc. OMN 2014, paper MOp3.4.

In optics, cylindrical lenses are used for imaging and projection systems, such as cinemascope®. Furthermore, two cylindrical lenses can be used for beam shaping. They are used for edge-emitting devices such as lasers and waveguides with different mode fields in the major axis. In optics, the properties of a system are usually tuned by changing the lens position. In contrast to this, in adaptive micro-optics the properties of each element can be tuned. For an adaptive microlens, the radius of curvature is changed. The most widespread approach uses polymer membranes that deflect due to a pressure load. For cylindrical lenses, only a few approaches are known.We introduce transparent aluminum nitride (AlN) membranes for tunable lenses. In contrast to polymers, AlN shows no creep [1]. For the membrane fabrication, AlN is deposited on a silicon substrate by sputtering from an aluminum target in an atmosphere of nitrogen and argon. AlN thin films show a characteristic nano-crystalline structure that inhibits the propagation of micro-cracks, and thus the fracture of the membrane. During reactive sputtering the mechanical stress of the thin film is controlled [1]. A backside lithography defines membrane shape. For the membrane release, deep reactive ion etching (DRIE) of silicon with almost perfect selectivity against AlN thin films is performed. This simple fabrication opens up the opportunity for circular, rectangular or even irregular membrane shapes.

Here, a “dogbone” shape is chosen (cf. Fig. 1). Compared to conventional long rectangular membranes, this layout has a smaller footprint with higher fraction of cylindrical properties, while its flexibility is maintained. The “dogbone” shape is a combination of square and two circular membranes. During optimization, the radius of the circles is tuned in order to get a cylindrical deflection. An optimum ratio of circle radius and edge length of the center part has been found [2].For deflection measurements, the membrane is assembled on a pressure chamber. A peristaltic pump combined with a pressure sensor are used for closed loop pressure control. The deflection is measured by white light interferometry. Fig. 2 shows a color-coded scan of a deflected membrane. A spherical deflection at the circular and the cylindrical deflection at the square part of the membrane are confirmed. Fig. 3 shows the cross-sectional data of the membrane deflection for the short and long axis of symmetry. A circular deflection is observed for the short axis of symmetry. In the perpendicular direction, a flat top of 1.5 mm width is measured. The maximum deviation of the measured profile from an ideal cylinder is 280 nm. We demonstrated cylindrical membrane-lenses made of AlN for beamshaping [3] and anamorphotic imaging [4]. Future work will focus on miniaturized actuation of the lens as well as optical systems integration.

S. Leopold1, D. Pätz2, S. Sinzinger2, M. Hoffmann1

Aluminum Nitride Membranes for Tunable Cylindrical Lenses

Fig. 2: Color-coded deflection measurement

Fig. 1: AlN “dogbone” membranes

Fig. 3: Cross-sectional data of membrane deflection along a) short and b) long axis of symmetry

Fig. 2: Performance of the supercapacitor based on Pt/MnO2 core/shell nanotube arrays

Fig. 1: High aspect-ratio Pt nanotube arrays within AAO template

DEVICES

Contact


152





[1] Y. Lei, W. P. Cai, G. Wilde, Progress in Materials Science 52, 465 (2007).

[2] M. H. Wu, L. Y. Wen, Y. Lei, S. Ostendorp, K. Chen, G. Wilde, Small 6, 695 (2010).

[3] L. Y. Wen, Z. Z. Shao, Y. G. Fang, K. M. Wong, Y. Lei, L. F. Bian, G. Wilde, Applied Physics Letters 97, 053106 (2010).

[4] F. Grote, L. Y. Wen, Y. Lei, Journal of Power Sources 256, 37 (2014).

[5] L. Y. Wen, Y. Mi, C. L.Wang, Y. G. Fang, F. Grote, H. P. Zhao, M. Zhou, Y. Lei, Small 10, 3162 (2014).

Due to the unique advantages of Pt, it plays an important role in fuel cells and microelectronics. Considering the fact that Pt is a very expensive metal, a major challenge nowadays is how to realize cost-effective utilization of Pt. To meet this challenge, an approximate fivefold reduction in Pt content is necessary at the present state of industrial development. Meanwhile, the trend of device miniaturization requires efficient techniques enabling Pt fabrication at nano-scale range so as to increase the overall surface-to-volume ratio and hence to reduce the Pt loading. Especially recently, great interests have been raised for synthesizing different kinds of Pt nanostructures, such as nano-dots, -wires by anodic alumina nano-porous template [1-3].Atomic layer deposition (ALD), which allows conformal and homogenous three-dimensional nano-fabrication with high structural controllability at atomic level [4], becomes a promising alternative approach for realizing continuous Pt nanostructures. During the initial period of the Pt ALD growth, dispersed Pt nanoparticles are usually appeared due to nucleation delay and inland growth. A real layer-by-layer atomic growth can only be achieved when the dispersed Pt nanoparticles coalesce into each other to finally form a continuous film. This requires a large number of ALD cycles and hence makes the ALD growth of continuous Pt nanostructures very costly. Meanwhile, due to the reaction limitation of Pt ALD in nanopores and the large molecular

mass of Pt precursors (MeCpPtMe3), the diffusion and transportation of Pt precursors in nanopores are very slow. This requires that the Pt precursor pulsing time should be sufficiently long enough to accomplish the precursor diffusion and reaction process within the nanopores.This issue is addressed in Ref.[2]: we developed a cost-effective ALD technique to synthesize Pt NT arrays within alumina nano-porous templates. Compared with conventional ALD growth of Pt, much fewer cycles and shorter precursor pulsing time are required, which originates from an appropriate N2 low filling step. To achieve similar Pt structures, about half ALD cycles and 10% Pt precursor pulsing time is needed using our N2 low filling step. Finally, the Pt nanotube array is explored as a current collector for supercapacitors based on core/shell Pt/MnO2 nanotubes. This nanotube electrode exhibits a high specific capacitance (810 F/g at 5 mV/s) and an excellent rate capability (68% capacitance retention from 2 A/g to 100 A/g). Negligible capacitance loss is observed after 8000 cycles of random charging-discharging from 2 A/g to 100 A/g.Our results demonstrated that the pre-defined Pt NT array can be utilized as a superior current collector for the next generation of supercapacitors and also opens up new opportunities for realizing other Pt-based nanostructured electrodes and catalysts.

LY. Wen, Y. Mi, Y. Lei

Cost-effective ALD synthesis of highly ordered Pt nanotubes for supercapacitor applications

Fig. 2: Breathing tube of a commercial system and connection to the new capnometry sensor concept

Fig. 1: Cuevette with optical freeforms, parabolic elements and infrared transmitting nanostructured silicon window


DEVICES

153

Contact

1 Micromechanical Systems Group2 Optical Engineering Group

Funding: Federal Ministry of Education and Research, FKZ

16SV5606 OxiVent

Christoph Weigel | +49 3677 69-3378 | christoph�weigel@tu-ilmenau�de

[1] Herzberg, G.: Einführung in die Molekülspektroskopie. Steinkopf-Verlag. Darmstadt. 1973

[2] Voigt, E�, Pelikan, J�: CO2-Messung in der Beatmung, Dräger Medizintechnik GmbH, (ISBN 3-926762-37-3)

Requirements for a capnometry sensorIn clinical monitoring the carbon dioxide concentration in real time is an important control parameter for patients with artificial respiration. The commonly used technique is infrared absorption at 4.3 microns wavelength [1]. The sensor system has to be optimized for the boundary conditions of toddlers, which have a high breathing rate by small volumes, and adults with high breathing volumes and low rates. To reduce the response time, smaller cuvette volumes are needed to reach a short changing time between the carbon-dioxide-free inspiration part and the expiration part with concentrations about 5 % [2]. Therefore, microsystems allow to reduce the dead volume and increase the dynamic by longer optical path length and sensitivity. A cuvette in the mainstream can increase the flow resistance and this can influence the respiration.System concept for a miniaturized passive systemA bypass sensor with induced passive flow caused by

Bernoulli Effect was designed. Furthermore, the above named disadvantage related to the flow resistance is overcome here. This provides flexibility when designing the optical system with nearly 25 mm optical path length but small cuvette volumes with 120 μl in the side stream. Thus, we used optical freeforms to achieve a collimated IR beam for the measuring and reference channel of the pyroelectric detectors. To decrease the costs of fabrication for an intended mass market, we use laser cut PMMA-forms. To divide the reusable sensor and emitter part from the low-cost and single-use enclosed cell, we make use of a nanostructured silicon window to reduce the reflections on the optical transitions and increase the transmission rate of the system. We achieved a simple but sensitive system with stable signals in a measuring range up to 10 % concentration with a superior measurement dynamic and with the opportunity of an easy integration into a commercial tubing system with a high dynamic.

C. Weigel1, A. Grewe2, M. Hoffmann1

Design and fabrication of a microoptical capnometry cuevette


Funding: German Ministry of Economy and Energy under

contract KF2731204WD3

Mario Kittler | +49 3677 69-1550 | mario�kittler@tu-ilmenau�de

[1] Effros RM, Swenson ER. Acid-base balance. In: Mason RJ, Broaddus CV, Martin TR, et al. Murray & Nadel's Textbook of

Respiratory Medicine� 5th ed� Philadelphia, PA: Saunders Elsevier; 2010

[2] Moncada, S.; Higgs, E. A. (1991): Endogenous nitric oxide: physiology, pathology and clinical relevance. In: Eur J Clin

Invest 21 (4), S. 361–374.

[3] Steinhoff, G.; Hermann, M.; Schaff, W. J.; Eastman, L. F.; Stutzmann, M.; Eickhoff, M. (2003): pH response of GaN

surfaces and its application for pH-sensitive field-effect transistors.

Precise as well as simultaneous measurement of a multitude of physiologically relevant parameters is important from a biomedical research standpoint, at times with an extremely limited sample volume. Nitric oxide (NO) is an example of a significant messenger molecule, particularly interesting due to its conflicting yet crucial roles involving cytotoxicity and as an intercellular messenger [1]. An additional parameter relevant to numerous biochemical processes is the activity of hydrogen ions, or the pH value, which is tightly regulated within living organisms. Slight deviation from the typical blood pH value of 7.35-7.45 [2] signifies a problem with acid-base homeostasis and can indicate respiratory or metabolic issues. Measurement of such analytes and the reduction of the aqueous sample volume is extremely interesting for pharmaceutical and clinical applications, e.g. the high-throughput screening of medicaments or the development of point-of-care systems. For these reasons, the development of a sensor system to measure pH and NO at physiologically relevant concentrations is introduced.The electrical behavior and sensitive properties of scaled-down AlGaN/GaN ion-selective field effect transistor based sensors were investigated using various designs, including a sensor line and an array (Fig 1). The open area between the drain and source contacts acts as the gate while the channel is formed by a two-dimensional electron gas within the heterostructure [3]. The channel current is influenced based upon the composition of the solution. Current-voltage characteristics for buffer solutions at pH 4 and 7 have been measured for the small-area sensors, varying the applied reference voltage Vref. Sensitivities were extracted from these curves for constant sensor current. Sensors with the smallest active area of 100 μm2 achieved a pH response near the theoretical Nernst limit of 59.1 mV/pH.Currently, the operating principle of a new generation of AlGaN/GaN-biosensors is under investigation to prove whether the desired NO sensitivity can be achieved. To accomplish this, sensors with a functionalization layer have

been fabricated utilizing various materials (e.g. metal oxides, graphene). In this case, the top functionalization layer comes in contact with the aqueous sample to be analyzed, acting as the biochemical interface of the biosensor. Dynamic measurement series were carried out monitoring NO concentration through changes in the sensor current at constant voltage versus time to demonstrate the response of a functionalized sensor structure. For different surface materials, a significant response of up to 2 µA/mM in sensor current can be observed.Further development will be directed at measuring pH and NO simultaneously using two different GaN-based small area sensors in a one-chip solution. In addition, an analysis system is underway to combine the measurement as well as the transport and exact positioning of sample volumes of less than 10 μl. This makes the simultaneous determination of multiple life signs parameters with minimum sample volumes possible, which not only opens the door for a new generation of analysis systems but also produces the opportunity for concurrent electrochemical measurement of activities for a multitude of cells.

M. Donahue, M. Kittler, S. Singh, M. Gebinoga, J. Hampl,

A. Schober

Electrochemical monitoring of multiple biological parameters with AlGaN/GaN based biosensors

Fig. 1: pH-sensitivity for various sensor designs. Inset: a) 4x4 sensor array, b) SEM and c) optical images of a single sensor

DEVICES

Contact


154


DEVICES

155

Contact

Funding: Federal Ministry of Education and Research under

contract 03IPT512Y

Process Measurement Technology Group

Christian Diethold | +49 3677 69-3188 | christian�diethold@tu-ilmenau�de

[1] M.-S. Kim et al., Atomic force microscope cantilever calibration device for cantified force metrology at micro- and nano-

scale regime: the nano force calibrator (NFC), Metrologia 43 (2006) 389-395

[2] M.-S. Kim et al., Report on the first international comparison of small force facilities: a pilot study at the micronewton

level, Metrologia 49 (2012) 70-81

[3] C. Diethold et al., Determination of force to displacement curves using a nanopositioning system based on

electromagnetic force compensated balances, Measurement (2014), doi:10.10

IntroductionThe calibration of force displacement curves (spring constants) of AFM cantilevers and the determination of force-signal curves (force sensitivity) of cantilever type micro force sensors is a known field of investigation in metrology. There are several measurement setups and measurement strategies as well as performed calibrations and international comparisons described in literature. Most systems have in common, that a force measurement system is combined with a displacement generation and measuring system [1,2]. The cantilever's spring constant is the quotient of acting force F on the cantilever and induced deflection z.Measurement setup and measurement resultsOur measurement system uses a force measurement system with combined displacement setting and measurement. The spring constant of a sample is determined by using an electromagnetic force compensated (short: EMFC) load cell. A modification of the control loop enables the possibility to set the displacement z of the weighing pan and measure the acting force F simultaneously [3].Additionally to this first measurement mode, it is also possible to set the displacement with a commercial piezoelectric nanostage and using the EMFC load cell for

force measurement only (measurement mode 2). This is related to the international state-of-the-art described by the international comparison [2]. The second mode can be used to verify the results of the first measurement mode.The EMFC load cell has a force resolution of 100 nN. We use a tactile stylus as load button for the cantilever as seen in fig. 1. The alignment of the cantilever is done with a xyz- motor driven stage and controlled with a long distance microscope camera as seen in fig. 2.The second measurement mode uses a piezoelectric nanostage for displacement setting with a determined repeatability of 1.9 nm (k=2).The displacement is measured traceable with a triple beam interferometer with 0.1 nm resolution.The spring constant of the investigated cantilever was determined to 49.18 N/m using measurement mode 1 and 49.04 N/m using measurement mode 2 with a very good repeatability of 0.02 %. The small discrepancy of the results is currently investigated.In the future, the investigations will focus on the measurement of different types of AFM cantilever and the effect of environmental influences.

C. Diethold, M.Kühnel, T. Fröhlich

Force displacement measurement device for the determination of AFM cantilever spring constants

Fig. 2: AFM-type cantilever in contact with load button, F - force, z - displacement

Fig. 1: Measurement setup with EMFC load cell, triple beam interferometer, piezoelectric nanostage and positioning system

Fig. 2: Deviation PV = 2,8µm RMS= 0,91μm

Fig. 1: (a) Presented Method, PV = 1,485 mm, RMS = 6,8µm. (b) Reference method “Raysence System in ZMN” PV = 1,487mm RMS = 12,4µm.

Fig. 3: Schematic set-up of the measuring concept by the use of a pyramid screen

DEVICES

Contact


156

Funding: Project “Kompetenzdreieck Optische Mikrosysteme-

KD OptiMi” (FKZ:16SV3700, FKZ: 16SV5473)

Optical Engineering Group

Mohamed Bichra | +49 3677 69-1806 | [email protected]

[1] O. Cakmakci, et al. Proc. Of SPIE, Vol 7060 (2008).

[2] G. S. Khan, et al. EOSMOC (2013).

[3] R. Kleindienst, et al. Proc. SPIE Vol. 8130, 8130-14 (2011).

[4] M� Bichra,et al� German Patent 10 2013 018 569�6�

IntroductionOptical instruments and devices nowadays require highly specific optical elements with enhanced performance [1,2]. However, the success of the fabrication of those elements techniques depends on the capability of precise metrology and on the feedback mechanisms for optimizing the manufacturing process [3]. We present a concept that allows high precision measurement of freeform [4].DescriptionThe sample is mounted on a precision positioning stage to realize scanning of the entire surface, Fig. (3). The upper half-space of the object is covered by a 3-dimensional screen. The screen contains one or more small apertures. Through these openings, a light pattern is directed onto the sample and reflected from the surface. A portion of the reflected light is scattered at the first surface of the screen. The remaining light portion is transmitted through the screen and will be visible on the second (outer) surface of the screen. This paper presents a possibility where the reflected light is visible on both screens. Because of the refraction at the screen-interface, the direction of the reflected beam in the measuring space is uniquely defined thus, from the incidence of the illuminating beam and the direction of the reflected

beam; it is possible to calculate the precise and absolute position of the reflection at the surface of the specimen.ExperimentThe setup contains a flat screen with a thickness of 35 mm and a mirror with 60 mm diameter. We use a helium neon laser with the wavelength 543.5 nm to scan the surface. An imaging system is used for simultaneously locating the two light spots on both surfaces. The recorded information is evaluated by Matlab and LabView programs. The validation of our measurement method is performed by a comparative measurement using a precise 3D measuring machine.Figures 1a and 1b illustrate the surface profile reconstruction firstly using our novel method and secondly using a commercial System (RaySense® by Photonic Metrology GmbH). Figure 2 shows the deviation between both methods.ConclusionBy using the presented method, a reflective or partially reflective freeform can be measured without a priori knowledge about its surface. Highly curved surfaces can be measured in an absolute way, and high accuracy is achieved. The measurement results were validated by a comparison with measurements from commercial systems.

M. Bichra, S. Sinzinger

Method and apparatus for detecting the surface shape of reflective freeform optics

Fig. 2: Design concept and 1st modular form. Source: IMMS

Fig. 1: Dynamic characterization setup. Source: IMMS

Fig. 3: SEM image of a 5x5 mm2 oscillator with details (left), transmitted light images of 2nd generation structure after DRIE


DEVICES

157

Contact

Funding: Thuringian Ministry of Economics, Labor and

Technology (TMWAT) and the European Social Fund (ESF),

Grant No� 2011 FGR 0121

1 Micromechanical Systems Group2 IMMS GmbH, Ilmenau

Stefan Hampl | +49 3677 69-1860 | stefan�hampl@tu-ilmenau�de

[1] S. Hampl, B. Leistritz, B.Saft, M. Hoffmann and E. Hennig, “Micromechanical, vertical comb-drive-structures for

the construction of an electrocstatic energy harvester”, Proc. of 7. GMM-Workshop on energy self-sufficient sensors,

Magdeburg, Feb. 24th-25th 2014, p. 14-19.

[2] B. Saft, E. Schäfer, A. Jäger, S. Hampl, B. Leistritz, E. Hennig, “A System Architecture for an Integrated Electrostatic MEMS

Energy Harvesting Module”, Proc� of 14� GMM/ITG-Conference ANALOG 2014, Hannover, 2014�

IntroductionAs innovative supply option for self-powered nodes of multimodal sensor networks even microscale vibration energy harvesters increasingly become a viable option to convert small amounts of ambient kinetic energy. In the research project GreenSense a novel realization of a low-frequent electrostatic energy harvester as out-of-plane overlap type is demonstrated by concept, microfabrication and experimental characterization of single-layered test structures, [1].Working principle and microfabricationWhile the device oscillates perpendicular to the wafer plane, the capacitance changes with the overlap area of the interdigitated electrodes, (Fig. 2). This design approach particularly provides high areal densities of capacitance (Cmax in the 500 pF range for chip area ≤15x15 mm2) and for vertical deflections up to 100 µm high capacitance ratios ac=Cmax/ Cmin between the neutral and turning position. Together with a high-voltage/ low-power CMOS frontend IC and a lithium microbattery, the intended harvester module will operate with voltages up to 40 V for a continuous power output in the double-digit μW range, [2]. As highly z-compliant and fatigue-proof oscillator guidance, a combination of 90° rotated double yoke springs of monocrystalline silicon provides the assumed omnidirectional transverse stiffness in the lateral plane (clat>>100*cz). The monolithical

microfabrication bases on double-sided DRIE etching of 100 mm SOI substrates, [1]. As first technological main point the developed multilayer spray coating and dry etching regime ensures both, the masking of the incused spings and the pattern resolution for the front-side DRIE trench etching with high aspect ratios (up to 33 for 100 μm electrode height). Secondly the harvester design preserves the heavily stressed BOX-layer as etch barrier for back-side release, (Fig. 3).First experimental resultsDynamic measurements were performed on a laboratory setup of a shaker, coaxial accelerometer and a vibrometer. According to spring thickness, so far in air frequencies of 1st resonance of 90 - 260 Hz, vertical deflection amplitudes in the higher two-digit μm range and Q factors in the range of 10 till 30 were achieved, (Fig. 1). A slight resonance shift indicates progressive springs. Concept inherent gravitational sagging is significantly reduced for 2nd generation samples of higher frequency (z0≈25 µm/≤6 µm for f0=100 Hz/≥200 Hz). For quasistatic capacitance measurements the oscillator was deflected by a prober chuck needle. Considering design-related parasitics, values of the working capacity correspond well with simulation results, showing ratios up to ac≈4. The presented systems are a proof of concept, but the harvesters performance can be enhanced by technological ways (quality/ aspect ratio of electrode trenches) and design (multilayer comb-drives with stacked stator electrodes), [2].

S. Hampl1, B. Leistritz2, B. Saft2, E. Hennig2, M. Hoffmann1

Micromechanical, vertical comb-drive-structures for a novel electrostatic energy harvester

Funding: Masdar Institute, A. S. by DAAD., FP7/2007- 2013,

GA 318804 (SNM)

1 Massachusetts Institute of Technology, MECHE2 IUT, MNES


[1] N. F. Martinez, S. Patil, J. R. Lozano, and R. Garcia, Applied Physics Letters, 89(15):153115, 2006.

[2] John Melcher, Carolina Carrasco, Xin Xu, José L. Carrascosa, Julio Gómez-Herrero, José de Pablo, Pedro, and Arvind

Raman. Proceedings of the National Academy of Sciences of the United States of America, 106(33):13655–13660, 2009.

[3] Tzv. Ivanov, T. Gotszalk, T. Sulzbach, and I. W. Rangelow. Ultramicroscopy, 97(1-4):377–384, 2003.

IntroductionIn multifrequency Atomic Force Microscopy (AFM), signals of higher harmonics and actuated higher eigenmodes are captured to retrieve information about the material of the sample under investigation. Here, the fundamental resonance is utilized to obtain the topography of the sample and to keep a set distance of the cantilever tip to the surface. For example in bimodal AFM, the first two flexural eigenmodes are actuated, where the second eigenmode’s phase shift is one order of magnitude more sensitive to material compositions than the first eigenmode [1]. In contrast, active Q control of the fundamental eigenmode has been reported to also enhance its phase’s sensitivity to material properties [2]. In this work, multifrequency methods are combined with active Q control to modify the dynamics of fundamental and higher eigenmode separately and independent of each other. The cantilevers utilized in this investigation are active, as they are self-actuated (bimorph) with piezo-resistive displacement proportional sensors [3].CompensatorThe compensator, based on a prediction estimator and controller, allows the arbitrary modification of the cantilever’s system poles. It means that natural frequency, Q factor or a combination of both can be set for every eigenmode. Each eigenmode of the cantilever can be satisfactorily described by a second order dynamic system. Hence, the Kalman estimator is needed to supply each vibrating eigenmode’s unmeasured velocity proportional signal. Following, a cantilever model describing two or more eigenmodes can be created by a superposition of each individual eigenmode’s model. The compensator is implemented in a digital form into two different Xilinx FPGA based platforms for performance comparison. The prediction form of the estimator, combined with a state-machine implementation, allows maximum loop rate and minimal computational delay times. In addition, floating point representation minimizes the risk of numerical saturation. The implementation in a

Virtex-5 LX110 has a maximum compensator feedback loop rate of 5.56 MHz. This is about twice as fast as in the case of a Spartan-3A DSP with a loop rate of 2.77 MHz. Hence, higher eigenmodes up to the Megahertz range can be modified by the compensator.ResultFigure 1 shows the independently modified first two flexural resonances of an active cantilever. The color of each frequency sweep refers to a specific combination of Q factors of the first eigenmode (Q1) and second eigenmode (Q2). The different Q factors can be noticed in the phase signal as well. A promising combination is a low Q1 and high Q2. As the first eigenmode is used for the topography feedback imaging, the low Q1 results in a high bandwidth of that resonance and hence fast scanning ability. In addition, the higher forces exerted on the sample enable the improved sensitivity in the higher eigenmode that can be further enhanced with a high Q2. As a result, a flexible imaging system is introduced that allows flexible tuning of different tasks that are split onto two or more cantilever eigenmodes.

A. Schuh1,2, I. S. Bozchalooi1, K. Youcef-Toumi1,

I. W. Rangelow2

Multi-Eigenmode Compensator for Multifrequency Atomic Force Microscopy

Fig. 1: The first two flexural eigenmodes under Q control. As indicated, each eigenmode can be assigned with individual Q factors

DEVICES

Contact


158


DEVICES

159

Contact


Funding: Federal Ministry of Education and Research (BMBF)

16SV3853

Stefan Hampl | +49 3677 69-1860 | stefan�hampl@tu-ilmenau�de

[1] S. Hampl, M. Hoffmann, "Piezoelektrischer AlN-Bimorph als resonanter Mikroaktor", Proc. of 11. Chemnitzer Fachtagung

Mikrosystemtechnik, Chemnitz, 23�-24� Okt� 2012, p� 102-106�

[2] S. Hampl, M. Hoffmann, "Piezoelektrische AlN-Bimorphe als niederfrequent-resonante Mikroaktoren mit großem

Stellweg", Proc. of MikroSystemTechnik KONGRESS, Aachen, 2013, 14.-16. Okt. 2013.

IntroductionFor applications of energy-efficient microscale actuation, demanding high-amplitude travels normal to the substrate plane resonant systems are in focus. In contrast to electrostatic concepts which require high driving voltages even in resonance, bending beam transducers of piezoelectric thin films (d31) show high electric field strength and thus large displacements for a low-voltage excitation. Furthermore, piezoelectric principles distinguish themselves by a linear behavior under very low power consumption. Irrespective of lower electromechanical coupling, nanocrystalline thin films of aluminum nitride (AlN) with strong c-phase orientation offer a few advantageous characterisitics such as lead-free piezoelectric material of comparatively low permittivity. They can be deposited by low-temperature reactive magnetron sputtering while being CMOS-compatible, [1]. AlN layers of a few 100 nm thickness have a dielectric strength up to tens of volts and a remarkable mechanical stability.Research ObjectiveBased on analytic descriptions and FEA of the static, modal and harmonic behaviour, a transducer concept of microcantilevers using a symmetric AlN/ electrode stack in parallel bimorph configuration is demonstrated, [2]. Waiving of a passive supporting layer for a given thickness increases the piezoactive volume. A process flow for stack deposition (using molybdenum as electrode and nucleation layer), patterning

and dry chemical release was developed. Bimorph beams with lengths ranging from 200-1200 μm and thicknesses of only 0.7-1.5 μm (including electrodes) were fabricated and experimentally investigated, [2](Fig. 1). At just 1 mm² of footprint, their resonant oscillation in the range of frequencies below 100 Hz requires a large seismic mass attached to the clamped, highly z-compliant bending spring. Bulk silicon patterned using backside DRIE was used for additional tip mass.In air, the released transducers can be operated even from actuation amplitudes below 5 V, showing absolute tip deflections of tens of µm (shown for a trapezoidal beam of 0.9 mm length in Fig. 2). In unimorph operation (one piezoactive layer grounded), the contribution of each AlN-layer can be rated separately showing slightly higher values for the lower layer due to its better crystalline orientation (Fig. 3, distance x=300 μm). For the prevention of higher eigenmode tumbling, several equally shaped beams are mechanically parallelized, (Fig. 1). Static tip deflection by intrinsic layer stress is shown to be significantly reduced by controlled deposition.Bimorph benders show potential as a sensoric readout of the oscillator's deflection and phase in relation to the excitation, if the crosstalk of the excitation signal can be minimized by a suitable design of electrodes. The direct integration of functional elements holds various possibilities for the utilization of the transducers.

S. Hampl, M. Hoffmann

Piezoelectric AlN-bimorph-benders as low-frequent microactuators

Fig. 2: Deflection amplitude for unimorph/ bimorph operation

Fig. 1: Frequency sweeps (rising) at 1st resonant frequency

Fig. 3: SEM image of nanocrystalline AlN (left), microscopic and vibrometric bimorph images of 1st eigenmode (Project AINTEN)

Fig. 4: Transfer characteristic L=10μm, W=500μm

Fig. 3: Output characteristic L=10μm, W=500μm

Fig. 2: Design of a single transistor

Fig. 1: Chip layout of investigated thin film transistors

DEVICES

Contact


160

Funding: Deutsche Forschungsgemeinschaft (DFG) Project

No� SCHE 645/7-1

Susanne Scheinert | +49 3677 693714 | susanne�scheinert@tu-ilmenau�de

[1] Halik, M., H. Klauk, U. Zschieschang, G. Schmid, Ch. Dehm, M. Schütz, S. Maisch, F. Effenberger, M. Brunnnauer und

F. Stellacci: Low-voltage organic transistors with an amorphous molecular gate dielectric. Letters to Nature, 431:963–966,

2004�

Research ObjectiveThe goal of the project is the development of polymer semiconductor based transistors with low operating voltage, convenient for the realisation of inexpensive electronics. ExperimentalThe chip layout is shown in figure 1. It contains transistors with different channel lengths from 2 to 100μm. The width is varied between 500 and 1000µm. The thin film transistors are realised in a bottom gate structure on a glass substrate, with aluminium gate contacts. The gate oxide was formed by oxidation of the aluminium by oxygen plasma and an additional self assembled monolayer with a typical oxide area capacitance around 1μFcm-2. This insulator system is a promising candidate for organic electronics and known for good interface properties from the literature [1]. Source and drain electrodes are wet chemical etched with the aid of photolithography. The semiconductor layer was made by spincoating and is preliminary covering the complete chip. To structure and passivate the active semiconductor material, the complete chip was covered with a 100nm photosensitive benzo cyclobutene (BCB) layer. The active area and the source/drain areas are illuminated by UV

light trough a mask to crosslink the BCB in these areas. Unilluminated parts of the BCB layer are removed by a liquid developer. Finally, the semiconducting polymer, outside the BCB covered areas, was removed by argon plasma resulting in bottom contact transistor structure like in fig. 2. The measured output characteristic for a transistor with a channel length of 10µm is shown in fig. 3. The differences between the solid and dashed lines indicate some hysteresis effects, depending on the gate voltage step direction. Fig. 4 depicts the transfer characteristic of the same transistor. From the trans con ductance in the linear regime, the hole mobility in the semiconductor was calculated to 0.01cm2V-

1s-1. OutlookFor the future, the transfer of the technology from glass to foil substrate is scheduled. We will also work on increasing the maximum operating voltage to 3V. Furthermore, we want to use nanoimprint lithography to apply the semiconductor structure in order to avoid the argon plasma etching step. To investigate the device performance and identify limiting effects, such as contact properties and traps states, we use two dimensional numerical simulations.

I. Hörselmann, S. Scheinert

Realization of low voltage transistors with polymer semiconductor

Solid State Electronics Group

Fig. 2: Current gain subject to the drain-source voltage and the gate-source voltage

Fig. 1: Curvature dependence of T-shape TTJ devices as a function of the horizontal branch width


DEVICES

161

Contact

1 Nanotechnology Group2 Group of Nanostructured Materials, Universität Halle3 Solid State Electronics Group

Funding: DFG Pe 627/11-1


[1] R. Göckeritz, J. Pezoldt, F. Schwierz, Appl. Phys. Lett. 99, 173111 (2011)

[2] A. Jacobson, I. Shorubalko, L. Maag, U. Sennhauser, K. Ensslin, Appl. Phys. Lett. 97, 032110 (2010)

[3] B. Händel, B. Hähnlein, G. Göckeritz, F. Schwierz, J. Pezoldt, Appl. Surf. Sci. 291, 87 (2014)

Graphene is a fascinating new material, whose properties are very promising for electronic applications. Especially the mobility, the electrostatic control of the carrier type and their concentration and the aggressive scalability of graphene devices offer advantages for deep scaled and high frequency devices. Nevertheless, the unique band structure of large area graphene with no band gap and linear dispersion around the Dirac point calls for new concepts to explore graphene’s unique capabilities in electronics. A promising concept in this respect are the three-terminal junction devices (TTJ) [1, 2]. These T- or Y-shaped devices of sub-micrometer dimensions capitalize on certain characteristics of the nonlinear response regime of charge carrier transport appearing in two dimensional charge carrier gases confined laterally in channels. In these devices geometrically or electrically controlled charge transport as well as a rectification can be used for information processing and was demonstrated on III-V heterostructures. Recently, the rectification effect was also demonstrated on graphene [1, 2]. In contrast to III-V heterostructures where only one carrier type is available, the

graphene TTJ allows the electrical tuning of the rectification effect from negative to positive rectification as a function of the carrier type in the device, negative rectification in case of electron conduction and positive rectification if the holes are responsible for the charge transport [2]. The graphene was grown on semi-insulating silicon carbide. The all carbon devices were fabricated using electron beam lithography. T- and Y-shape devices were fabricated. The channel width was between 8 and 160 nm. The rectification effect was observed independent of the shape of the junction. The rectification properties of the device can be tuned by changing the geometrical device design [3]. This is shown in Fig. 1. Beside the rectification, these devices exhibit a switching behaviour. By measuring the output conductance and the transconductance, it was possible to demonstrate that the efficiency and gain was dependent on the branch width of the device. This would offer tunable properties [3]. An example of the current gain as a function of the drain-source and gate-source voltage is given in Fig. 2.

B. Händel1, R. Hähnlein1, R. Göckeritz2, F. Schwierz3,

J. Pezoldt1

Rectification and amplification in three terminal graphene junctions

Fig. 2: ATLAS simulated output as a function of charge density

Fig. 1: REM image of a Three-Terminal Junction device

Fig. 3: Transition for negative to positive rectification behaviour in TTJ devices with bar width of 58 nm, 550 nm and 690 nm

DEVICES

Contact


162

1 Nanotechnology Group2 Solid State Electronics Group


[1] Ch� Förster, et al�, Mater� Sci� Forum 483-485, 201-204, 2005�

[2] L� Hiller and J� Pezoldt, IEEE Trans� Electron Devices, Bd� 60, Nr� 10, pp� 3047-3052, 2013�

[3] H� Q� Xu, Appl� Phys� Lett�, Bd� 78, Nr� 14, p� 2064, 2001�

[4] Z� Lin et al�, Electron� Lett�, Bd� 39, Nr� 19, p� 1412, 2003�

[5] B� Delley and E� F� Steigmeier, Appl� Phys� Lett�, Bd� 67, Nr� 16, p� 2370, 1995�

We present the realization of Three-Terminal Junction (TTJ) devices based on AlGaN/GaN heterostructures grown on silicon substrates using a SiC transition layer [1]. The growth of AlGaN/GaN heterostructures on Si (111) was performed using metalorganic chemical vapour deposition (MOCVD). Electron Beam Lithography (EBL) was used to structure the T-shaped active region of the TTJ devices. As masking material a CoPMMA/PMMA system of about 400 nm thickness was the resist of choice for the structures above widths in the nanometer scale. For the active part a 100 nm thick PMMA resist was used solely with a higher acceleration voltage and smaller aperture for the EBL. The etching process was done in an Inductively Couples Plasma (ICP) chlorine plasma to form the mesas for device isolation. The contacts to the 2DEG were realised with a Ti/Al/Ti/Au system. They were annealed and thus alloyed by Rapid Thermal Processing (RTP) in an argon-hydrogen gas mixture at atmospheric pressure at 825°C. The density of the two dimensional electron gas was 6.7×1012 cm-2 measured with the van der Pauw Hall measurement. Electron mobility was

found to be 1520 Vs/cm2 [2].Three-Terminal Junction devices consist of three connected nano junctions. In push-pull-measurement configuration the device is known to show rectification behaviour. This common measurent method is set up to provide a symmetrical input, where the voltage at the right branch (VR = +V0) is the opposite polarity as that in the left branch (VL = -V0) and the output is the central-contact-voltage (VC) (Fig.1). VC is reported to be negative for any input V0 [3]. As shown in [2], a geometrical dependence allows the transition to positive rectification behaviour. The completely negative VC turns to positive values with wider branches between the contacts L and R (Fig.3). Using twodimensional ATLAS simulations, it could be shown that the positve rectification effect can be explained by a variation of the charge density along the branch (Fig. 2). This variation might be created by depletion effects near the contacts [4] or by 2DEG density enhancements due to band gap widening because of narrowing the AlGaN/GaN material [5].

L. Hiller1, R. Granzner2, F. Schwierz2, J. Pezoldt1

Rectification characteristics of AlGaN/GaN-based Three-Terminal Junction devices


DEVICES

163

Contact

1 Micromechanical Systems Group2 μHybrid Electronic GmbH, Hermsdorf3 Siegert TFT GmbH, Hermsdorf

Funding: BMBF, contract 16SV5360 - NaMiFlu

Lutz Müller | +49 3677 69-1860 | l�mueller@tu-ilmenau�de

[1] W. Lang, K. Kuhl, and H. Sandmaier, Sensors and Actuators A, 34 (1992) 243-248

[2] S. Leopold, L. Müller, C. Kremin, and M. Hoffmann, J. Micromech. Microeng. 23 (2013) 074001 (6pp)

[3] L. Müller, I. Käpplinger, S. Biermann, W. Brode, and M. Hoffmann, J. Micromech. Microeng. 24 (2014) 035014 (9pp)

[4] T. Castro, R. Reifenberger, E. Choi, and R. P. Andres, Physical Review B, 42, 13 (1990) 8548-8556

Broadband IR emitters are key elements for IR-spectroscopic sensors. Thermal emitters such as silicon based micro-hotplates coated with highly emissive noble metal nanostructures (soot) [1] are well-known and reliable solutions. Their major disadvantages are the limited temperature range caused by relocation effects in metal nanostructures far below the melting point and the deposition process of the soot, either by high-pressure evaporation (causing grime on all surfaces) or by electroplating. Due to the relocation effects, even Pt soot can only be operated up to less than 500°C permanently. For this reason, a new technology was developed that overcomes these disadvantages: An optically dense but well-oriented arrangement of nanostructures is achieved by (common low-pressure) evaporation of noble metals on a 3D silicon template and an additional coating suppresses relocation effects.At first, a 3D silicon template is fabricated on a silicon micro-hotplate by using a modified deep reactive ion etching (DRIE) process for Si grass generation controlled by optical emission spectroscopy [2]. On this 3D template an evaporation of Pt at low pressure is performed. Due to a local “glancing angle” deposition on the 3D template, single nanocrystals (Fig. 1) grow on the scalloping whereas a dense thin film of noble metal is deposited anywhere else and, thus, the chamber is kept clean. In contrast to usual glancing angle deposition

for absorbing layers, no tilted or turning substrate holder is required here, and the needles are less dense but vertically stacked. As a result of combined silicon grass etching and noble metal deposition, a highly absorbing / emitting coating is achieved on a micro-hotplate superior in performance to other soot-based emitters [3].As with all kinds of metallic structures within the nanometer-scale, this structure is not suitable for higher temperatures [4]. The ordered Pt needles transform by relocation effects far below the melting point into larger, faceted spheres. It turned out that a thin silica layer by plasma CVD can efficiently suppress relocation effects, especially on our highly ordered nanostructures (as seen in Fig. 1). A thin silica layer encloses the oriented nanostructures almost conformally due to their stacked 3D orientation (Fig. 2).The presented fabrication process is fully compatible with thin film processing and does not require dedicated equipment. This type of emitter is intended for an IR spectroscopic sensor system that allows online monitoring of oil deterioration in high-pressure systems, but it can just as well be used in a wide range of IR spectroscopic applications. As compared to the basic micro-hotplate emitter used here, the IR emission was increased by a factor of 2.5, and the Fresnel interference pattern caused by the silicon-air interfaces in thin micro-hotplates is completely suppressed (Fig. 3).

L. Müller1, M. Hoffmann1, S. Biermann2, I. Käpplinger3,

W. Brode3,

Silicon-Platinum nanostructures for highly emissive surfaces in hotplate emitters

Fig. 2: SEM image of SiO2 coated Si-Pt nanostructures

Fig. 1: SEM image of emitting silicon-platinum nanostructures

Fig. 3: Measured spectral emission of a conventional silicon hotplate without nanostructures and a modified hotplate with nanostructures

Fig. 4: Electrical circuit of the sensor

Fig. 3: Design of the temperature and humidity sensor

Fig. 2: Lines and spaces with a pitch of 20 um

Fig. 1: Principle of the planarization technology

DEVICES

Contact


164

1 Electronics Technology Group2 Group for Inorganic-Nonmetallic Materials3 Micromechanical Systems Group

Boris Goj | +49 3677 69-3658 | [email protected]

[1] Boris Goj et al.: Thin-film Capable Ceramics For Humidity and Temperature Sensing Applications. In: Proc. 58th

International Scientific Colloquium, Ilmenau, 2014

[2] George W� Scherer: Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing� Orlando: Academic Press Inc, 1989

[3] DuPont AG.: Dupont GreenTape: Design and Layout Guidelines. Online: www.dupont.com (14.10.2014)

[4] Boris Goj et al.:Temperatur- und Feuchtsensor basierend auf planarisierten LTCC-Oberflächen. VDE-Verlag: GMM-

Fachbericht 81, 2014. ISBN 978-3-8007-3632-4

IntroductionThe focus of the presented work was the generation of thin-film capable substrates made of Low Temperature Co-fired Ceramic (LTCC) without expensive and time consuming grinding or polishing processes. Two planarization methods were investigated during the project SolCer [1]. The first is based on a thin sol-gel layer which is dip coated [2]. The second planarization method utilizes a screen printed glass paste to smoothen the surface of the substrate [3]. The emerging advantages using thin-film capable LTCC instead of silicon are the availability of solderable thick film materials, the high isotropic young’s modulus and the possible integration of buried structures (e. g. conductors, vias, heaters). The benefit of thin-film capable ceramics was demonstrated utilizing an innovative temperature and humidity sensor.Planarization methodGlass layers on the top of the LTCC substrate smooth the surface locally (Fig. 1). On this planar area thin-films like gold can be deposited and structured with small feature sizes and good electric properties. A dip coated sol-gel layer is suitable for initial smooth surfaces without structured features [2]. For three-dimensional substrates the glass paste DP9615 is suitable because screen printing can be done on structured surfaces [3]. The electrical contact to the LTCC layer below is realized through an opening which can be etched into the

glass layer or directly structured by screen printing. First planarization experiments demonstrated that the sol-gel layer and the screen printed glass paste decrease the roughness of the substrate considerably. Thus, the lithography resolution and structure dimensions were decreased down to 5 micrometers. Additionally, the specific resistance of a 100 nm sputtered gold film could be decreased down to 4.1 x 10 -8 Ω/m. Therewith, our thin-film capable LTCC substrates enable sensor structures like fine meanders or interdigital electrodes (Fig. 2) which are typically used on silicon based micromechanical sensors.Design of the sensorThe temperature and humidity sensor comprises two interdigital resistors made of the hydrogel polyvinylalcohol (PVA) and four meandred resistors made of gold and chrome (Fig. 3). The measurement principle of the sensor is based on a DC and AC bridge circuit (Fig. 4). If the temperature changes, the DC bridge is detuned because of the different thermal coefficient of resistance of gold and chrome. If the relative humidity of the surrounding air increases, the AC bridge is detuned because of the increasing water absorption of the PVA film. The DC bridge is not influenced by a change of relative humidity, because the PVA resistance is much higher at low frequencies. Thus, the humidity and temperature are measured utilizing the amplitude and the offset of the output voltage [4].

B. Goj1, H. Bartsch1, U. Brokmann2, S. Hanitsch3, E. Rädlein2,

M. Hoffmann3, J. Müller1

Temperature and humidity sensor based on thin-film capable ceramics


DEVICES

165

Contact




[1] F. Grote, R. S. Kühnel, A. Balducci, Y. Lei, Applied Physics Letters 104, 053904 (2014).

[2] L. Wen, Y. Mi, C. L. Wang, Y. Fang, F. Grote, H. P. Zhao, M. Zhou, Y. Lei, Small 10, 3162 (2014).

[3] R. Vellacheri, A. Al-Haddad, H. Zhao, W. X. Wang, C. L. Wang, Y. Lei, Nano Energy 8, 231 (2014).

[4] F. Grote, L. Wen, Y. Lei, Journal of Power Sources 256, 37 (2014).

[5] F. Grote, Y. Lei, Nano Energy, accepted and in press (2014).

Energy storage is one of the key challenges of mankind in this century in order to meet the requirement of an increasing intermittent energy supply. Among others, supercapacitors play a crucial role and are discussed as a desirable solution to address the emerging challenges. In the past decade various approaches have been made to increase the performance of supercapacitors. In particular, new nanostructured electrodes of pseudocapacitive materials (e.g., metal oxides [1,2]) and graphene [3] have been introduced. So far, two major challenges exist: (i) highly promising supercapacitor materials such as MnO2 suffer from high internal resistance [1]; (ii) It is important to realize a high controllability of all structural parameters to optimize the electrochemical properties of supercapacitors. In order to solve these challenges, novel functional nanostructures and material compositions (and related fabrication processes) need to be developed. An attractive solution is offered by preparing large-scale arrays of one-dimensional (1D) core/shell nanostructures including nanowires and nanotubes. Such nano-engineered materials combine the unique properties of two materials (i.e., core and shell). Usually, the highly conductive core provides a fast electron transport through the entire electrode and the thin shell ensures a good utilization of the energy storage material and a short ion diffusion. Template-based techniques are efficient methods

to prepare large-arrays of 1D nanostructures, especially for core/shell structures. However, the level of controllability of the template-based techniques is partially limited to a few parameters and largely depends on the inherent structural nature of the template itself. Atomic layer deposition (ALD), as an efficient process to prepare conformal films or tubular structures, provides a good solution to further adjust more structural parameters.We demonstrate [4] an innovative technique to realize highly ordered free-standing three-dimensional (3D) arrays of SnO2/MnO2 core/shell nanotubes with precise controllability of structural parameters. Advanced core/shell nanostructures including open-end and closed-end nanotubes are achieved, so as to investigate and optimize the electrochemical mechanism for supercapacitor applications. Very importantly, based on the property optimization of the 3D core/shell nanostructures, we obtained an electrochemical performance that is among the highest reported values for MnO2-based nanostructures. Moreover, we recently realized a complete 3D nanostructured asymmetric supercapacitor based on PPy and MnO2 [5]. This asymmetric cell design increases the possible operating potential window to 1.7 V, which is a major leap to enhance the specific energy of supercapacitors. The prepared device exhibits a high specific energy of 27.2 Wh kg-1 and a high specific power 24.8 kW kg-1.

F. Grote, R. Vellacheri, Y. Lei

Three-dimensional core/shell nanotube arrays for high performance supercapacitors

Fig. 2: Electrochemical performance of NT array. a) CV curves; b) Specific capacitance and rate capability

Fig. 1: a) Scheme of core/shell NT array; b) Cross-section SEM image of NT array; c) TEM and EDX line scan of single NT





[1] L. Y. Liang, Y. M. Xu, Y. Lei, H. M. Liu, Nanoscale 6, 3536 (2014).

[2] Y. Lei, S. K. Yang, M. H. Yu, G. Wilde, Chem. Soc. Rev. 40, 1247 (2011).

[3] Y. Lei, W. P. Cai, G. Wilde, Progress in Materials Science 52, 465 (2007).

[4] Y. Xu, E. M. Lotfabad, H. L. Wang, B. Farbod, Z. W. Xu, A. Kohandehghan, D. Mitlin, Chem. Commun. 49, 8973 (2013).

Planar thin-filmed rechargeable ion batteries have a relatively low volumetric capacity because relatively much volume is occupied by inactive materials such as substrate and packaging. To increase the volumetric energy density of these batteries, three-dimensional (3D) geometries can be applied, for which with almost the same amount of packaging and substrate material much higher energy storage capacities can be obtained. As a result, 3D nanostructured electrodes unambiguously play a crucial role with the following aspects being beneficial:(1) Providing large surface area to boost the electrochemical reaction occurring at the solid-liquid interface.(2) Offering open space to accommodate the volume change and more ions.(3) Giving rise to direct throughout pathway and/or porous structure to facilitate the electron or ion transport and electrolyte diffusion, so as to ensure the electrochemical reaction proceeding with high efficiency.Several concepts have been proposed for a 3D nanostructured configuration and our group has been focusing on the ones based on aerogels and templates.1. An aerogel is a solid-state material with the structure of a randomly oriented solid-state network that consists in large part of open volume, often as much as 75-99%. By using a facile one-step hydrothermal method assisted by a freeze-drying process, we in-situ integrated 1D AgVO3 nanowires

and 2D graphene nanosheets to create the innovate 3D aerogels with hierarchical macro-porous interconnection (Fig. 1a).[1] When used as cathode materials for rechargeable lithium ion batteries, the 3D composite aerogels exhibited the initial discharge capacities of 195.8 mA h g-1 (50 mA g-1), 166.5 mA h g-1 (400 mA g-1), and 143.9 mA h g-1 (1 A g-1) (Fig. 1b), showing rather competitive capacities and high retention (73.5%) at high current densities. Long-term cycling measurements further indicated the advantages of 3D configuration by improving the electrical conductivity and Li+ diffusion rate of the electrode system.2. 3D nanostructure can be formed onto a planar substrate using anodic aluminum oxide (AAO) template-based method, which highlights the second concept of 3D configuration that we are focusing on.[2,3] We successfully fabricated Sb nanowire arrays and TiO2/Ni core-shell nanorod arrays with large area and high throughput by using AAO template technique (Fig. 2). The size and spacing of the as-prepared nano-unit can be precisely controlled by changing the geometrical structure of the template, and the well-aligned feature can be ensured by the regularity of the template. When used as anode materials for rechargeable sodium ion batteries, the preliminary results showed that the long-term cyclability and rate capability of the TiO2/Ni core-shell nanorod arrays are among the best in light of the previously reported works regarding this material.[4]

Y. Xu, L. Y. Liang, Y. Lei

Three-dimensional nanostructures for the performance enhancement of rechargeable ion batteries

Fig. 2: SEM images of Sb nanowire arrays (a) and TiO2/Ni core-shell nanorod arrays (b) fabricated by AAO template

Fig. 1: (a) SEM image of 3D aerogels. (b) The first charge-discharge profiles at various current densities

DEVICES

Contact


166


Fig. 2: Images of an USAF test chart with (a) different anamorphic factors and (b) different zoom factors for an anamorphic factor of 1

Fig. 1: Setup of the anamorphic imaging system with four cylindrical lenses on LTCC modules.


DEVICES

167

Contact

1 Optical Engineering Group2 Micromechanical Systems Group

Funding: German Research Foundation (DFG), SI573/7-2 and

HO2284/1-2

Daniel Pätz | +49 3677 69-1806 | [email protected]

[1] S. Leopold et al. "Tunable cylindrical microlenses based on aluminum nitride membranes ", Proc. SPIE 8616, MOEMS and

Miniaturized Systems XII, 861611 (2013).

[2] D. Pätz et al., "Tunable Anamorphotic Imaging System based on Fluidic Cylindrical Lenses," in Microlenses, Proc. OMN

2014, paper MOp3�4�

IntroductionAnamorphic imaging systems are generally based on cylindrical lenses to realize different magnification factors in x- and y-direction. Common applications are cinema imaging and projection systems which use the standard film format to capture and project wide screen sceneries. Tunable anamorphic systems usually change only one dimension of the image to adapt the aspect ratio. We realized an anamorphic micro system with a tunable magnification factor in both directions. Those systems can be applied to increase the effective resolution of objects with different geometries by adapting the aspect ratios of the images to the sensor size. Another field of application is beam shaping of asymmetric laser beams to optimize laser machining processes.Optical System DesignConventional zoom systems are based on two optical components with variable axial-position to adjust focal power and image position. In contrast we used two perpendicularly oriented pairs of tunable cylindrical lenses to realize the tunable magnification in x- and y-directions. We apply fluidic membrane lenses made of aluminum nitrid (AlN) to achieve a highly dynamic and stable system. With

an optimized membrane geometry we achieve a cylindrical surface profile and minimize the lateral size of the lenses [1]. The aperture size of the lenses is 3x3 mm2. The design of the anamorphic system is significantly restricted by the required range of magnification and the tuning range of the fluidic lenses [2]. For a reasonable focal length of f' = 35 mm … ∞ and a magnification range of β'=-0.5 … -2.0, the minimum system length is 157.5 mm.ExperimentsFigure 1 shows the demonstrator setup with four cylindrical lenses as well as fluidic connection for filling and actuation. The lenses are mounted on modules of Low Temperature Cofired Ceramics (LTCC) with integrated fluidic channels. Thus closely spaced lenses can be realized to achieve a compact design and reduce stray light within the immersion fluid. Figure 2a demonstrated the optical performance for three different anamorphic factors. With a corresponding actuation of the four lenses the system can also operate as a classical zoom system with uniform magnification in both directions (see Figure 2b). The strong vignetting towards the edges of the images are caused by the large axial distance of the optical components and can be reduced by increasing the optical power of the lenses.

D. Pätz1, S. Leopold2, M. Hoffmann2, S. Sinzinger1

Tunable anamorphic imaging system based on cylindrical AlN-membrane lenses

Fig. 2: 3D scaffold cultures of primary hepatocytes

Fig. 1: The microporous 3D scaffold houses the cells

Fig. 3: Hepatocyte donor information

Fig. 4: n-fold gene expression in 3D cultures (2D= 1)

Contact


168

Funding: FKZ03ZIK062, FKZ03ZIK465, FKZB714-09064

SYSTEMS INTEGRATION & APPLICATIONS


Uta Fernekorn | +49 3677 69-3486 | uta�fernekorn@tu-ilmenau�de

[1] B. Vinci, C. Duret, S. Klieber, S. Gerbal-Chaloin, A. Sa-Cunha , S. Laporte, B. Suc, P. Maurel, A. Ahluwalia, M. Daujat-

Chavanieu, Biotechnology Journal, 2011, 6, 554�

[2] A. Burkard, C. Dähn, S. Heinz, A. Zutavern, V. Sonntag-Buck, D. Maltman, S. Przyborski, N.J. Hewitt and J. Braspenning.

Xenobiotica, 2012, 42, 939

[3] E�C� Butcher, Nature Reviews Drug Discovery, 2005, 4, 461�

[4] Godoy, P., Hewitt N.J., Albrecht, U., Andersen, M. E., et al., Arch. Toxicol. 2013, 87, 1315-1530.

The development of reliable systems for testing new compounds for use in the pharmaceutical industry has been a challenging task to date and the concept of a 3D, organotypic cell culture is emerging as a serious alternative to 2D cell cultures or animal testing. We developed a biocompatible 3D cell culture environment that enables continued existence of cells in a polycarbonate scaffold structure optionally housed in a perfusable bioreactor system. To survey maintenance of metabolic function, an experimental duration of five days was chosen to evaluate the system for short term applications. Primary hepatocytes were obtained from human liver biopsies mostly related to a medical history related to carcinoma. The cells were prepared with informed consent of the patients and with approval of the local ethical committee. Hepatocytes were cultivated under 2D, 3D static and perfused conditions. After five days, total RNA was isolated from the cells at SIRS- Lab GmbH, Germany. RNA samples of hepatocyte cultures and an internal control RNA were hybridized on two HumanHT-12 v4 Expression BeadChips. Whole genome expression analysis was performed utilizing Illumina Ingenuity pathway analysis (IPA). Fold change gene expression within 3D cultures were set in relation to 2D expressions which were set as point of reference with the value of 1. Gene networks proposed by IPA show a more pronounced

network activity regarding metabolic reactions in perfused 3D hepatocyte cultures while the static cultivation evokes a genotype more related to cellular functionality. We also directly analyzed gene expression levels of the enzymes and relevant hepatic markers from the data set. The major phase I metabolizing enzymes such as CYP3A4 and CYP3A7 were remarkably upregulated when the cell culture was perfused. In all experiments, upregulation of the gene coding for vascular endothelial growth factor was noted. For the evaluation of cytologic parameters under 3D cultivation conditions, four individuals were assayed. Cell numbers in the 3D cultivation form remained almost constant for the period the experiment was run. Analysis of metabolic and proteomic parameters is readily amenable via a sample port integrated in the device. The MatriGrid based 3D cell culture is capable to cultivate human hepatocytes at good vitality. With respect to their biotransformation capability, we hypothesize that a perfused 3D culture creates better conditions for maintenance of primary hepatocytes. However, metabolic output differs vastly between individual patients. The authors hypothesize that a reason for this could be a difference in the medical history of the donors. For more standardizable experiments with human hepatocytes, we propose the use of a hepatocyte model immortalized by transduction procedures.

U. Fernekorn, J. Hampl, F. Weise, M. Klett A. Läffert,

K. Friedel, A. Schober

Assessing the 3D in vitro physiology of biopsy derived primary hepatocytes

Fig. 2: Brückner oscillations during Si removal at Si(100) 0.1°

Fig. 1: A-type Si(100) 2° with dimer rows parallel to step edges

Fig. 3: RAS of (2x2)/c(4x2) reconstructed GaP(100) with P dimers

Fig. 4: Dimer orientations and sketch of abrupt Si-P interface



169

Contact

Photovoltaics Group

Funding: DFG (HA3096), BMBF (03SF0404A)

Thomas Hannappel | +49 3677 69-2566 | thomas�hannappel@tu-ilmenau�de

[1] T. Hannappel, S. Visbeck, L. Töben, F. Willig, Rev. Sci. Instrum. 75, 1297 (2004).

[2] S. Brückner, H. Döscher, P. Kleinschmidt, O. Supplie, A. Dobrich, T. Hannappel, PRB 86, 195310 (2012).

[3] S. Brückner, P. Kleinschmidt, O. Supplie, H. Döscher, T. Hannappel, New J. Phys. 15, 113049 (2013).

[4] P. Sippel, O. Supplie, MM. May, R. Eichberger, T. Hannappel, PRB 89, 165312 (2014).

[5] O. Supplie, T. Hannappel, M. Pristovsek, H. Döscher, PRB 86, 035308 (2012).

IntroductionTandem absorber structures based on III-V top and Si bottom cells promise high efficiencies for both photovoltaics and solar water splitting. MOVPE allows industrially scalable production of the desired structures. The process gas, however, limits in situ process control to optical techniques. As such, reflection anisotropy spectroscopy (RAS) is highly sensitive to surfaces of cubic crystals, and a patented MOVPE-to-UHV transfer system allows us to relate the complex optical RA spectra to electron-based techniques like STM, UPS/XPS, LEED and two-photon photoemission spectroscopy (2PPE) as well as virtually any remote measurement station which supports an adequate carrier handling, for example at BESSY [1]. With this unique setup, we can understand the origin of the RA spectra and subsequently use them to control the atomic order at surfaces precisely during processing. This is highly important at surfaces since their reconstruction influences device performance. Especially in the case of heteroepitaxy, this approach allows for the preparation of well-defined interfaces with low defect densities. An intuitive example is anti-phase disorder in zinc-blende III-V epilayers which is induced by monatomic steps at group IV substrates like Si (in particular at {100} faces which are of interest due to CMOS integration) and can be avoided by single-domain Si(100) surfaces [2].

O. Supplie, S. Brückner, A. Dobrich, P. Kleinschmidt,

T. Hannappel

Atomic scale control of Si and III-V surfaces and interfaces by UHV-benchmarked in situ spectroscopy

ResultsAbove 700°C, the carrier gas H2 strongly interacts with Si(100) surfaces leading to vacancy generation by Si atom removal via SiHx species [2,3]. These vacancies diffuse preferentially along dimer rows [2]. Their annihilation at step edges creates almost single-domain surfaces in case of narrow terraces [2, Fig. 1] with a characteristic RA spectrum enabling optimization of surface preparation. Vacancy islands form on wider terraces promoting layer-by-layer removal which causes oszillations in time-resolved monochromatic RA measurements at energies where dimer-related features occur [3, Fig. 2]. Dependent on the (Ga,P) chemical potentials and temperature, GaP(100) surfaces reconstruct either (2x4) with a mixed Ga-P dimer on top of a Ga layer or (2x2)/c(4x2) with buckled P dimers stabilized by one H atom each. By benchmarking the RA spectra to 2PPE, we can discriminate GaP(100) surface from GaP bulk states and could experimentally assign a sharp peak in the (2x2)/c(4x2) related RA spectrum (Fig. 3) to a transition from a bulk to a P dimer related state [4]. The orientations of these P dimers corresponds to the sublattice orientation of the GaP bulk. The correlation of Si dimer orientation prior to GaP growth and GaP sublattice orientation in combination with density functional theory agrees with a kinetically limited model of abrupt Si-P interface formation [Fig.4, submitted]. The existence of Si-P bonds also explains an interface related anisotropy we reported in [5].

RF and Microwave Research Group

Funding: Federal Ministry for Economic Affairs and Energy,

project management by the German Aerospace Center (DLR,

50YB1303)

Steffen Spira | +49 3677 69-1283 | steffen�spira@tu-ilmenau�de

[1] H. Chan, “Advanced Microwave Technologies for Smart Flexible Satellite,” in IEEE MTT-S International Microwave

Symposium Digest, pp� 1-4, Baltimore, 2011�

[2] S. Humbla, S. Kaleem, J. Müller, S. Rentsch, R. Stephan, D. Stöpel, G. Vogt, M.A. Hein, ”On-orbit verification of a 4 × 4

switch matrix for space applications based on the low temperature co-fired ceramics technology,” in Frequenz, 66 (11-12),

pp� 355-362, 2012�

St. Spira, A. Ebert, S. Humbla, M. A. Hein

Broadband Amplitude Steering Microwave Block Utilising LTCC Technology

Advanced satellite communication systems require more and more functionality, flexibility, and reconfigurable payload modules [1]. A high level of hybrid integration, functional complexity, reliability, and space qualification can be achieved by implementing such functions on multilayer low-temperature cofired ceramics (LTCC). The KERAMIS® technology, developed in the IMN MacroNano with industrial and academic research partners, is approved for truly three-dimensional advanced microwave modules even in the Ka-band satellite downlink frequency range of 17 - 22 GHz [2]. Vectorial signal processing is a common architecture used, for instance, for beam forming antennas. A building-block for controlling the amplitude of a signal forms the first step towards the design of a more elaborated multiple-way module for signal conditioning purposes.Fig. 1 shows the assembled amplitude steering block. The substrate was made from DuPont 951 Green Tape™. The thickness of the green tape measures 254 µm. The basic sub-circuits consist of matching networks at input and output (#1 and #4 in Fig. 1), a low-noise amplifier (#2), and a digitally controllable attenuator (#3). The amplifier features a gain of 20 dB and provides an isolation and loss compensa-

tion functionality. The 5-bit attenuator yields an adjustable attenuation range of 15.5 dB with 0.5 dB resolution. The monolithic microwave integrated circuits are assembled as dies in one shared cavity embedded in the LTCC module. This advantage of the LTCC-technology allows for reduced bonding wire lengths and improved electrical grounding conditions. An essential design step constitutes the numeri-cal calculation of the transitions between the MMICs and the adjacent substrate by means of three-dimensional electromagnetic full-wave simulation. The degradation of the circuit performance caused by the bonding elements could be reduced by the use of bonding ribbons. Measure-ments of the broadband amplitude steering block showed an input return loss not less than 10 dB and an output return loss better than 12 dB over the rated frequency range from 17 GHz to 22 GHz. The results for the forward transmission are shown in Fig. 2 for various attenuator states 1 dB apart and corrected for the mean gain value of 17.7 dB at the 0-dB state. The slightly descending frequency response near 22 GHz originates from a too low cut-off frequency chosen for the input and output networks and can be resolved simply easily in subsequent versions.

Fig. 2: Measured forward transmission at the attenuator states from 0 dB to 15 dB at 1 dB step size

Fig. 1: Assembled amplitude steering block


Contact


170

Fig. 2: SEM image of the released cantilever

Fig. 1: Schematic of cavity optical transducer for SPM

Fig. 3: Output of optical cavity transducer when driven by integrated actuator. Maximum signal corresponds to a deflection of 2 nm



171

Contact

1 Center for Nanoscale Science and Technology, Gaithersburg,

USA2 Micro- and nanoelectronic Systems Group Funding: National Institute for Standards and Technology,

FP7/2007 - 2013, GA 318804

Ivo Rangelow | +49 3677 69-3718 | Ivo�rangelow@tu-ilmenau�de

[1] H. Miao et. al., New Journal of Physics 14, (2012)

Research and development of transducers based on cavity optomechanics is a topic of high interest particularly because these transducers enable measurement of mechanical motion down to the fundamental limit of precision imposed by quantum mechanics. We have developed an on-chip cavity optomechanical transducer platform that combines high bandwidth and sensitivity near the standard quantum limit with compactness, robustness, small size, and potential for low cost batch fabrication inherent in MEMS [1]. We present design and implementation of a fully integrated and fiber pigtailed sensor for atomic force microscopy. The device combines high sensitivity, high bandwidth optomechanical readout and built-in thermal actuation. It is implemented by a microfabrication process combining one e-beam patterning and 10 optical lithography steps to define silicon nitride torsional cantilever, single crystal silicon-on-insulator (SOI) microdisk optical cavity with high optical Q, SOI optical waveguides, as well as a patterned gold layer for electrically driven thermal actuation. Back and

front side anisotropic potassium hydroxide (KOH) silicon etch is used to overhang the cantilever over the edge of the silicon chip and to define v-groves for single mode optical fiber attachment. Two sacrificial silicon dioxide layers are removed by an isotropic hydrofluoric acid (HF) etch to free the mechanically movable structures. The SiN torsional oscillator can be excited by an electrical signal supplied to an integrated thermal actuator. The oscillator is evanescently coupled to a high-Q whispering gallery mode of the optical cavity, and the motion is detected by measuring the resonance frequency shift of the mode. One side of the oscillator probe overhangs the edge of the chip, where it can be easily coupled to a variety of off-chip samples and physical systems of interest. A 10 μm long probe is currently designed to have a stiffness of 1 N/m to 3 N/m and a resonance frequency of 100 kHz to 2.5 MHz, while the design can be easily and broadly tailored for specific sensing applications.

T. Michels1,2, J. Zou1, H. Miao1, V. Aksyuk1, I.W. Rangelow2

Cavity optical transducer for scanning probe microscopy


Funding: Federal Ministry of Education and Research, Grant

No� 16SV5473

Andreas Schober | +49 3677 69-3387 | [email protected]

[1] Lee W.M., (2003), Drug-induced Hepatotoxicity. N Eng J Med 349, 474-85.

[2] Leite S� B�, Wilk-Zasadna I�, Zaldivar J� M�, Airola E�, Reis-Fernandes M� A�, Mennecozzi M�, Guguen-Guillouzo C�, Chesne

C., Guillou C., Alves P. M. and Coecke S. (2012). Three-Dimensional HepaRG Model As An Attractive Tool for Toxicity Testing.

TOXICOLOGICAL SCIENCES 130(1), 106-116.

Currently there is no automated test system available for a fully automated 3D-perfusion culture of hepatocytes combined with a simultaneous online-monitoring of the toxicity of the applied drug. To circumvent this problem, a complex system concept was developed, which enables automated perfusion 3D cell culture, automated medium change and repeated drug application, automated sampling from the cultivation system and a non-cell-bound toxicity test system. Prior to the application of the device, 3D-cultivation was compared with conventional 2D-cultivation of hepatocytes. DMSO-differentiated 3D-grown HepaRG hepatoma cells showed a stronger polarization than 2D-grown cultures. These results were accompanied by elevated levels of drug transporter activity and bile canalicular structures (Fig. 1). Sensitivity of perfused differentiated 3D-grown HepaRG cells to the drug acetaminophen was remarkably higher than that of 2D grown cultures (Fig. 2) making them more appropriate

for online-toxicity studies. Fig. 3 shows the complete system for online drug toxicity testing consisting of a cultivation unit and the analysis unit. The cultivation system comprises a bioreactor containing the MatriGrid scaffold for 3D-hepatocyte cell culture and the supporting bioreactor unit containing the pump, solenoid valves and containers for the cell culture medium. The purpose of analysis unit is to measure soluble albumin, secreted by the HepaRG cells by an automated flow through Enzyme linked immunosorbant assay (ELISA). This system works in real time and is capable of simultaneous generation of a standard curve. Finally, albumin secretion of HepaRG cells in response to long term acetaminophen (Paracetamol) – treatment was investigated with the cultivation and analysis system. As a result, the well-known hepatotoxicity of acetaminophen, accompanied by falling albumin levels, could be verified with this system (Fig. 4).

D. Kürsten, M. Baca, U. Fernekorn, M. Klett, J. Hampl, A.

Läffert, A. Groß, S. Singh, K. Friedel, A. Schober

Cultivation and Analysis System for the Evaluation of Drug Toxicity to the Liver

Fig. 2: 3D HepaRG cultures are more susceptible to acetaminophen

Fig. 1: 2D and 3D HepaRG hepatocytes compared in terms of polarity

Fig. 3: control unit and cultivation- and analysis system

Fig. 4: online -albumin ELISA a 3D liver cell cultures


Contact


172

Fig. 1: Schematic illustration of a four point measurement performed to obtain the resistance profile along the nanowire



173

Contact

1 Photovoltaics Group2 Jülich Research Centre3 University Duisburg Essen

Funding: BMBF INPV003


[1] S. Korte, M. Steidl, W. Prost, V. Cherepanov, B. Voigtländer, W. Zhao, P. Kleinschmidt, and T. Hannappel, “Resistance and

dopant profiling along freestanding GaAs nanowires,” Appl. Phys. Lett., 103, 14 (2013).

Nanowire-based devices have been proposed for a variety of applications in electronics and optoelectronics, ranging from single-nanowire field-effect transistors (FETs) through all-round gate control in FETs to solar cells with core-shell p-n structure. All these devices rely on the electronic properties of the nanowires and utilize them in a range of configurations. Therefore, studying these nanowire properties is essential for any related applications.Investigations of individual nanowires provide essential information for device development, but are technically quite demanding. The determination of the local resistivity and transport data in nanowires in most cases was realized by detaching the nanowires from the surface and incorporating them into specific test devices utilizing ultra-high precision lithography. Due to the limitations of this method, the electronic properties of the nanowires can only be investigated in a small number of configurations. Additionally, these kinds of experiments are quite time consuming, and the method is not able to provide crucial information at the interface between nanowire and substrate.In contrast to the conventional methods, a multi-tip scanning tunneling microscope (MTSTM) with an integrated SEM column provides an ideal technical combination to investigate electrical properties of nano-scale structures such as as-grown nanowires. The 4 independent STM tips can be individually configured as current- or voltage-supplies or probes. The piezo-positioners on each tip and on the sample carrier enable three dimensional ultra-precise nanometer scale movement over a range of several millimeters. Additionally, two piezo-controlled optical fibers are included in the system, which enable the study of the optoelectronic properties of a single nanowire. Furthermore, the MTSTM is mounted in a cryostat allowing all of these experiments to be performed at low temperatures down to 10 K.Recently, we carried out four-point probe measurements on freestanding Zn-doped GaAs nanowires grown on n-Type

GaP(111) substrates with our MTSTM (schematic illustration in Fig. 1a). One tip was used to contact the end of the nanowire and apply a current through the wire (with the substrate being grounded). Two other tips were positioned at the nanowire to sense the potential. We varied the position of one of these tips (tip 3) while the other (tip 2) was kept at the same position near the top of the nanowire. Measuring the voltage drop between the two tips and the current, a resistance profile along a single nanowire was obtained as shown in Fig. 1b).Unlike the conventional method, where the nanowire is removed from the substrate, the high resolution measurement with the MTSTM reveals that the resistivity in the nanowire base exceeds the top part of nanowires by several orders of magnitude. The higher resistivity of the base of the nanowire is attributed to lower doping at the start of the growth process. These results suggest that the growth temperature and precursor supply have to be adjusted for applications which rely on vertical, freestanding III-V nanowires.

W. Zhao1, S. Korte2, M. Steidl1, W. Prost3,B. Voigtländer2,

P. Kleinschmidt1, T. Hannappel1

Electrical characterization of as-grown, freestanding nanowires using a multi-tip scanning tunneling microscope

1 Photovoltaics Group2 University Duisburg Essen Funding: BMBF INPV00

Matthias Steidl | +49 3677 69 4938 | matthias�steidl@tu-ilmenau�de

[1] S. Korte, M. Steidl, W. Prost, V. Cherepanov, B. Voigtländer, W. Zhao, P. Kleinschmidt, and T. Hannappel, Appl. Phys. Lett.,

103, 14 (2013).

IntroductionIII-V nanowires (NW) are of increasing importance not only for future optoelectronic devices such as LEDs, optical sensors and high efficiency solar cells, but also for microelectronics and light-induced water splitting. Their specific geometry and high aspect ratio allows increased light absorption and enhancement of chemical reactions at the surface compared to planar structures with lower material consumption. Moreover, III-V NWs could be combined with established Si microelectronics technology. However, several difficulties arise when growing directly on Si: the stability of the native oxide from Si, the strong Au-Si chemical interaction and unintentional doping of the NW. One strategy to overcome these problems is to grow a III-V buffer layer on the Si substrate ensuring a chemical separation between Au and Si. Since GaP is almost lattice-matched to silicon, we developed GaP/Si(111) quasisubstrates for the subsequent growth of GaAs NWs.ExperimentalAll samples were prepared in a horizontal-flow, low-pressure, commercial MOVPE reactor (Aixtron AIX 200) in H2 ambient. To enable characterization of sample surfaces by UHV-based methods, the MOVPE system is enhanced by a contamination-free MOVPE-to-UHV transfer system. Following preparation in the MOVPE environment, the samples were transferred to dedicated UHV chambers

for specific surface characterization techniques. Surface reconstructions were determined by LEED, the chemical composition of the samples was studied by XPS, and XRD was utilized to determine the thickness of GaP grown on Si(111). The surface morphology was analyzed ex-situ by AFM. To investigate hydrogen bonds on the silicon surface, a FTIR spectrometer was used for measurements in an ATR configuration. Scanning electron microscopy (SEM) was applied to investigate the NW morphology. Our standard silicon process results in oxygen- and contamination-free Si(111) with a (1x1) surface reconstruction, monohydride bonds and an atomically flat surface suitable for subsequent GaP growth. However, LEED studies showed that direct growth of GaP on Si results in GaP(111)A-type polarity, unsuited for nanowire growth. We achieved growth of the desired GaP(111)B-type polarity by treating the Si surface with arsenic prior to GaP deposition. On these quasisubstrates we demonstrated growth of GaAs NWs by the vapor-liquid-solid growth mode using Au-nanoparticles as catalysts. Applying a two-temperature growth sequence with 450°C for the NW bottom and 400°C for the upper NW resulted in NWs normal to the surface with little tapering. We investigated the electrical properties of Zn-doped GaAs NWs employing a 4-tip-STM as a nanoprober. The measurements revealed a low doping level within the NW bottom (2e17 cm-3) and a high doping in the upper NW part (8e18 cm-3) [1].

M. Steidl1, W. Zhao1, A. Paszuk1, S. Brückner1, A. Dobrich1,

P. Kleinschmidt1, W. Prost2, T. Hannappel1

Growth of GaAs Nanowires on Si(111) by Using GaP Buffer Layers

Fig. 1: (a) Scheme of GaAs nanowires on Si(111) with a GaP buffer layer (b) Experimental results for UHV-based methods (c) Zn-doped GaAs nanowires on GaP(111)B


Contact


174



175

Contact Siegfried Stapf | +49 3677 69-3671 | siegfried�stapf@tu-ilmenau�de

[1] T. Joseph, J. Delaney, A.R. Liberski, J. Perelaer, U.S. Schubert, Macromol. Rapid Commun., 31: 1970 (2010)

[2] T. Torimoto, T. Tsuda, K. Okazaki, S. Kuwabata, Adv. Mater., 22: 1196 (2010)

[3] O. Kimn T. Shin, M. Park, Nat. Commun., 4: 2208 (2013).

Funding: Landesgraduiertenstipendium


Electroactive actuators have gained considerable attention for various applications of biomimetic technologies ranging from robotics and micro-/bio-sensors to artificial muscles. This class of material has been mostly fascinating for electrochemists, and they were initially designed for solid-state polyelectrolyte [1]. Preparation of electroactive polymeric materials using biopolymers and ionic liquids opens a promising field of research. Ionic liquids have been widely studied during the last decade, due to their interesting physiochemical properties. They are composed entirely of ions, and they usually show very low vapour pressure. These features facilitate the preparation and maintenance of the ionic liquid based biopolymeric films, i.e. gelatine mixed with ILs which form durable polymeric films with good mechanical strength, conductivity [2], and some of them have the ability to respond to an external electrical stimulus [3].

Different nuclear magnetic resonance (NMR) techniques are employed in order to elucidate the molecular dynamics of the gelatine biopolymer and reveal the remarkable role of ILs inside the soft gel pores. Different research papers tackle various compositions of polymers and ILs so as to obtain polymeric films with more conductivity or more sensitive to external stimuli. These works mostly consider structural investigations though.The single-sided NMR scanner enables us to get information on different nuclei at different depths of the sample. This is particularly advantageous in ionic liquid studies because many of them contain 1H and 19F nuclei. For instance, 1-ethyl-3-methylimidazolium tetrafluoroborate is an ionic liquid with a structure shown below. Interestingly, the cations contain 1H nuclei while anions have 19F. This makes the molecular dynamics study of specific ions feasible.

A� Ordikhani-Seyedlar, C� Mattea

Ion-Jelly: Towards the Molecular Dynamics of conductive materials and Electroactive Actuators using NMR methods

Fig. 2: Profile of the distribution of anion and cation of the shown ionic liquid in a thin gelatin film

1000 1500 2000 2500 3000 3500 4000

0

20

40

60

80

19F Signal

NMR

signa

l (ar

b. u

nits

)

height (µm)

0.8g 0.6g 0.4g 0.2 g

1H Signal

Fig. 1: Scheme of macroscopic deformation of a membrane due to a potential difference

1 Photovoltaics Group2 Helmholtz Zentrum Berlin


[1] A.J. Ptak, D.J. Friedman, S.R. Kurtz, R.C. Reedy, J. Appl. Phys. 98 (9) (2005) 094501.

[2] B. E. Sağol, U. Seidel, N. Szabó, K. Schwarzburg, and T. Hannappel, Chimia, vol. 61, no. 12, pp. 775–779, (2007).

[3] G� Létay,A� W� Bett, Proc�17th EU PV Sol� En� Conf� 2001, 178�

[4] F. Dimroth, … A. Dobrich, T. Hannappel, and K. Schwarzburg, PIP Res. Appl., vol. 22, no. 3, pp. 277–282, Mar. 2014.

Exceeding photovoltaic conversion efficiencies well beyond 40% under concentrated sunlight, III-V multi junctions constitute by far the most efficient type of solar cells today. The multi junction approach opens the way to harvest low, medium and high energy photons of the solar spectrum while largely reducing inherent thermal and optical losses. By tuning the composition of ternary and quaternary III-V alloys, a wide range of band gaps and optimum optical properties are available. III-V’s can be grown industrially scalable with an excellent material quality in metalorganic vapor phase epitaxy (MOVPE), where also the involved heterointerfaces can be prepared atomically sharp. Triple junction III-V cells are not only state of the art for space applications: Combined with concentrating optics, they are commercially available for terrestrial application with conversion efficiencies significantly beating the single band gap (Shockley-Queisser) limit. While high band gap material combinations lattice matched (LM) to GaAs or Ge are well established, calculations show that a band gap in the range of 1eV is highly desirable for further increasing the conversion efficiency. However, GaInAsN today is the only candidate exhibiting LM to Ge/GaAs, but its transport properties are not yet sufficient for solar cell applications [1]. We came up with the idea to replace the bottom Ge subcell by a GaInAsP/GaInAs double junction bottom cell with low band gaps to create a four-junction (4J)

solar cell with a well-established GaAs/GaInP tandem top cell [2]. The bottom tandem is designed LM to InP and could be combined with the top tandem by means of metamorphic growth, mechanical stacking, wafer bonding, or separation of the solar spectrum [2].Figure 1 left shows calculations of conversion efficiencies for such a mechanically stacked 4J solar cell using EtaOpt [3]. The conversion efficiency limit is calculated to 61% for a concentration ratio of 500 suns under Air Mass (AM) 1.5d. The serial connection between the GaInAs bottom and the GaInAsP top cell was realized by employing an Esaki-diode-like tunneling junction of highly n-doped GaInAs and highly p-doped GaAsSb. This asymmetric material combination was used because of their favorable band offsets [2]. The growth parameters of that low band gap tandem cell were transferred to project partners*, where the two tandem cells were grown in separate MOVPE processes and connected through a wafer bonding layer afterwards (Fig. 1 right). The resulting GaInP/GaAs//GaInAsP/GaInAs 4J solar cell reached a certified new record efficiency of 44.7% at 297-fold concentration of the AM1.5d (ASTMG173-03) spectrum (Fig. 2) [4]. This work demonstrates a successful pathway for reaching highest conversion efficiencies with III–V multi-junction solar cells having four and in the future even more junctions [4].*Fraunhofer Institute for Solar Energy Systems ISE, Soitec S.A., CEA Leti MINATEC

A. Dobrich1, K. Schwarzburg2, T. Hannappel1,2

Low band gap GaInAsP/GaInAs tandems for record photovoltaic energy conversion exceeding 44%

Fig. 2: (left) IV curve of GaInP /GaAs//GaInAsP/GaInAs solar cell (right) IV characteristics under concentration for this solar cell [4]

Fig. 1: (left) PV efficiency calc. for a fixed GaAs/GaInP top cell variing the bottom cell band gaps, (right) structure of 4J-solar cell


Contact


176



177

Contact

Funding: German Federal Ministry of Education and Research,

FKZ 16SV5277 O2Sens

Christoph Weigel | +49 3677 69-3378 | christoph�weigel@tu-ilmenau�de

[1] N. Barsan, U. Weimar: Conduction Model of Metal Oxide Gas Sensors. Journal of Electroceramics 7 (2001), Page 143 – 167

[2] H. Reichl: Halbleitersensoren – Prinzipien, Entwicklungsstand, Technologien, Anwendungs-möglichkeiten, Expert Verlag, 1989

State of the art and requirements for oxygen detection in packagingIn numerous product packages the concentration of oxygen is reduced to lower than 1%. An increasing of the oxygen content inside is an indicator for a damaged package. That will lead to deterioration or growth of aerobe organism in foods. The intent is to develop an oxygen sensor which indicates whether oxygen is present inside the package or not. Therefore, a nearly energy-self-sufficient system with an interface for the electrical evaluation without opening the package is needed. State of the art by oxygen sensors are based on metal oxide films, amperometric or parametric sensors. Usually these sensors need partly high temperatures to interact with oxygen [1] or the setup is complex [2]. For safety reasons and system costs in consumer packaging, no battery and energy harvesting devices can be used. Each part of a package, especially in food packaging, must be completely safe even if it is swallowed.Natural materials as transducerIn this context we investigate new materials that safely react with oxygen and thus change electrical parameters without additional external energy supply. Some natural

materials show changes in parameter like color, viscosity or their aggregate state and some without additional external energy. For sensing, we use linseed oil because it is known to react under oxygen containing atmosphere from liquid to solid and change its volume. Linseed oil is used as edible oil and also as ecological coating material. The oxidation rate depends on the concentration of oxygen, the humidity and the coating thickness [3]. Off radical fatty acid arise non-radical products as a stable final condition. A manipulation of the electrical parameter is not possible without destroying the sensitive film. This allows a single-use, biocompatible and low-energy-sensor.With a defined measuring setup, we could demonstrate the relative change of capacity, which is -20% after 5 hours and -38% after 30 hours under an oxygen concentration of 20.5% and 50% relative humidity. Under nitrogen atmosphere, no significant change of the electrical parameters was found over a long period of time. By using a capacitive measuring structure, the readout can be easily obtained via RFID. This allows analyzing electrical parameter without opening the packaging during mass processing.

C. Weigel, M. Schneider, M. Hoffmann

Low-Energy-Sensor for oxygen detection in packaging

Fig. 2: Time dependent capacity of linseed oil on chip measured with RFID-interface

Fig. 1: Chip with capacitve measuring structure on chip carrier


Funding: CRC 622 "Nanopositioning- and Nanomeasuring

Machines" (FKZ INST273/43-1)

Optical Engineering Group

Ronald Kampmann | +49 3677 69-1849 | ronald�kampmann@tu-ilmenau�de

[1] R. Kampmann, A. K. Chall, R. Kleindienst, and S. Sinzinger, "Optical system for trapping particles in air," Appl. Opt. 53,

777-784 (2014)

IntroductionOptical tweezers have been used for over 3 decades as a powerful tool for micromanipulation with unique properties. In order to benefit from the advantageous characteristics in a more general field of applications optical tweezers are optimized and their functionality is extended. In this report we present an optical system for observation and trapping of small particles in an airborne surrounding.Optical TrappingFor optical trapping and manipulating a micrometer-sized object by use of a single beam gradient trap a highly focused laser beam is necessary. To achieve the highest possible trapping force per input laser power we designed and fabricated a highly adapted optical system. The final trapping system, as shown in fig. 1 (red rays), consist of a beam shaping double axicon and a focusing parabolic mirror. That way the generated trapping forces are much higher than those achieved by just focusing a laser beam to an on-axis focus. For observation we implemented

two imaging optical systems illustrated by the green beam paths in fig. 1. After characterizing the fabricated optical elements as well as the whole optical setup we investigate the potential for trapping particles. There we use experimentally measured caustic measurement data within a simulation toolbox for calculating the achievable optical forces. To experimentally prove the functionality of the optical system we trapped spherical SiO2 particles (Ø=10 μm) within standard atmospheric conditions. Stable holding of particles was possible at a laser power of less than 50 mW [1]. Fig. 2 shows 16 frames, 8 for each observation direction demonstrating the optical holding of a particle (green arrow) while a free particle (red arrow) moves upwards due to turbulences within the test chamber. These experimental results demonstrate stable trapping conditions of the developed optical system. The conformity with the simulation results emphasizes the accuracy of the design process using classical optics design and a ray based optical force simulation tool.

R. Kampmann, S. Sinzinger

Optical tweezer for manipulating microscopic objects

Fig. 2: Sequences of holding a particle (green arrow) observed from perpendicular directions

Fig. 1: Optical setup for trapping and observation of micro sized particles


Contact


178

Fig. 2: Bar graph showing totalized counts over a measurement period of 10 min for low and high dust concentrations

Fig. 1: Principle of a particle detector based on electric field interactions



179

Contact


Funding: European Commission (Grant No. 285037 -

INTASENSE)

Martin Hoffmann | +49 3677 69-2487 | martin�hoffmann@tu-ilmenau�de

Although it is becoming obvious that fine dust exposure poses a high risk on human health, measurements have only been conducted at few locations to date in our daily environment. A reason for this deficit is the lack of suitable and affordable measurement systems, especially for indoor applications. Of special interest are dust particles with a critical dimension of less than 10 μm. They pose the highest risk to human health because they are not filtered out by the respiratory system. By miniaturizing particle detector concepts, point-of-care applications are rendered possible and production costs can be greatly reduced with microsystem fabrication technologies.The key task of the presented research is the development of a non-optical particulate matter detection module. The detection principle is based on a particle-induced discharge. A particle of any kind of material entering a volume of sufficiently high field strength triggers an electrical discharge by distorting the field. The longevity of the detector is compromised by electrode deterioration in the microscopic scale. The energy released even with a single discharge is able to damage the electrodes. This issue is overcome by adopting the dielectric barrier discharge

mechanism. A dielectric barrier covering the electrodes reduces the discharge energy levels to a non-destructive limit. The setup of the particle detector is depicted in Figure 1. Each discharge can still be detected by its related current pulse.It has also been found that precise control of particle speed and trajectory is a key element to make the detector work. If particle speed is too low, charged particles – which are always present in the stream – will deposit on the electrodes. The solution found is a microfluidic Venturi-injector where the detector is located in a channel connecting to the Venturi constriction. A non-linear relation between the suction pressure and applied overpressure at the Venturi inlet enables a simple unclogging procedure.Successful counting of particles is demonstrated with fine dust. A comparison between two measurements with varying dust concentration is shown in Figure 2. A video showing the particle counter in operation can be found on the department’s website or the project website. The key results of the new system design have been condensed into a patent application. Continuation of the research with the prospect of commercialization is being examined closely.

T. Geiling, S. Günther, H. Mehner, M. Hoffmann

Particle-induced discharges for fine dust measurement

1 Photovoltaics Group2 Helmholtz Zentrum Berlin3 CalTech, JCAP, USA Funding: Studienstiftung des deutschen Volkes, US DoE

(DE-SC0004993)


[1] MM. May, HJ. Lewerenz, T. Hannappel, J. Phys. Chem. C 118, 19032 (2014).

[2] MM. May, O. Supplie, C. Höhn, R. van de Krol, HJ. Lewerenz, T. Hannappel, New J. Phys. 15, 103003 (2013).

[3] T. Hannappel, MM. May, HJ. Lewerenz, chapter 9 in: 'Photoelectrochemical Water Splitting: Materials, Processes and

Architectures', pp. 223–265, RSC publishing (2013).

[4] O. Supplie, MM. May, H. Stange, C. Höhn, HJ. Lewerenz, T. Hannappel, J. Appl. Phys. 115, 113509 (2014).

IntroductionRenewable generation of hydrogen has a key role in climate change mitigation: Solar energy stored chemically in H2 bonds enables reliable electricity supply independent from intermittent irradiation and fossil fuels. Moreover, H2 can be transformed in synthetic hydrocarbons to be directly burned as fuel. While wired electrolyzers with huge noble metal electrodes may generate H2 from any power source, wireless conversion from solar energy into H2 bonds by direct photoelectrolysis at the semiconductor:water interface promises higher efficiencies, less usage of non-abundant materials and decentralized application. However, criteria for materials are more complex than for standard PV devices: (i) A minimum photovoltage of about 1.8 V must be generated which favors tandem structures for higher absorption efficiencies. Since (ii) water is not split at the maximum power point, more photovoltage is not beneficial while the current density should be as high as possible. (iii) Band alignment with respect to the redox potential of water is crucial. (iv) Corrosion of the cell in the electrolyte has to be minimized. Dilute nitride GaP-based top cells on Si(100) are promising candidates.

O. Supplie1, MM. May2, HJ. Lewerenz3, T. Hannappel1

Towards III-V/Si(100) tandem absorbers for high-efficent photoelectrolysis

ResultsTo analyze the initial interface formation in liquid environments, homoepitaxially grown InP(100) [1] and GaP(100) [2], as reference surfaces, were exposed to water vapor in UHV while monitoring surface changes with reflection anisotropy spectroscopy (RAS). The surface reconstruction has a high impact: P-rich, (2x2)/c(4x2) reconstructed GaP(100) is more stable than Ga-rich (2x4) surfaces and shows a new c(2x2) super structure after water exposure [2].Incorporation of only 2% of N into GaP drastically reduces the band gap, turns it direct-like and leads to lattice matching to Si (Fig.1). The bandgap combination of GaPN and Si is close to optimum for tandem absorbers, and the band alignment allows both H2 and O2 evolution [3,4]. Adding As would further reduce the bandgap. N also stabilizes III-V surfaces. However, N incorporation is known to decrease crystal quality, probably due to imperfect growth. By comparing GaP/Si(100) and GaPN/Si(100), we found that Ga-rich surfaces may be prepared analogously, while excess N must be avoided for preparation of well-ordered group V rich surfaces. RAS signals of both GaPN surfaces show additional features that we attribute to N incorporation into the GaP bulk [4, Fig. 2], which is promising in order to study the effect of N in situ.

Fig. 2: RAS of Ga-rich, (2x4) reconstructed GaP0.98N0.02 grown lattice matched on Si(100). The inset magnifies a N related contribution.

Fig. 1: Bandgap vs. lattice constant for III-V compounds and Si/Ge. A bottom cell bandgap of about 1 eV is desired for tandem operation.


Contact


180

Fig. 2: I-V-curve of planar coating system p-GaAs/AlOx/ZnO:AlFig. 1: a) GaAs nanowire covered with ZnO:Al; b) schematic structure of planar GaAs coated with TCO



181

Contact

Funding: FKZ 03SF0404A, BMBF, Carl-Zeiss-Stiftung

Photovoltaics Group


[1] A. Koch: Herstellung sowie Charakterisierung von ZnO:Al-Schichten in Anwendung auf III-V-Halbleiterstrukturen,

Masterarbeit, TU Ilmenau, 2014

[2] A. Nägelein: Herstellung und Charakterisierung von MOCVD-ALD-Al2O3 Schichten bezüglich ihrer Passivierungswirkung

auf Silizium, Masterarbeit, TU Ilmenau, 2014

[3] C� Koppka: MOCVD-growth and characterization of AZO-contacts for p-doped GaAs nanowire structures, Transparent

Conductive Oxides – Fundamentals and Applications 2014, Leipzig (29.09.14 - 02.10.14).

IntroductionHigh conversion efficiencies are one of the main objectives for photovoltaic devices. By using solar cells based on coaxial III-V-nanowire structures, it is possible to overcome the theoretical efficiency limit (Shockley-Queisser) for single absorber devices. The lower amount of used material due to the nanowire geometry and the operation under concentrated sunlight leads to a reduction in costs. The front side contacting of radial nanowire structures is one of the major challenges. For this purpose the use of ZnO:Al (AZO) seems promising. The most important properties of this TCO coating are a high transparency, an excellent conductivity and the ability to cover the nanowires completely.ExperimentalThe GaAs-nanowires were grown in an MOCVD reactor (AIX200) via gold-catalysed VLS (vapour liquid solid) method using GaP substrates.The AZO layers were produced by a new established cyclic MOCVD growth mode to provide a homogeneous, complete coverage of the surface, even with closely spaced nanowires (Fig. 1a) [1]. A thin AlOx layer was grown between the GaAs absorber and the AZO coating, which provides a diffusion barrier and improves the passivation [2]. Due to the difficulties of a sufficient characterization of thin ZnO:Al

layers on small free standing nanowire structures, most analyses were carried out on planar p-doped GaAs. The planar contact system (Fig. 1b) is comparable to the radial structure of the coated nanowires.The deposited films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) as well as different methods for determining the optical and electrical properties.ResultsSEM measurements reveal a homogeneous coating of the nanowire structures. The specific resistance of this AZO is in the range of 2*10-3 to 8*10-4 Ωcm. UV/VIS measurements show a transparency above 84% in the range from 400 to 800 nm. These properties are consistent with literature values and verify the suitability of ZnO:Al as a contact material. The structural analyses show interdependence between the crystal orientation and the growth temperature as well as the doping level. AES depth profiles reveal a homogeneous distribution of Al in ZnO and show the absence of As-diffusion. Current-voltage measurements reveal an ohmic behavior between TCO and III-V material (Fig. 2) and confirm the applicability of the contact system [3].

C. Koppka, A. Nägelein, A. Koch, T. Hannappel

ZnO:Al front contacting of III-V nanowire structures with radial configuration

Abd El-Maksoud, R. H.; Hillenbrand, M. and Sinzinger, S. Parabasal theory for plane-symmetric systems including freeform surfaces� Optical engineering. Bellingham, Wash Vol. 53(3), pp. 031303. SPIE. (2014)

Adam, G.; Yohannes, T.; White, M.; Montaigne, A.; Ulbricht, C.; Birckner, E.; Rathgeber, S.; Kästner, C.; Hoppe, H.; Sariciftci, N. S. and Ayuk Mbi Egbe, D. Effect of varying thiophene units on charge-transport and photovoltaic properties of poly(phenylene ethynylene)-alt-poly(phenylene vinylene) polymers� Macromolecular chemistry and physics. Weinheim Vol. 215(15), pp. 1473-1484. Wiley-VCH. (2014)

Ahmad, A.; Schuh, A. and Rangelow, I. W. Adaptive AFM scan speed control for high aspect ratio fast structure tracking� Review of Scientific Instruments 85, 103706. (2014)

Alassaad, K.; Soulière, V.; Cauwet, F.; Peyre, H.; Carole, D.; Kwasnicki, P.; Juillaguet, S.; Kups, T.; Pezoldt, J. and Ferro, G. Ge incorporation inside 4H-SiC during homoepitaxial growth by chemical vapor deposition� Acta materialia� Amsterdam [u�a�] Vol� 75, pp� 219-226� Elsevier Science. (2014)

Albrecht, R. and Lange, G. Pulvermetallurgisch hergestellte Aluminiumschäume� Lightweight design. Wiesbaden Vol. 7(6), pp. 26-31. Vieweg und Teubner/Springer Fachmedien. (2014)

Albrecht, R. and Lange, G. Faserverstärkte geschlossenporige Aluminiumschäume� Metall. Clausthal-Zellerfeld Vol. 68(9), pp. 355-359. GDMB-Informationsges. (2014)

Alferenok, A.; Pothérat, A. and Luedtke, U. Optimal magnet configurations for Lorentz force velocimetry in low conductivity fluids� Measurement Science and Technology 2465303 (13pp). (2013)

Alsharef, M. A.; Granzner, R. and Schwierz, F. Theoretical investigation of trigate AlGaN/GaN HEMTs� IEEE transactions on electron devices. New York, NY Vol. 60(10), pp. 3335-3341. IEEE. (2013)

Andrada, E.; Mämpel, J.; Schmidt, T.; Fischer, M. S.; Karguth, A. and Witte, H. From biomechanics of rats iInclined locomotion to a climbing robot� International Journal of Design & Nature and Ecodynamics 8(3) 191–212. (2013)

Andreev, O.; Kolesnikov, Y. and Thess, A. Visualization of the Ludford column� Journal of fluid mechanics. Cambridge [u.a.] Vol. 721, pp. 438-453. Cambridge Univ. Press. (2013)

Andreichenko, K.; Shelyuk, O.; Prylutska, S.; Nuryshchenko, N.; Bogutska, K.; Prylutskyy, Y.; Ritter, U. and Scharff, P. Effect of multi-walled iron-filled carbon nanotubes on ATPase activity and superprecipitation of natural actomyosin� Materialwissenschaft und Werkstofftechnik. Vol. 44(2/3), pp. 103-106. (2013)

Arines, J.; Hernandez, R. O.; Sinzinger, S.; Grewe, A. and Acosta, E. Wavefront-coding technique for inexpensive and robust retinal imaging� Optics letters. Washington, DC Vol. 39(13), pp. 3986-3988. Soc. (2014)

Augustin, S.; Fröhlich, T.; Ament, C.; Güther, T.; Irrgang, K. and Lippmann, L. Dynamic properties of contact thermometers for high temperatures� Measurement� Amsterdam [u�a�] Vol� 51, pp� 387-392� Elsevier Science. (2014)

Badea, C.; Pop, A.; Mattea, C.; Stapf, S. and Ardelean, I. The effect of curing temperature on early hydration of gray cement via fast field cycling-NMR relaxometry� Appl. Magn. Reson. 45, 1299-1309. (2014)

Barrigón, E.; Brückner, S.; Supplie, O.; Döscher, H.; Rey-Stolle, I. and Hannappel, T. In situ study of Ge(100) surfaces with tertiarybutylphosphine supply in vapor phase epitaxy ambient� Journal of Crystal Growth 35073. (2013)

Barrigón, E.; Brückner, S.; Supplie, O.; Kleinschmidt, P.; Rey-Stolle, I. and Hannappel, T. Optical in situ monitoring of hydrogen desorption from Ge(100) surfaces� Applied Physics Letters 10211608. (2013)

Beck, M.; Rousseau, J.; Klammer, M.; Leiderer, P.; Mittendorff, M.; Winnerl, S.; Helm, M.; Gol’tsman, G. N. and Demsar, J. Transient enhancement of superconductivity in a BCS superconductor driven by resonant narrowband terahertz excitation� Physical Review Letters. Vol. 110, pp. 267003. (2013)

Becker, F.; Zimmermann, K.; Volkova, T. and Minchenya, V. T. An amphibious vibration-driven microrobot with a piezoelectric actuator� Regular and chaotic dynamics. Moscow Vol. 18(1/2), pp. 63-74. Russian Academy of Sciences. (2013)

Beenken, W. J. D.; Herrmann, F.; Presselt, M.; Hoppe, H.; Shokhovets, S.; Gobsch, G. and Runge, E. Sub-bandgap absorption in organic solar cells: experiment and theory� Physical chemistry, chemical physics. Cambridge Vol. 15(39), pp. 16494-16502. RSC Publ. (2013)

Behn, C. Modeling the adjustment of receptor cells via adaptive [lambda]-stabilizing control� Journal of Mechatronics. Valencia, Calif Vol. 2(4), pp. 275-290. American Scientific Publishers. (2014)

Behn, C. Adaptive control of singularly perturbed worm-like locomotion systems� Differential equations and dynamical systems. New Delhi Vol. 21(1/2), pp. 59-69. Springer India. (2013)

Behn, C.; Schmitz, T.; Fremerey, M.; Voges, D.; Witte, H. and Zimmermann, K. Tasthaare für die Mechatronik - Modellbildung, Simulation und adaptive Regelung = Vibrissae in mechatronics - modeling, simulation and adaptive control� Fachtagung Mechatronik–12. (2013)

Bergmann, J. P.; Frisch, W. and Günther, K. Aufmischungsarmes, endkonturnahes Auftragschweißen hartstoffverstärkter Fe-Hartpanzerungen mittels geregelter, energiereduzierter MSG-Kurzlichtbogentechnik� Schweissen und Schneiden. Düsseldorf Vol. 65(9), pp. 602-607. DVS-Media GmbH. (2013)

Bergmann, J. P.; Petzoldt, F.; Schricker, K.; Günther, K. and Hübner, M. Prove di saldatura ad arco in short arc di leghe di magnesio e soluzioni per incentivare la riproducibilità del processo� Rivista italiana della saldatura. Milano Vol. 65(3), pp. 355-360. (2013)

Bergmann, J. P.; Petzoldt, F.; Schürer, R. and Schneider, S. Solid-state welding of aluminum to copper - case studies� Welding in the world. Heidelberg Vol. 57(4), pp. 541-550. Springer. (2013)

Biank, H. C.; Shokhovets, S.; Gobsch, G.; Runge, E.; Sensfuss, S.; Klemm, E. and Andrae, G. Optical Spectroscopy of photovoltaic systems based on low-bandgap polymers� Thin Solid Films 560 77-81. (2014)

Scientific PublicationsJournal Articles

Contact


182

macronano@tu-ilmenau�de | www�macronano�de

SCIENTIFIC PUBLICATIONS


183



Boeck, T. and Krasnov, D. A mixing-length model for side layers of magnetohydrodynamic channel and duct flows with insulating walls� Physics of fluids. [S.l.] Vol. 26(2), pp. 025106. American Institute of Physics. (2014)

Boeck, T.; Zec, M. and Thess, A. Electromagnetic drag on a magnetic dipole caused by a translating and rotating conducting cylinder� Journal of engineering mathematics. Dordrecht [u.a.] Vol. 88(1), pp. 177-195. Springer Science + Business Media B.V. (2014)

Bolotnik, N.; Pivovarov, M.; Zeidis, I. and Zimmermann, K. The undulatory motion of a chain of particles in a resistive medium in the case of a smooth excitation mode� ZAMM. Berlin Vol. 93(12), pp. 895-913. Wiley-VCH. (2013)

Borrmann, T.; McFarlane, A. J.; Ritter, U. and Johnston, J. H. Rhodium catalysts build into the structure of a silicate support in the hydroformylation of alkenes� Central European journal of chemistry. Vol. 11(4), pp. 561-568. (2013)

Brandel, O.; Kunert, J.; May, T.; Ortlepp, T.; Toepfer, H. and Meyer, H.-G. Improved Operation Range of RSFQ-Controlled Current Steering Switches� IEEE Transactions on applied Superconductivity, 24 Nr� 4, 2500106. (2014)

Brauer, H.; Porzig, K.; Mengelkamp, J.; Carlstedt, M.; Ziolkowski, M. and Toepfer, H. Lorentz force eddy current testing: a novel NDE-technique� COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, 33 Nr� 6, S� 1965-1977� (2014)

Brückner, S.; Döscher, H.; Kleinschmidt, P.; Supplie, O.; Dobrich, A. and Hannappel, T. Verfahren zur Oberflächenpräparation von Si(100)-Substraten� EU patent application, no. 12008516.2 – 1362. (2013)

Brückner, S.; Kleinschmidt, P.; Supplie, O.; Döscher, H. and Hannappel, T. In situ control of step formation on Si(100) surfaces during MOVPE preparation for III-V-on-Si solar cells� Photovoltaic Specialists Conference (PVSC). , pp. 0886-0890. (2013)

Brückner, S.; Kleinschmidt, P.; Supplie, O.; Döscher, H. and Hannappel, T. Domain-sensitive in situ observation of layer-by-layer removal at Si(100) in H2 ambient� New Journal of Physics 1513049. (2013)

Buchelnikov, A. S.; Voronin, D. P.; Kostjukov, V. V.; Deryabina, T. A.; Khrapatiy, S. V.; Prylutskyy, Y. I.; Ritter, U. and Evstigneev, M. P. Complexation of aromatic drugs with single-walled carbon nanotubes� Journal of nanoparticle research. Vol. 16(7), pp. 2472. (2014)

Budden, M.; Schneider, S.; Groß, G. A.; Kielpinski, M.; Henkel, T.; Cahill, B. and Köhler, J. M. Microfluidic encoding: generation of arbitrary droplet sequences by electrical switching in microchannels� Sensors and actuators� Amsterdam [u�a�] Vol� 189, pp� 288-297� Elsevier Science. (2013)

Budden, M.; Schneider, S.; Groß, G. A.; Kielpinski, M.; Henkel, T. and Köhler, J. M. Splitting and switching of microfluidic segments in closed channels for chemical operations in the segment-on-demand technology� Chem. Eng. J. 227 166-173. (2013)

Bukharov, M. S.; Shtyrlin, V. G.; Mukhtarov, A. S.; Mamin, G. V.; Stapf, S.; Mattea, C.; Krutikov, A. A.; Il’in, A. N. and Serov, N. Y. Structural and dynamic characteristics of copper(II) amino acid complexes in solutions by combined EPR and NMR relaxation methods� Phys. Chem. Chem. Phys. 16, 9411-9421. (2014)

Bund, A. and Kubeil, C. Double layer effects at nanosized electrodes� Faraday Disc. 16464 339-348. (2013)

Burkhardt, F.; Eberlein, E.; Jäckel, S.; Sommerkorn, G. and Prieto-Cerdeira, R. MIMOSA - a dual approach to detailed land mobile satellite channel modeling� International journal of satellite communications and networking� New York, NY [u�a�] Vol. 32(4), pp. 309-328. Wiley. (2014)

Busko, T.; Dmytrenko, O.; Kulish, M.; Prylutskyy, Y.; Shokhovets, S.; Gobsch, G.; Vityuk, N.; Eremenko, A. and Tkach, V. Optical and photocatalytic properties of TiO 2 films modified with oxides and gold� Materialwissenschaft und Werkstofftechnik� Weinheim Vol� 44(2/3), pp. 119-123. Wiley-VCH. (2013)

Calderón Ortiz, L. K.; Würfel, H.; Täuscher, E.; Weiß, D.; Birckner, E.; Görls, H. and Beckert, R. From Liquid to Solid-State Fluorescence: Tricyclic Lactones Based on 4-Hydroxy-1,3-thiazoles� Synthesis6(01):126-134. Epub 04.11.2013. (2013)

Camargo, M. K.; Schmidt, U.; Grieseler, R.; Wilke, M. and Bund, A. Electrodeposition of Zn-TiO2 Dispersion Coatings: Study of Particle Incorporation in Chloride and Sulfate Baths� J. Electrochem. Soc. 161168-D175. (2014)

Cao, D. W.; Wang, Z. J.; Nasori; Wen, L. Y.; Mi, Y. and Lei, Y. Switchable Charge-Transfer in the Photoelectrochemical Energy-Conversion Process of Ferroelectric BiFeO3 Photoelectrodes� Angewandte Chemie International Edition, 126 11207-11211� (2014)

Cao, J.; Kürsten, D.; Krause, K.; Kothe, E.; Martin, K.; Roth, M. and Köhler, J. M. Application of micro-segmented flow for two-dimensional characterization of the combinatorial effect of zinc and copper ions on metal-tolerant Streptomyces strains� Applied microbiology and biotechnology. Berlin Vol. 97(20), pp. 8923-8930. Springer. (2013)

Cao, J.; Nagl, S.; Kothe, E. and Köhler, J. M. Oxygen sensor nanoparticles for monitoring bacterial growth and characterization of dose-response functions in microfluidic screenings� Microchim. Acta. (2014)

Carlstedt, M.; Porzig, K.; Uhlig, R. P.; Zec, M.; Ziolkowski, M. and Brauer, H. Application of Lorentz force eddy current testing and eddy current testing on moving nonmagnetic conductors� International Journal of Applied Electromagnetics and Mechanics, 45 S. 519-1526. (2014)

Cimalla, V.; Baeumler, M.; Kirste, L.; Prescher, M.; Christian, B.; Passow, T.; Benkhelifa, F.; Bernhardt, F.; Eichapfel, G.; Himmerlich, M.; Krischok, S. and Pezoldt, J. Densification of thin aluminum oxide films by thermal treatments� Materials sciences and applications. Irvine, Calif Vol. 5(8), pp. 628-638. Scientific Research Publ. Inc. (2014)

Crowther, L. J.; Porzig, K.; Hadimani, R. L.; Brauer, H. and Jiles, D. C. Realistically modeled transcranial magnetic stimulation coils for Lorentz force and stress calculations during MRI� IEEE transactions on magnetics. New York, NY Vol. 49(7), pp. 3426-3429. IEEE. (2013)

Eisenhardt, A.; Krischok, S. and Himmerlich, M. Surface states and electronic structure of polar and nonpolar InN - An in-situ photoelectron spectroscopy study� Appl. Phys. Lett. 102 231602. (2013)

Eisenhardt, A.; Reiß, S.; Krischok, S. and Himmerlich, M. Reduction of electron accumulation at InN(0001) surfaces via saturation of surface states by potassium and oxygen as donor- or acceptor-type adsorbates� J. Appl. Phys. 115 043716. (2014)

El Mofid, W.; Ivanov, S.; Konkin, A. and Bund, A. A high performance layered transition metal oxide cathode material obtained by simultaneous aluminum and iron cationic substitution� J. Power Sources 2614-422. (2014)

Endlich, M.; Gozdzik, S.; Néel, N.; Rosa, A. L. d.; Frauenheim, T.; Wehling, T. O. and Kröger, J. Phthalocyanine adsorption to graphene on Ir(111): evidence for decoupling from vibrational spectroscopy� The journal of chemical physics. Vol. 141(18), pp. 184308. (2014)

Endlich, M.; Miranda, H. P. C.; Molina-Sánchez, A.; Wirtz, L. and Kröger, J. Moiré-induced replica of graphene phonons on Ir(111)� Annalen der Physik. Vol. 526(9/10), pp. 372-380. (2014)

Endlich, M.; Molina-Sánchez, A.; Wirtz, L. and Kröger, J. Screening of electron-phonon coupling in graphene on Ir(111)� Phys. Rev. Vol. 88(20), pp. 205403. (2013)

Endrödy, C.; Mehner, H.; Grewe, A.; Sinzinger, S. and Hoffmann, M. Two-dimensional stepping drive for hyperspectral systems� Proceedings of the 25th Micromechanics Europe Workshop, Istanbul, Turkey. (2013)

Engert, S.; Wetzstein, O.; Hofherr, M.; Ilin, K.; Siegel, M.; Meyer, H.-G. and Töpfer, H. Mathematical analysis of multiplexing techniques for SNSPD arrays� IEEE transactions on applied superconductivity� New York, NY Vol. 23(3), pp. 2501005. Inst. (2013)

Engmann, S.; Singh, C. R.; Turkovic, V.; Hoppe, H. and Gobsch, G. Direct correlation of the organic solar cell device performance to the in-depth distribution of highly ordered polymer domains in polymer/fullerene films� Advanced energy materials. Weinheim Vol. 3(11), pp. 1463-1472. Wiley-VCH. (2013)

Engmann, S.; Turkovic, V.; Hoppe, H. and Gobsch, G. Revealing the active layer morphology within complete solar cell devices via spectroscopic ellipsometry� The journal of physical chemistry. Washington, DC Vol. 117(47), pp. 25205-25210. Soc. (2013)

Evstigneev, M. P.; Buchelnikov, A. S.; Voronin, D. P.; Rubin, Y. V.; Belous, L. F.; Prylutskyy, Y. I. and Ritter, U. Complexation of C 60 fullerene with aromatic drugs� ChemPhysChem. Vol. 14(3), pp. 568-578. (2013)

Fang, J.; Park, S.-C.; Schlag, L.; Stauden, T.; Pezoldt, J. and Jacobs, H. O. Localized collection of airborne analytes: a transport driven approach to improve the response time of existing gas sensor designs� Advanced functional materials. Weinheim Vol. 24(24), pp. 3706-3714. Wiley-VCH. (2014)

Fang, J.; Park, S.-C.; Schlag, L.; Stauden, T.; Pezoldt, J. and Jacobs, H. O. Active matrix-based collection of airborne analytes: an analyte recording chip providing exposure history and finger print� Advanced materials. Weinheim Vol. 26(45), pp. 7600-7607. Wiley-VCH. (2014)

Cu-Nguyen, P.-H.; Grewe, A.; Hillenbrand, M.; Sinzinger, S.; Seifert, A. and Zappe, H. Tunable hyperchromatic lens system for confocal hyperspectral sensing� Optics express. Washington, DC Vol. 21(23), pp. 27611-27621. Soc. (2013)

Degli-Esposti, V.; Fuschini, F.; Vitucci, E. M.; Barbiroli, M.; Zoli, M.; Tian, L.; Yin, X.; Dupleich, D. A.; Müller, R.; Schneider, C. and Thomä, R. S. Ray-tracing-based mm-wave beamforming assessment� IEEE access. New York, NY Vol. 2, pp. 1314-1325. IEEE. (2014)

Dibb, G. F. A.; Muth, M. A.; Kirchartz, T.; Engmann, S.; Hoppe, H.; Gobsch, G.; Thelakkat, M.; Blouin, N.; Tierney, S.; Carrasco-Orozco, M.; Durrant, J. R. and Nelson, J. Limits on the Fill Factor in Organic Photovoltaics: Distinguishing Nongeminate and Geminate Recombination Mechanisms� Sci Rep 3 2045-2322. (2013)

Didenko, G.; Prylutska, S.; Kichmarenko, Y.; Potebnya, G.; Prylutskyy, Y.; Slobodyanik, N.; Ritter, U. and Scharff, P. Evaluation of the antitumor immune response to C 60 fullerene� Materialwissenschaft und Werkstofftechnik. Vol. 44(2/3), pp. 124-128. (2013)

Diethold, C.; Kühnel, M.; Hilbrunner, F.; Fröhlich, T. and Manske, E. Determination of force to displacement curves using a nanopositioning system based on electromagnetic force compensated balances� Measurement� Amsterdam [u�a�] Vol� 51, pp� 343-348� Elsevier Science. (2014)

Dimroth, F.; Grave, M.; Beutel, P.; Fiedeler, U.; Karcher, C.; D., T. T. N.; Oliva, E.; Siefer, G.; Schachtner, M.; Wekkeli, A.; Bett, A. W.; Krause, R.; Piccin, M.; Planc, N.; Drazek, C.; Guiot, E.; Ghyselen, B.; Salvetat, T.; Tauzin, A.; Signamarcheix, T.; Dobrich, A.; Hannappel, T. and Schwarzburg, K. Wafer bonded four-junction GaInP/GaAs/GaInAsP/GaInAs concentrator solar cells with 44.7% efficiency� Prog. Photovolt: Res. Appl. (2014)

Dimroth, F.; Roesener, T.; Essig, S.; Weuffen, C.; Wekkeli, A.; Oliva, E.; Siefer, G.; Volz, K.; Hannappel, T.; Haussler, D.; Jäger, W. and Bett, A. W. Comparison of Direct Growth and Wafer Bonding for the Fabrication of GaInP/GaAs Dual-Junction Solar Cells on Silicon� IEEE JOURNAL OF PHOTOVOLTAICS 4, Issue: 220-625. (2014)

Eberle, C. and Ament, C. Identification of tissue differentiation rates in a mechanobiological model of fracture healing� Computer methods in biomechanics and biomedical engineering. London [u.a.] Vol. 17(7), pp. 704-713. Taylor & Francis. (2014)

Eberle, C.; Niessen, M.; Hemmings, B. A.; Tschopp, O. and Ament, C. Novel individual metabolic profile characterizes the protein kinase B-alpha (pkbα -/-) in vivo model� Archives of physiology and biochemistry. London [u.a.] Vol. 120(3), pp. 91-98. Informa Healthcare. (2014)

Eberle, C.; Palinski, W. and Ament, C. A novel mathematical model detecting early individual changes of insulin resistance� Diabetes technology and therapeutics. Larchmont, NY Vol. 15(10), pp. 870-880. Liebert. (2013)

Eberlein, E.; Burkhardt, F.; Sommerkorn, G.; Jäckel, S. and Prieto-Cerdeira, R. MIMOSA - analysis of the MIMO channel for LMS systems� Space communications. Amsterdam Vol. 22(2/4), pp. 145-158. Elsevier. (2013)

Eigenbrod, H. and Bergmann, J. P. Fräsprozesse durch überlagerte Bewegungen optimieren� VDI-Z integrierte Produktion. Düsseldorf Vol. 155(2), pp. 30-31. Springer-VDI-Verl. (2013)

Contact


184




185



Goj, B.; Dressler, L. and Hoffmann, M. Resonant probing system comprising a high accurate uniaxial nanoprobe and a new evaluation unit� Journal of micromechanics and microengineering� Bristol Vol� 23(9), pp. 095012. Inst. (2013)

Goj, B.; Dressler, L. and Hoffmann, M. Resonant Biaxial Nanoprobe Utilized for Non-Contact Surface Measurements� Sensors & Transducers Journal 157 no� 10, p� 392-399, ISSN 1726- 5479. (2013)

Götz, T.; Huonker, R.; Witte, O. W. and Haueisen, J. Thalamocortical impulse propagation and information transfer in EEG and MEG� Journal of Clinical Neurophysiology, 31(3):253-60, 2014. (2014)

Gramfort, A.; Strohmeier, D.; Haueisen, J.; Hämäläinen, M. S. and Kowalski, M. Time-Frequency Mixed-Norm Estimates: Sparse M/EEG imaging with non-stationary source activations� Neuroimage, 70:410–422,. (2013)

Granzner, R.; Polyakov, V. M.; Schippel, C. and Schwierz, F. Empirical model for the effective electron mobility in silicon nanowires� IEEE transactions on electron devices. New York, NY Vol. 61(11), pp. 3601-3607. IEEE. (2014)

Grechnev, G. E.; Desnenko, V. A.; Fedorchenko, A. V.; Panfilov, A. S.; Kolesnichenko, Y. A.; Khrapatiy, S. V.; Prylutskyy, Y. I.; Matzui, L. Y.; Ritter, U. and Scharff, P. Magnetic properties of N-doped multi-walled carbon nanotubes� Materialwissenschaft und Werkstofftechnik. Vol. 44(2/3), pp. 136-138. (2013)

Greiner-Petter, C.; Tan, A. S. and Sattel, T. A semi-active magnetorheological fluid mechanism with variable stiffness and damping� Smart materials and structures. Bristol Vol. 23(11), pp. 115008. IOP Publ. (2014)

Grewe, A. Opto-mechanical microsystems for hyperspectral imaging sensors� Microsystems technology in Germany� Berlin Vol� 2014, pp� 52-53. Trias Consult. (2014)

Grewe, A.; Endrödy, C.; Hillenbrand, M.; Cu-Nguyen, P.-H.; Seifert, A.; Hoffmann, M. and Sinzinger, S. Compact hyperchromatic imaging systems based on tunable optical microsystems� IEEE Xplore digital library. , pp. 129-130. (2014)

Grewe, A.; Hillenbrand, M.; Endrödy, C.; Hoffmann, M. and Sinzinger, S. Advanced phase plates for confocal hyperspectral imaging systems� Optics infobase. (2013)

Grewe, A.; Hillenbrand, M. and Sinzinger, S. Aberration analysis of optimized Alvarez-Lohmann lenses� Applied optics. Washington, DC Vol. 53(32), pp. 7498-7506. Optical Soc. of America. (2014)

Grewe, A.; Hillenbrand, M. and Sinzinger, S. Bildgebende hyperspektrale Sensorik unter Einsatz verstimmbarer Optiken� Photonik. Fellbach Vol. 45(1), pp. 38-41. AT-Fachverl. (2013)

Grewe, A.; Hillenbrand, M. and Sinzinger, S. Hyperspectral imaging sensor systems using tunable lenses� Photonik international� ; trade journal on optical technologies ; selected photonik articles republished in English ; best of. Stuttgart Vol. 8, pp. 2-5. AT-Fachverl. (2013)

Grieseler, R.; Au, I. S.; Kups, T. and Schaaf, P. Diffusion in thin bilayer films during rapid thermal annealing� Physica status solidi. Weinheim Vol. 211(11), pp. 2635-2644. Wiley-VCH. (2014)

Fatkullin, N.; Mattea, C. and Stapf, S. On the theory of double-quantum NMR in polymer systems: The second cumulant approximation for many spin I=½ systems� J. Chem. Phys. 139, 194905/1-6. (2013)

Fdez-Aballí Altamirano, C.; Moldenhauer, S.; González Bayón, J.; Verhelst, S. and De Paepe, M. A two control volume model for the Thermal Lag Engine� Energy conversion and management� Amsterdam [u�a�] Vol� 78, pp. 565-573. Elsevier Science. (2014)

Fiedler, P.; Haueisen, J.; Jannek, D.; Griebel, S.; Zentner, L.; Vaz, F. and Fonseca, C. Comparison of three types of dry electrodes for electroencephalography� Acta IMEKO, 3(3):33–37, 2014. (2014)

Finck, A. v.; Herffurth, T.; Schröder, S.; Duparré, A. and Sinzinger, S. Characterization of optical coatings using a multisource table-top scatterometer� Applied optics. Washington, DC Vol. 53(4), pp. 259-269. Optical Soc. of America. (2014)

Fischer, M.; Gropp, S.; Nowak, J.; Capraro, B.; Hoffmann, M. and Müller, J. RF-MEMS-Platform based on Silicon-Ceramic-Composite-Substrates� Proceedings IMAPS/ACerS 10th International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystems Technologies (CICMT 2014), Suita, Japan. (2014)

Fourie, C. J.; Wetzstein, O.; Kunert, J.; Töpfer, H. and Meyer, H.-G. Experimentally verified inductance extraction and parameter study for superconductive integrated circuit wires crossing ground plane holes� Superconductor science and technology. Bristol Vol. 26(1), pp. 015016. IOP Publ. (2013)

Frisch, W. and Bergmann, J. P. Erweiterung der Anwendungsgrenzen beim Fügen mit pulsmodulierbaren Laserstrahlquellen durch den synergetischen Einsatz von zeitlich vorgelagertem Plasmalichtbogen� Schweissen und Schneiden. Düsseldorf Vol. 66(10), pp. 594-598. DVS-Media GmbH. (2014)

Garcia Ariza, A. P.; Müller, R.; Wollenschläger, F.; Schulz, A.; Elkhouly, M.; Sun, Y.; Glisic, S.; Trautwein, U.; Stephan, R.; Müller, J.; Thomä, R. S. and Hein, M. A. 60 GHz ultrawideband polarimetric MIMO sensing for wireless multi-gigabit and radar� IEEE transactions on antennas and propagation� New York, NY Vol. 61(4), pp. 1631-1641. IEEE. (2013)

Gevorgyan, S. A.; Madsen, M. V.; Dam, H. F.; Jørgensen, M.; Fell, C. J.; Anderson, K. F.; Duck, B. C.; Mescheloff, A.; Katz, E. A.; Elschner, A.; Rösch, R.; Hoppe, H.; Hermenau, M.; Riede, M. and Krebs, F. C. Interlaboratory outdoor stability studies of flexible roll-to-roll coated organic photovoltaic modules: stability over 10,000 h� Solar energy materials & solar cells� Amsterdam Vol� 116, pp� 187-196. North Holland. (2013)

Ghoshal, S.; Mattea, C. and Stapf, S. Protein renaturation in the gelatin film formation process� Appl. Magn. Reson. 45, 145-154. (2014)

Goernig, M.; Liehr, M.; Richter, J.; Heyne, J.; Leder, U.; Figulla, H. R. and Haueisen, J. Detection of Myocardial Scars by Magnetic Field Imaging� Journal of Medical and Biological Engineering, 33(1):111-116, 2013. (2013)

Goj, B.; Dressler, L. and Hoffmann, M. Semi-contact measurements of three-dimensional surfaces utilizing a resonant uniaxial microprobe� Journal of Measurement Science and Technology 2564012� (2014)

Grieseler, R.; Hähnlein, B.; Stubenrauch, M.; Kups, T.; Wilke, M.; Hopfeld, M.; Pezoldt, J. and Schaaf, P. Nanostructured plasma etched, magnetron sputtered nanolaminar Cr 2 AlC MAX phase thin films� Applied surface science� Amsterdam Vol� 292, pp� 997-1001� Elsevier. (2014)

Grimm, M.; Allén, M.; Marttila, J.; Valkama, M. and Thomä, R. Joint mitigation of nonlinear RF and baseband distortions in wideband direct-conversion receivers� IEEE transactions on microwave theory and techniques. New York, NY Vol. 62(1), pp. 166-182. IEEE. (2014)

Gropp, S.; Fischer, M.; Dittrich, L.; Capraro, B.; Müller, J. and Hoffmann, M. Wetting behaviour of LTCC and glasses on nanostructured silicon surfaces during sintering� Proceedings IMAPS/ACerS 10th International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystems Technologies (CICMT 2014), Suita, Japan,. (2014)

Gropp, S.; Fischer, M. and Hoffmann, M. Wettability of silicon nanostructures by glass melts� Proceedings of 40th Micro and Nano Engineering (MNE 2014), Lausanne Switzerland. (2014)

Grote, F.; Kühnel, R.; Balducci, A. and Lei, Y. Template assisted fabrication of free-standing MnO2 nanowire and nanotube arrays and their application in supercapacitors� Applied Physics letters 10453904. (2014)

Grote, F. and Lei, Y. A complete three-dimensionally nanostructured asymmetric supercapacitor with high operating voltage window based on PPy and MnO2� Nano Energy 10(2014) 63-70. (2014)

Grote, F.; Wen, L. Y. and Lei, Y. Nano-engineering of three-dimensional core/shell nanotube arrays for high performance supercapacitors� Journal of Power Sources 2567-42. (2014)

Grynyuk, I.; Grebinyk, S.; Prylutska, S.; Mykhailova, A.; Franskevich, D.; Matyshevska, O.; Schütze, C. and Ritter, U. Photoexcited fullerene C 60 disturbs prooxidant-antioxidant balance in leukemic L1210 cells� Materialwissenschaft und Werkstofftechnik. Vol. 44(2/3), pp. 139-143. (2013)

Günther, K.; Bergmann, J. P. and Schülze, R. Hot wire assisted gas metal arc welding of Ni-TC hardfacings� Welding and cutting. Düsseldorf Vol. 12(6), pp. 382-387. DVS-Verl. (2013)

Gutzeit, N.; Müller, J.; Reinlein, C. and Gebhardt, S. Manufacturing and characterization of a deformable membrane with integrated temperature sensors and heating structures in low temperature co-fired ceramics� International journal of applied ceramic technology� Westerville, Ohio Vol. 10(3), pp. 435-442. Wiley-Blackwell. (2013)

Haber-Pohlmeier, S.; Stapf, S. and Pohlmeier, A. NMR fast field cycling relaxometry of unsaturated soils� Appl. Magn. Reson. 45, 1099-1115. (2014)

Hähnlein, B.; Händel, B.; Schwierz, F. and Pezoldt, J. Properties of Graphene Side Gate Transistors� Mater. Sci. Forum, 740-742028-1031. (2013)

Hähnlein, B.; Schaaf, P. and Pezoldt, J. Size effect of Young‘s modulus in AlN thin layers� Journal of applied physics. Melville, NY Vol. 116(12), pp. 124306. American Inst. of Physics. (2014)

Hähnlein, B.; Stubenrauch, M.; Michael, S. and Pezoldt, J. Mechanical properties and residual stress of thin 3C-Si(111) films determined using MEMS structures� Mater. Sci. Forum, 778-78044-448. (2014)

Halbedel, B.; Resagk, C.; Wegfraß, A.; Diethold, C.; Werner, M.; Hilbrunner, F. and Thess, A. A novel contactless flow rate measurement device for weakly conducting fluids based on Lorentz force velocimetry� Flow, turbulence and combustion. Dordrecht [u.a.] Vol. 92(1/2), pp. 361-369. Springer Science + Business Media B.V. (2014)

Händel, B.; Hähnlein, B.; Göckeritz, G.; Schwierz, F. and Pezoldt, J. Electrical gating and rectification in graphene three-terminal junctions� Appl. Surf. Sci. 2917-92. (2014)

Hanitsch, S.; Grohmann, S.; Berg, A.; Moje, J. and Hoffmann, M. Method for testing of hydrogel sensor coatings� Biomedizinische Technik. Vol. 59(1), pp. 31-33. (2014)

Hanitsch, S. and Hoffmann, M. Test environment for hydrogels as functional sensor window� Biomedizinische Technik. Vol. 58(1), pp. 693-694. (2013)

Hannappel, T.; May, M. M. and Lewerenz, H. J. Photoelectrochemical Water Splitting: Issues and Perspectives chapter Epitaxial III-V Thin Film Absorbers: Preparation, Efficient InP Photocathodes and Routes to High Efficiency Tandem Structures� Cambridge: Royal Society of Chemistry, Energy and Environment Series, ISBN 978-1-84973-647-3. (2013)

Harczos, T.; Chilian, A. and Husar, P. Making use of auditory models for better mimicking of normal hearing processes with cochlear implants: the SAM coding strategy� IEEE transactions on biomedical circuits and systems. New York, NY Vol. 7(4), pp. 414-425. IEEE. (2013)

Heidrich, N.; Knöbber, F.; Polyakov, V.; Cimalla, V.; Pletschen, W.; Sah, R. E.; Kirste, L.; Leopold, S.; Hampl, S.; Ambacher, O. and Lebedev, V. Corrugated piezoelectric membranes for energy harvesting from aperiodic vibrations� Sensors and actuators� Amsterdam [u�a�] Vol� 195, pp� 32-37� Elsevier. (2013)

Heinicke, C. Spatially resolved measurements in a liquid metal flow with Lorentz force velocimetry� Experiments in fluids. Berlin Vol. 54(6) Springer. (2013)

Heinicke, C. and Thess, A. Electromagnetic force on a magnetic dipole inside an annular pipe flow� Physics of fluids. [S.l.] Vol. 25(9), pp. 097102. American Institute of Physics. (2013)

Heinicke, C. and Wondrak, T. Spatial and temporal resolution of a local Lorentz force flowmeter� Measurement science and technology. Bristol Vol. 25(5), pp. 055302. IOP Publ. (2014)

Hentschel, M. and Röder, G. The mesoscopic X-ray edge problem: boundary effects enhance photoabsorption in quantum dots� The European physical journal. Berlin Vol. 87(1) Springer. (2014)

Hilbrunner, F.; Weis, H. and Fröhlich, T. Parameterization and optimisation of EMC balances based on the frequency response of the impedance� Measurement� Amsterdam [u�a�] Vol� 51, pp� 349-355� Elsevier Science. (2014)

Hillenbrand, M.; Grewe, A. and Sinzinger, S. Parallelized chromatic confocal systems enable efficient spectral information coding� SPIE newsroom. Bellingham, Wash Vol. 2013 (2013)

Hillenbrand, M.; Hoffmann, A.; Kelly, D. P. and Sinzinger, S. Fast nonparaxial scalar focal field calculations� Journal of the Optical Society of America� Washington, DC Vol� 31(6), pp. 1206-1214. Soc. (2014)

Contact


186




187



Hillenbrand, M.; Kelly, D. P. and Sinzinger, S. Numerical solution of nonparaxial scalar diffraction integrals for focused fields� Journal of the Optical Society of America� Washington, DC Vol� 31(8), pp. 1832-1841. Soc. (2014)

Hillenbrand, M.; Lorenz, L.; Kleindienst, R.; Grewe, A. and Sinzinger, S. Spectrally multiplexed chromatic confocal multipoint sensing� Optics letters. Washington, DC Vol. 38(22), pp. 4694-4697. Soc. (2013)

Hillenbrand, M.; Mitschunas, B.; Brill, F.; Grewe, A. and Sinzinger, S. Spectral characteristics of chromatic confocal imaging systems� Applied optics. Washington, DC Vol. 53(32), pp. 7634-7642. Soc. (2014)

Hiller, L. and Pezoldt, J. AlGaN/GaN three-terminal junction devices for rectification and transistor applications on 3C-SiC/Si pseudosubstrates� IEEE transactions on electron devices. New York, NY Vol. 60(10), pp. 3047-3052. IEEE. (2013)

Hiller, L.; Stauden, T.; Kemper, R.; Lindner, J.; As, D. and Pezoldt, J. Hydrogen effects in ECR-etching of 3C-SiC(100) Mesa structures� Mater. Sci. Forum, 778-78030-733. (2014)

Hiller, L.; Tonisch, K. and Pezoldt, J. Side gate AlGaN/GaN FET on silicon and sapphire� Phys. Status Solidi C 1180-283. (2014)

Hiller, L.; Tonisch, K. and Pezoldt, J. SiC/Si speudosubstrates for AlGaN nanoelectronic devices� Mater. Sci. Forum, 740-742119-1122. (2013)

Himmerlich, M.; Eisenhardt, A.; Shokhovets, S.; Krischok, S.; Räthel, J.; Speiser, E.; Neumann, M. D.; Navarro-Quezada, A. and Esser, N. Confirmation of intrinsic electron gap states at nonpolar GaN(1-100) surfaces combining photoelectron and surface optical spectroscopy� Applied physics letters. Melville, NY Vol. 104(17), pp. 171602. American Inst. of Physics. (2014)

Himmerlich, M.; Knübel, A.; Aidam, R.; Kirste, L.; Eisenhardt, A.; Krischok, S.; Pezoldt, J.; Schley, P.; Sakalauskas, E.; Goldhahn, R.; Félix, R.; Mánuel, J. M.; Morales, F. M.; Carvalho, D.; Ben, T.; García, R. and Koblmüller, G. N-type conductivity and properties of carbon-doped InN(0001) films grown by molecular beam epitaxy� Journal of applied physics. Melville, NY Vol. 113(3), pp. 033501. American Inst. of Physics. (2013)

Himmerlich, M.; Lymperakis, L.; Gutt, R.; Lorenz, P.; Neugebauer, J. and Krischok, S. GaN(0001) surface states: Experimental and theoretical fingerprints to identify surface reconstructions� Phys. Rev. B 88 125304. (2013)

Hoffmann, M.; Müller, L.; Käpplinger, I.; Biermann, S. and Brode, W. Highly efficient IR-emitters based on oriented nanostructures on silicon templates� Proceedings of 40th Micro and Nano Engineering (MNE 2014), Lausanne Switzerland. (2014)

Höfft, O. and Krischok, S. Vacuum Electrochemistry in Ionic Liquids� The Electrochemical Society Interface 23 53. (2014)

Hohendorff, B.; Weidermann, C.; Pollinger, P.; Burkhart, K. J. and Müller, L. P. Jamming of fingers: an experimental study to determine force and deflection in participants and human cadaver specimens for development of a new bionic test device for validation of power-operated motor vehicle side door windows� Biomedizinische Technik. Berlin [u.a.] Vol. 58(1), pp. 39-49. de Gruyter. (2013)

Holle, W. and Husung, S. MTM im CAD-System - Produktbewertung nach Zeit und Kosten� Betriebspraxis & Arbeitsforschung. Heidelberg Vol. 221, pp. 36-41. Haefner-Verl. GmbH. (2014)

Hopfeld, M.; Grieseler, R.; Kups, T.; Wilke, M. and Schaaf, P. Thin film synthesis of Ti 3 SiC 2 by rapid thermal processing of magnetron-sputtered Ti[BOND]C[BOND]Si multilayer systems� Advanced engineering materials. Weinheim Vol. 15(4), pp. 269-275. Wiley-VCH Verl. (2013)

Hopfeld, M.; Grieseler, R.; Vogel, A.; Romanus, h. and Schaaf, P. Tribological behavior of selected M n+1 AX n phase thin films on silicon substrates� Surface and coatings technology� Amsterdam [u�a�] Vol� 257, pp� 286-294. Elsevier Science. (2014)

Huber, T.; Mariager, S. O.; Ferrer, A.; Schäfer, H.; Johnson, J. A.; Grübel, S.; Lübcke, A.; Huber, L.; Kubacka, T.; Dornes, C.; Laulhe, C.; Ravy, S.; Ingold, G.; Beaud, P.; Demsar, J. and Johnson, S. L. Coherent structural dynamics of a prototypical charge-density-wave-to-metal phase transition� Physical Review Letters. Vol. 113, pp. 26401. (2014)

Hunold, A.; Haueisen, J.; Ahtam, B.; Doshi, C.; Harini, C.; Camposano, S.; Warfield, S. K.; Grant, P. E. and Okada Y., P. C. Localization of the epileptogenic foci in tuberous sclerosis complex: a pediatric case report� Frontiers in Human Neuroscience, 8:175,. (2014)

Ishchuk, V.; Volland, B. E. and Rangelow, I. W. ViPER: simulation software for high aspect ratio plasma etching of silicon� Microsystem technologies. Berlin Vol. 20(10/11), pp. 1791-1796. Springer. (2014)

Ispas, A.; Gong, X.; Schneider, C.; Ascheid, G. and Thomä, R. Dual-polarized Ricean MIMO channels: modeling and performance assessment� IEEE transactions on communications. New York, NY Vol. 61(10), pp. 4218-4231. IEEE. (2013)

Ivanov, S.; Grieseler, R.; Cheng, L.; Schaaf, P. and Bund, A. Electrochemical lithiation of Si modified TiO2 nanotube arrays, investigated in ionic liquid electrolyte� J. Electroanal. Chem. 731-13. (2014)

Ivanov, S.; Tsakova, V. and Bund, A. Formation and electroanalytical performance of polyaniline-palladium nanocomposites obtained via Layer-by-Layer adsorption and electroless metal deposition� Electrochim. Acta 9057-165. (2013)

Ivanov, V.; Shyrokau, B.; Savitski, D.; Orus, J.; Meneses, R.; Rodríguez-Fortún, J.-M.; Theunissen, J. and Janssen, K. Design and testing of ABS for electric vehicles with individually controlled on-board motor drives� SAE International journal of passenger cars� Warrendale, Pa Vol� 7(2), pp. 902-913. Soc. (2014)

Jatal, W.; Tonisch, K.; Baumann, U.; Schwierz, F. and Pezoldt, J. AlGaN/GaN based HEMTs on SiC/Si-substrates: Influences on high frequency performance� Mater. Sci. Forum, 740-742115-1118. (2013)

Jiang, B.; Yang, Y.; Du, L. J.; Mattea, C.; Wang, J. D.; Stapf, S. and Yang, Y. R. Solvent diffusion in silica/poly[styrene-co-(acrylic acid)] core-shell microspheres by pulsed field gradient NMR techniques� J. Appl. Poly. Sci. 131, 40161. (2014)

Jiang, B.; Yang, Y.; Du, L. J.; Wang, J. D.; Yang, Y. R. and Stapf, S. Advanced catalyst technology for broad/bimodal polyethylene, achieved by polymer-coated particles supporting hybrid catalyst� Ind. Eng. Chem. Res. 52, 2501-2509. (2013)

Jurovata, D.; Kurnatova, J.; Ley, S.; Laqua, D.; Vazan, P. and Husar, P. Simulation of photon propagation in tissue using Matlab� Vedecké práce Materiálovotechnologickej Fakulty Slovenskej Technickej Univerzity v Bratislave so sídlom v Trnave� Warsaw Vol� 21, pp� 31-37. Versita. (2013)

Kaestner, M.; Hofer and I.W. Rangelow, M. Nanolithography by scanning probes on calixarene molecular glass resist using mix-and-match lithography� J. Micro/Nanolith. MEMS MOEMS Vol. 12(3), 031111-1 - 031111-13 (Jul-Sep 2013). (2013)

Kampmann, R.; Chall, A. K.; Kleindienst, R. and Sinzinger, S. Optical system for trapping particles in air� Applied optics. Washington, DC Vol. 53(4), pp. 777-784. Optical Soc. of America. (2014)

Karmo, D.; Ajib, S. and Al Khateeb, A. New method for designing an effective finned heat exchanger� Applied thermal engineering. Amsterdam [u.a.] Vol. 51(1/2), pp. 539-550. Elsevier Science. (2013)

Kästner, C.; Muhsin, B.; Wild, A.; Egbe, D. A. M.; Rathgeber, S. and Hoppe, H. Improved phase separation in polymer solar cells by solvent blending� J. Polymer Science Part B: Polymer Physics 51 868–874. (2013)

Kästner, C.; Rathgeber, S.; Egbe, D. A. M. and Hoppe, H. Improvement of photovoltaic performance by ternary blending of amorphous and semi-crystalline polymer analogues with PCBM� Journal of materials chemistry. Cambridge Vol. 1(12), pp. 3961-3969. Royal Soc. of Chemistry. (2013)

Kaufeld, M.; Lissek, F. and Bergmann, J. P. Aufs Abstützen kommt es an. Bearbeitungskriterien für die Zerspanung labiler CFK-Strukturen� Werkstatt + Betrieb. München Vol. 146(12), pp. 36-40. Hanser. (2013)

Kemper, R.; Hiller, L.; Stauden, T.; Pezoldt, J.; Duschik, K.; Niendorf, T.; Maier, H.; Meertens, D.; Tillmann, K.; As, D. and Lindner, J. Growth of cubic GaN on 3C-SiC/Si(001) nanostructures� J. Cryst. Growth 37891-294. (2013)

Kemper, R.; Mietze, C.; Hiller, L.; Stauden, T.; Pezoldt, J.; Meertens, D.; Luysberg, M.; As, D. and Lindner, J. Cubic GaN /AlN multi-quantum wells grown on pre-patterned 3C-SiC/Si(001)� Phys. Status Solidi C 1165-268. (2014)

Klapperstück, T.; Glanz, D.; Hanitsch, S.; Klapperstück, M.; Markwardt, F. and Wohlrab, J. Calibration procedures for the quantitative determination of membrane potential in human cells using anionic dyes� Cytometry. Hoboken, NJ Vol. 83(7), pp. 612-626. Wiley-Liss. (2013)

Kleindienst, R.; Becker, P.; Cimalla, V.; Grewe, A.; Hille, P.; Krüger, M.; Schörmann, J.; Schwarz, U. T.; Teubert, J.; Eickhoff, M. and Sinzinger, S. Integration of an opto-chemical detector based on group III-nitride nanowire heterostructures� Applied optics. Washington, DC Vol. 54(4), pp. 839-847. Soc. (2014)

Kleindienst, R.; Kampmann, R.; Stoebenau, S. and Sinzinger, S. Integriertes Design und Fertigung optischer Bauelemente� Herstellung eines hybriden diffraktiv-reflektiven optischen Strahlformers� Optik & Photonik. Weinheim Vol. 8(2), pp. 48-51. Wiley-VCH. (2013)

Klemm, M.; Dietzel, A.; Haueisen, J.; Nagel, E.; Hammer, M. and Schweitzer, D. Repeatability of autofluorescence lifetime imaging at the human fundus in healthy volunteers� Current Eye Research, 38(7):793-801, 2013. (2013)

Kletzin, U. and Reich, R. Schädigungsparameter bei der Lebensdauerabschätzung von Schraubendruckfedern� Konstruktion. Düsseldorf Vol. 65(5), pp. 59-60, 66. Springer-VDI-Verl. (2013)

Klumbies, H.; Karl, M.; Hermenau, M.; Rösch, R.; Seeland, M.; Hoppe, H.; Müller-Meskamp, L. and Leo, K. Water ingress into and climate dependent lifetime of organic photovoltaic cells investigated by calcium corrosion tests� Solar energy materials & solar cells. Amsterdam Vol. 120(2), pp. 685-690. North Holland. (2014)

Knauer, A.; Eisenhardt, A.; Krischok, S. and Köhler, J. M. Nanometer precise adjustment pf the silver shell thickness during automated Au-Ag core-shell nanoparticle synthesis in micro fluid segment sequences� Nanoscale 6 5230-5238. (2014)

Knauer, A. and Köhler, J. M. Screening of nanoparticle properties in microfluidic syntheses� Nanotechnol. Rev. 3 5-26. (2014)

Knauer, A. and Köhler, J. M. Screening of multiparameter spaces for silver nanoprism synthesis by microsegmented flow technique� Chemie - Ingenieur - Technik. Weinheim Vol. 85(4), pp. 467-475. Wiley-VCH Verl. (2013)

Knauer, A.; Visaveliya, N. and Köhler, J. M. Spontaneous transformation of polyelectrolyte-stabilized silver nanoprisms by interaction with thiocyanate� Journal of colloid and interface science� Orlando, Fla Vol� 394, pp. 78-84. Elsevier. (2013)

Köhler and M., J. Microfluidic systems and microreactors for the synthesis of new types of nanomaterials and nanomaterials of particular high quality, Editorial� Nanotechnol. Rev. 3 1-3. (2014)

Köhler, J. M. The ecological time-scale violation by industrial society and the chemical challenges for transition to a sustainable global entropy export management� Green processing & synthesis. Berlin Vol. 3(1), pp. 33-45. De Gruyter. (2014)

Köhler, J. M. and Knauer, A. Controlling formation and assembling of nanoparticles by control of electrical charging, polarization, and electrochemical potential� Nanotechnol. Rev. (3) (2014), 553-568. (2014)

Köhler, J. M.; Kraus, I.; Färber, J. and Serra, C. Continuous-flow preparation of nanoporous metal/polymer composite particles by in situ synthesis of silver nanoparticles in photopolymerized acrylate/diethylene glycol droplets� Journal of materials science. Dordrecht [u.a.] Vol. 48(5), pp. 2158-2166. Springer Science + Business Media B.V. (2013)

Köhler, J. M.; März, A.; Popp, J.; Knauer, A.; Kraus, I.; Faerber, J. and Serra, C. Polyacrylamid/Silver composit particles produced via microfluidic photopolymerization for single particle-based SERS microsensorics� Analytical Chem. 85 313-318. (2013)

Köhler, M.; Li, S. and Knauer, A. Why is micro segmented flow particularly promising for the synthesis of nanomaterials?� Chemical engineering & technology. Weinheim Vol. 36(6), pp. 887-899. Wiley-VCH Verl.-Ges. (2013)

Contact


188




189



Köhring, S. and Becker, F. Das rollende Bein - eine Kombination aus Rollen und Schreiten für die Nahfeldmobilität� Konstruktion. Düsseldorf Vol. 65(9), pp. 88-90. Springer-VDI-Verl. (2013)

Köhring, S.; Lutherdt, S.; Michaelis, A.; Becker, F.; Brandl, M.; Faenger, B.; Holder, S.; Fremerey, M.; Lawin, M.; Fränzel, N.; Weichert, F. and Witte, H. Nahfeldmobilität – der Schlüssel zu einem selbstbestimmten Leben im Alter� mobilogisch! Zeitschrift für Ökologie, Politik & Bewegung 11 1-5. (2014)

Köllner, T.; Schwarzenberger, K.; Eckert, K. and Boeck, T. Multiscale structures in solutal Marangoni convection: three-dimensional simulations and supporting experiments� Physics of fluids. [S.l.] Vol. 25(9), pp. 092109. American Institute of Physics. (2013)

Konkin, A.; Ritter, U.; Scharff, P.; Mamin, G.; Aganov, A.; Orlinskii, S.; Krinichnyi, V.; Egbe, D. A. M.; Ecke, G. and Romanus, H. Multifrequency X,W-band ESR study on photo-induced ion radical formation in solid films of mono- and di-fullerenes embedded in conjugated polymers� Carbon. Amsterdam [u.a.] Vol. 77, pp. 11-17. Elsevier Science. (2014)

Konkin, A.; Ritter, U.; Scharff, P.; Schrödner, M.; Sensfuss, S.; Aganov, A.; Klochkov, V. and Ecke, G. Improvement of P3HT-ICBA solar cell photovoltaic characteristics due to the incorporation of the maleic anhydride additive: P3HT morphology study of P3HT-ICBA and P3HT-ICBA-MA films by means of X-band LESR� Synthetic metals� Amsterdam [u�a�] Vol� 197, pp� 210-216� Elsevier Science. (2014)

Körner, M.; Schulz, M.; Fritze, H. and Stenzel, C. Control of partial pressure of oxygen in the ppm range based on a two metal-oxide buffer system� Sensors and actuators� Amsterdam [u�a�] Vol� 190, pp� 702-706� Elsevier Science. (2014)

Körner, M.; Shishkina, O.; Wagner, C. and Thess, A. Properties of large-scale flow structures in an isothermal ventilated room� Building and environment� New York, NY [u�a�] Vol� 59, pp� 563-574. Elsevier. (2013)

Korolovych, V. F.; Bulavin, L. A.; Prylutskyy, Y. I.; Khrapatiy, S. V.; Tsierkezos, N. G. and Ritter, U. Influence of Single-Walled Carbon Nanotubes on Thermal Expansion of Water� International Journal of Thermophysics.5(1):19-31. (2014)

Korolovych, V. F.; Nedyak, S. P.; Morou, K. O.; Prylutskyy, Y. I.; Scharff, P. and Ritter, U. Compressibility of water containing single-walled carbon nanotubes� Fullerenes, nanotubes & carbon nanostructures. Vol. 21(1), pp. 24-30. (2013)

Korte, S.; Steidl, M.; Prost, W.; Cherepanov, V.; Voigtländer, B.; Zhao, W.; Kleinschmidt, P. and Hannappel, T. Resistance and Dopant Profiling along Freestanding GaAs Nanowires� Appl. Phys. Lett. 10343104. (2013)

Kotik, D. and Hentschel, M. How curvature affects the far-field emission from deformed optical microcavities� Journal of optics. Bristol Vol. 15(1), pp. 014010. IOP Publ. (2013)

Krasnov, D.; Thess, A.; Boeck, T.; Zhao, Y. and Zikanov, O. Patterned turbulence in liquid metal flow: computational reconstruction of the Hartmann experiment� Physical review letters. Ridge, NY Vol. 110(8), pp. 084501. American Physical Society. (2013)

Krischok, S.; Ulbrich, A.; Ikari, T.; Kempter, V.; Marschewski, M. and Höfft, O. Surface structure of [XMIm] Tf2N ultrathin ionic liquid films probed by metastable He atoms and photoelectron spectroscopies (UPS and XPS)� Nucl. Instrum. Meth. B 340 51. (2014)

Kühnel, M.; Hilbrunner, F.; Büchner, H.-J.; Jäger, G.; Manske, E. and Fröhlich, T. Traceable measurement of mechanical parameters of double bending beam force transducers according to EN ISO 376� Measurement� Amsterdam [u�a�] Vol� 51, pp� 336-342� Elsevier Science. (2014)

Kunert, J.; Brandel, O.; Linzen, S.; Wetzstein, O.; Töpfer, H.; Ortlepp, T. and Meyer, H.-G. Recent developments in superconductor digital electronics technology at FLUXONICS foundry� IEEE transactions on applied superconductivity� New York, NY Vol. 23(5), pp. 1101707. Inst. (2013)

Kürsten, D.; Kothe, E.; Wetzel, K.; Bermann, K. and Köhler, J. M. Micro-segmented flow and multisensor technology for microbial activity profiling� Environmental Sci.: Process Impacts 16 2362-2370. (2014)

Kwon, T.-Y.; Lee, S.-Y.; Ryu, J.-W. and Hentschel, M. Phase-space analysis of lasing modes in a chaotic microcavity� Physical review. College Park, Md Vol. 88(2), pp. 023855. APS. (2013)

Lau, S.; Flemming, F. and Haueisen, J. Magnetoencephalography signals are influenced by skull defects� Clinical Neurophysiology, 125:1653–1662,. (2014)

Lauer, K.; Möller, C.; Schulze, D.; Bartel, T. and Kirscht, F. Calibration of excitonic photoluminescence to determine high aluminum concentrations in silicon� Physica status solidi. Weinheim Vol. 7(4), pp. 265-267. Wiley-VCH. (2013)

Leistritz, B. and Töpfer, H. Nonlinear vibration energy generators with mechanical stops for low-frequency broadband applications� Journal of physics. Bristol Vol. 476(1), pp. 012050. IOP Publ. (2013)

Lemme, M. C.; Li, L.-J.; Palacios, T. and Schwierz, F. Two-dimensional materials for electronic applications� MRS bulletin. Warrendale, Pa Vol. 39(8), pp. 711-718. MRS. (2014)

Leopold, S.; Müller, L.; Kremin, C. and Hoffmann, M. Online monitoring of the passivation breakthrough during deep reactive ion etching of silicon using optical plasma emission spectroscopy� Journal of micromechanics and microengineering. Vol. 23(7), pp. 074001. (2013)

Leopold, S.; Pätz, D.; Sinzinger, S.; Müller, J. and Hoffmann, M. Hybride Integration von Silicium- und LTCC Technologie zur Herstellung verstimmbarer Zylinderlinsen� Mikro-Nano-Integration : Beiträge des 5. GMM-Workshops,Ilmenau. - Berlin : VDE-Verl. (2014)

Leopold, S.; Polster, T.; Pätz, D.; Knöbber, F.; Ambacher, O.; Sinzinger, S. and Hoffmann, M. MOEMS tunable microlens made of aluminum nitride membranes� Journal of micro/nanolithography, MEMS and MOEMS� Bellingham, Wash Vol. 12(2), pp. 023012. Spie. (2013)

Li, S.; Knauer, A.; Risch, K.; Ritter, U. and Köhler, J. M. Synthesis and characterization of ZnO/4-mercaptobenzoic acid/Au composite particles� Materials letters� New York, NY [u�a�] Vol� 91, pp� 103-106� Elsevier. (2013)

Liang, L. Y.; Xu, Y.; Lei, Y. and Liu, H. M. 1-dimensional AgVO3 nanowires hybrid with 2-dimensional graphene nanosheets to create 3-dimensional composite aerogels and its improved electrochemical property� Nanoscale 6536-3539. (2014)

Liebl, M.; Steinhoff, U.; Wiekhorst, F.; Haueisen, J. and Trahms, L. Quantitative imaging of magnetic nanoparticles by magnetorelaxometry with multiple excitation coils� Physics in Medicine and Biology, 59(21):6607-20. (2014)

Lin, E.-C.; Fang, J.; Park, S.-C.; Johnson, F. W. and Jacobs, H. O. Effective localized collection and identification of airborne species through electrodynamic precipitation and SERS-based detection� Nature Communications. London Vol. 4 Nature Publishing Group. (2013)

Lin, E.-C.; Fang, J.; Park, S.-C.; Stauden, T.; Pezoldt, J. and Jacobs, H. O. Effective collection and detection of airborne species using SERS-based detection and localized electrodynamic precipitation� Advanced materials. Weinheim Vol. 25(26), pp. 3554-3559. Wiley-VCH. (2013)

Lubov, M.; Pezoldt, J. and Trushin, Y. Kinetic Monte Carlo simulation of impurity effects on nucleation and growth of SiC clusters on Si(100)� Mater. Sci. Forum, 740-74293-396. (2013)

Lüdtke, U. Numerische Simulation gekoppelter Felder in der Elektroprozesstechnik� Habilitation, Fakultät für Elektrotechnik und Informationstechnik, Technische Universität Ilmenau. (2014)

Luedtke, U.; Soubeih, S. and Halbedel, B. Using numerical simulation to optimize the external magnet system needed to improve the residence time distribution of glass melting tanks� Proceedings of the International Scientific Colloquium Modelling for Electromagnetic Processing MEP, Hannover� , pp� 177-182� (2014)

Luedtke, U.; Soubeih, S. and Halbedel, B. Numerical simulation of electromagnetically controlled flow in glass melting tanks� Proceedings of the International Conference on Heating by Electromagnetic Sources HES-13, Padova. , pp. 45-52. (2013)

Lux, R.; Kletzin, U.; Geinitz, V. and Beyer, P. Changes in mechanical parameters of stored patented cold-drawn steel wire� Wire journal international� Guildford, Conn� Vol� 47, pp� 78-83� (2014)

Lux, R.; Kletzin, U.; Geinitz, V. and Beyer, P. Langzeitstabilität von Draht� Draht. Bamberg Vol. 64(9), pp. 22-23. Meisenbach. (2013)

Madsen, M. V.; Gevorgyan, S. A.; Pacios, R.; Ajuria, J.; Etxebarria, I.; Kettle, J.; Bristow, N. D.; Neophytou, M.; Choulis, S. A.; Roman, L. S.; Yohannes, T.; Cester, A.; Cheng, P.; Zhan, X. W.; Wu, J.; Xie, Z. Y.; Tu, W. C.; He, J. H.; Fell, C. J.; Anderson, K.; Hermenau, M.; Bartesaghi, D.; Koster, L. J. A.; Machui, F.; Gonzalez-Valls, I.; Lira-Cantu, M.; Khlyabich, P. P.; Thompson, B. C.; Gupta, R.; Shanmugam, K.; Kulkarni, G. U.; Galagan, Y.; Urbina, A.; Abad, J.; Roesch, R.; Hoppe, H.; Morvillo, P.; Bobeico, E.; Panaitescu, E.; Menon, L.; Luo, Q.; Wu, Z. W.; Ma, C. Q.; Hambarian, A.; Melikyan, V.; Hambsch, M.; Burn, P. L.; Meredith, P.; Rath, T.; Dunst, S.; Trimmel, G.; Bardizza, G.; Mullejans, H.; Goryachev, A. E.; Misra, R. K.; Katz, E. A.; Takagi, K.; Magaino, S.; Saito, H.; Aoki, D.; Sommeling, P. M.; Kroon, J. M.; Vangerven, T.; Manca, J.; Kesters, J.; Maes, W.; Bobkova, O. D.; Trukhanov, V. A.; Paraschuk, D. Y.; Castro, F. A.; Blakesley, J.; Tuladhar, S. M.; Rohr, J. A.; Nelson, J.; Xia, J. B.; Parlak, E. A.; Tumay, T. A.; Egelhaaf, H. J.; Tanenbaum, D. M.; Ferguson, G. M.; Carpenter, R.; Chen, H. Z.; Zimmermann, B.; Hirsch, L.; Wantz, G.; Sun, Z. Q.; Singh, P.; Bapat, C.; Offermans, T. and Krebs, F. C. Worldwide outdoor round robin study of organic photovoltaic devices and modules� Solar Energy Materials and Solar Cells 130 281-290. (2014)

Mangold, H.; Bakulin, A. A.; Howard, I. A.; Kästner, C.; Egbe, D. A. M.; Hoppe, H. and Laquai, F. Control of charge generation and recombination in ternary polymer/polymer:fullerene photovoltaic blends using amorphous and semi-crystalline copolymers as donors� Physical chemistry, chemical physics. Cambridge Vol. 16(38), pp. 20329-20337. RSC Publ. (2014)

Markweg, E.; Hoffmann, M.; Schädel, M.; Ortlepp, H.-G. and Brodersen, O. A combined fibre coupling/readout diode chip for use in integrated optical interferometry� Tagungsband Smart Systems Integration, Wien, Austria. (2014)

Markweg, E.; Weinberger, S.; Nguyen, T. T.; Ament, C. and Hoffmann, M. Mikrolasertracker für die 3D Koordinatenmessung : kürzere Bearbeitungszeiten, höhere Messgenauigkeit� Optolines. (33), pp. 8-10. (2013)

Marton, M.; Vojs, M.; Zdravecká, E.; Himmerlich, M.; Haensel, T.; Krischok, S.; Kotlár, M.; Michniak, P.; Veselý, M. and Redhammer, R. Raman Spectroscopy of Amorphous Carbon prepared by Pulsed Arc Discharge in various Gas Mixtures� Journal of Spectroscopy 2013 467079. (2013)

Mattea, C.; Ghoshal, S.; Pabjanczyk, E. and Stapf, S. Poly(vinyl alcohol) film formation process using single-sided low-field NMR relaxometry: effect of initial concentration� Microporous Mesoporous Mater. 178, 27-30. (2013)

May, M. M.; Lewerenz, H. J. and Hannappel, T. Optical in Situ Study of InP(100) Surface Chemistry: Dissociative Adsorption of Water and Oxygen� J. Phys. Chem. C 118 (33) 19032-19041. (2014)

May, M. M.; Supplie, O.; Höhn, C.; van de Krol, R.; Lewerenz, H. J. and Hannappel, T. The interface of GaP(100) and H2O studied by photoemission and reflection anisotropy spectroscopy� New Journal of Physics 1503003. (2013)

May, M. M.; Supplie, O.; Höhn, C.; Zabka, W.-D.; Lewerenz, H. J.; van de Krol, R. and Hannappel, T. Water-induced modications of GaP(100) and InP(100)surfaces studied by photoelectron spectroscopy and reflection anisotropy spectroscopy� Solar Hydrogen and Nanotechnology VIII, edited by Yosuke Kanai, David Prendergast, Proc. of SPIE. Vol. 88220M-1 (2013)

Mehner, H.; Endrödy, C. and Hoffmann, M. Linear stepping microactuator for hyperspectral systems� IEEE Xplore digital library. , pp. 117-118. (2014)

Contact


190




191



Mehner, H.; Leopold, S. and Hoffmann, M. Variation of the intrinsic stress gradient in thin aluminum nitride films� Journal of micromechanics and microengineering� Bristol Vol� 23(9), pp. 095030. Inst. (2013)

Mehner, H.; Weise, C.; Schwebke, S.; Hampl, S. and Hoffmann, M. A passive microsystem for integrating acceleration loads� Proceedings of 40th Micro and Nano Engineering (MNE 2014), Lausanne Switzerland. (2014)

Messerschmidt, D.; Hochmuth, A.; Rädlein, E.; Romanus, H.; Gnehr, W.-M.; Eberhardt, J. and Ballif, C. Anodic degradation of ZnO on soda-lime glass� Solar energy materials & solar cells� Amsterdam Vol� 117, pp� 569-576. North Holland. (2013)

Mi, Y.; Zhou, M.; Wen, L. Y.; Zhao, H. P. and Lei, Y. High Efficient Visible-Light Driven Photocatalyst: Two Dimensional Square-like Bismuth Oxyiodine Nanosheets� Dalton Transactions 43549–9556. (2014)

Michael, M.; Streuel, P.; Witte, H.; Schilling, C. and Köhring, S. Das synthetische Faserseil in der Fördertechnik - vielversprechend und herausfordernd zugleich� Konstruktion. Düsseldorf Vol. 66(11/12), pp. 64-67. Springer-VDI-Verl. (2014)

Michels, T. and Rangelow, I. W. Review of scanning probe micromachining and its applications within nanoscience� Microelectronic Engineering p. 5. (2014)

Minchenko, D. O.; Prylutska, S. V.; Moenner, M.; Minchenko, O. H.; Prylutskyy, Y. I.; Schütze, C. and Ritter, U. Effect of C 60 fullerene on the expression of ERN1 signaling related genes in human astrocytes� Materialwissenschaft und Werkstofftechnik. Vol. 44(2/3), pp. 150-155. (2013)

Miyajima, S.; Ortlepp, T.; Töpfer, H.; Bozbey, A. and Fujimaki, A. Experimental demonstration and numerical analysis of microampere gray zone width with enhanced operating margin in shunted quasi-one junction superconducting quantum interference device comparators� Japanese journal of applied physics. Bristol Vol. 52(3), pp. 033101. IOP Publ. (2013)

Mohamad Salim, M. I.; Supriyanto, E.; Haueisen, J.; Ariffin, I.; Ahmad, A. H. and Rosidi, B. Measurement of bioelectric and acoustic profile of breast tissue using hybrid magnetoacoustic method for cancer detection� Medical & biological engineering & computing. Vol. 51(4), pp. 459-466. (2013)

Moldenhauer, S. Analytical model of the pulse tube engine� Energy� Amsterdam [u�a�] Vol� 62, pp� 285-299� Elsevier Science� (2013)

Moldenhauer, S.; Holtmann, C.; Stark, T. and Thess, A. Theoretical and experimental investigations of the pulse tube engine� Journal of thermophysics and heat transfer� Reston, Va Vol� 27(3), pp. 534-541. AIAA. (2013)

Moldenhauer, S.; Stark, T.; Holtmann, C. and Thess, A. The pulse tube engine: a numerical and experimental approach on its design, performance, and operating conditions� Energy� Amsterdam [u�a�] Vol� 55, pp� 703-715� Elsevier Science� (2013)

Mota, A. R.; Duarte, L.; Rodrigues, D.; Martins, A. C.; Machado, A. V.; Vaz, F.; Fiedler, P.; Haueisen, J.; Nóbrega, J. M. and Fonseca, C. Development of a quasi-dry electrode for EEG recording� Sensors and actuators. Vol. 199, pp. 310-317. (2013)

Muhsin, B.; Rösch, R.; Gobsch, G. and Hoppe, H. Flexible ITO-free polymer solar cells based on highly conductive PEDOT:PSS and a printed silver grid� Solar energy materials & solar cells� Amsterdam Vol� 130, pp� 551-554. North Holland. (2014)

Müller, J. Wide Band Measurement of Dielectric Properties of Electronic Assembly Materials Inside an LTCC Fluidic Structure� Journal of Microelectronics and Electronic Packaging1, p� 64-69� (2014)

Müller, L.; Käpplinger, I.; Biermann, S.; Brode, W. and Hoffmann, M. Infrared emitting nanostructures for highly efficient microhotplates� Journal of micromechanics and microengineering� Bristol Vol� 24(3), pp. 035014. Inst. (2014)

Müller, L.; Käpplinger, I.; Biermann, S.; Brode, W. and Hoffmann, M. Thermal infrared emitter featuring micro-nanostructures with high emission� Proceedings of the 24th Micromechanics Europe Workshop, Aalto, Finland. (2014)

Müller, L.; Käpplinger, I.; Brode, W. and Hoffmann, M. Funktionale Nanostrukturen für hocheffiziente Infrarotemitter in der Sensortechnik� Thüringer Werkstofftag – Jena. (2014)

Müller, M.; Klöckner, J.; Gushchina, I.; Pacholik, A.; Fengler, W. and Amthor, A. Performance evaluation of platform-specific implementations of numerically complex control designs for nano-positioning applications� International journal of embedded systems. Genève Vol. 5(1/2), pp. 95-105. Inderscience Publ. (2013)

Muncaci, S.; Mattea, C.; Stapf, S. and Ardelean, I. Frequency dependent NMR relaxation of liquids confined inside porous media containing an increased amount of magnetic impurities� Magn. Reson. Chem. 51, 123-128. (2013)

Munoz, A. G.; Heine, C.; Lublow, M.; Klemm, H. W.; Szabo, N.; Hannappel, T. and Lewerenz, H. J. Photoelectrochemical Conditioning of MOVPE p-InP Films for Light-Induced Hydrogen Evolution: Chemical, Electronic and Optical Properties� ECS Journal of Solid State Science and Technology 2(4) Q51-Q58. (2013)

Murtaza, N.; Sharma, R. K.; Thomä, R. S. and Hein, M. A. Directional antennas for cognitive radio: analysis and design recommendations� Progress in electromagnetics research. Cambridge, Mass Vol. 140, pp. 1-30. EMW. (2013)

Narandžić, M.; Schneider, C.; Kotterman, W. and Thomä, R. S. Quantification of scenario distance within generic WINNER channel model� International journal of antennas and propagation� New York, NY Vol. 2013 Hindawi. (2013)

Neudert, O.; Mattea, C.; Spieß, H. W.; Stapf, S. and Münnemann, K. Comparative study of 1H and 19F Overhauser DNP in fluorinated benzenes� Phys. Chem. Chem. Phys. 15, 20717-20726. (2013)

Neudert, O.; Raich, H.; Mattea, C.; Stapf, S. and Münnemann, K. An Alderman-Grant resonator for S-band dynamic nuclear polarization� J. Magn. Reson. 242, 79-85. (2014)

Niederschuh, S. J.; Witte, H. and Schmidt, M. The role of vibrissal sensing in forelimb position control during travelling locomotion in the rat (Rattus norvegicus, Rodentia)� Zoology (in press). Online: DOI: 10.1016/j.zool.2014.09.003. (2014)

Novotny, I.; Flickyngerova, S.; Tvarozek, V.; Sutta, P.; Netrvalova, M.; Roßberg, D. and Schaaf, P. Surface morphology and crystalline structure of sequentially sputtered ZnO nanocoatings� Applied surface science� Amsterdam Vol� 312, pp� 167-171� Elsevier. (2014)

Oliveira, R. S.; Winter, S.; Lepikson, H. A.; Fröhlich, T. and Theska, R. A new approach to test torque transducers under dynamic reference regimes� Measurement� Amsterdam [u�a�] Vol� 58, pp� 354-362� Elsevier Science. (2014)

Otto, T.; Rossi, M. and Boeck, T. Viscous instability of a sheared liquid-gas interface: dependence on fluid properties and basic velocity profile� Physics of fluids. Melville, NY Vol. 25(3), pp. 032103. AIP. (2013)

Ovsienko, I. V.; Matzui, L. Y.; Yatsenko, I. V.; Khrapatiy, S. V.; Prylutskyy, Y. I.; Ritter, U.; Scharff, P. and Le Normand, F. Magnetoresistance of multi-walled carbon nanotubes modified with iron� Materialwissenschaft und Werkstofftechnik. Vol. 44(2/3), pp. 161-166. (2013)

Pahl, C.; Zare, M.; Bin Ahmad, A.; Detschew, V.; Ammon, D.; Lehnert, S. and Supriyanto, E. Identification of quality parameters for an E-Health platform in the federal state of Thuringia in Germany� Journal of Soft Computing and Decision Support Systems� Johor Vol. 1(1), pp. 17-23. (2014)

Park, S.; Fang, J.; Biswas, S.; Mozafari, M.; Stauden, T. and Jacobs, H. A First Implementation of an Automated Reel-to-Reel Fluidic Self-Assembly Machine� Advanced Materials 26 (34) (2014), 5942-5949. (2014)

Park, S.; Fang, J.; Biswas, S.; Mozafari, M.; Stauden, T. and Jacobs, H. Self-Assembly: A First Implementation of an Automated Reel-to-Reel Fluidic Self-Assembly Machine (Adv. Mater. 34/2014)� Advanced Materials 26 (34) (2014), 5890-5890. (2014)

Park, S.-C.; Fang, J.; Biswas, S.; Mozafari, M.; Stauden, T. and Jacobs, H. O. A first implementation of an automated reel-to-reel fluidic self-assembly machine� Advanced materials. Weinheim Vol. 26(34), pp. 5942-5949. Wiley-VCH. (2014)

Pätz, D.; Deutschmann, T.; Oesterschulze, E. and Sinzinger, S. Depth of focus analysis of optical systems using tunable aperture stops with a moderate level of absorption� Applied optics. Washington, DC Vol. 53(28), pp. 6508-6512. Optical Soc. of America. (2014)

Pätz, D.; Leopold, S.; Hoffmann, M. and Sinzinger, S. Tunable anamorphotic imaging system based on fluidic cylindrical lenses� IEEE Xplore digital library. , pp. 25-26. (2014)

Pätz, D.; Sinzinger, S.; Leopold, S. and Hoffmann, M. Imaging systems with aspherically tunable micro-optical elements� Optics infobase. (2013)

Pedrosa, P.; Alves, E.; Barradas, N. P.; Martin, N.; Fiedler, P.; Haueisen, J.; Vaz, F. and Fonseca, C. Electrochemical behaviour of nanocomposite Ag x :TiN thin films for dry biopotential electrodes� Electrochim. Acta. Vol. 125, pp. 48-57. (2014)

Perets, Y. S.; Matzui, L. Y.; Vovchenko, L. L.; Prylutskyy, Y. I.; Scharff, P. and Ritter, U. The effect of boron nitride on electrical conductivity of nanocarbon-polymer composites� J. Mater. Sci. Vol. 49(5), pp. 2098-2105. (2014)

Petković, B.; Haueisen, J.; Zec, M.; Uhlig, R. P.; Brauer, H. and Ziolkowski, M. Lorentz force evaluation: a new approximation method for defect reconstruction� NDT & E international� Amsterdam [u�a�] Vol� 59, pp� 57-67� Elsevier Science. (2013)

Pezoldt, J.; Hähnlein, B.; Stubenrauch, M.; Tonisch, K.; Grieseler, R.; Vanco, L. and Schaaf, P. Verspannungsanalyse mit Raman-Spektroskopie an MEMS aus Gruppe III-Nitriden� S� 101 - 106, In: Thüringer Werkstofftag 2013 - Wissenschaftliche Beiträge, Schriftenreihe Werkstofftechnik Aktuell Bd. 9, Hrsg. P. Schaaf, E. Rädlein, Universitätsverlag Ilmenau, Ilmenau. (2013)

Piekarz, I.; Sorocki, J.; Wincza, K.; Gruszczynski, S.; Müller, J. and Welker, T. Miniaturized quasi-lumped coupled-line single-section directional coupler designed in multilayer LTCC technology� Microwave and optical technology letters� New York, NY [u�a�] Vol. 55(6), pp. 1401-1405. Wiley. (2013)

Podoskin, B.; Brueckner, K.; Blau, K.; Mehner, H.; Hoffmann, M. and Hein, M. A. Piezoelectric aluminum nitride MEMS resonators for RF oscillator integrated circuits� Proceedings of the 24th Micromechanics Europe Workshop, Aalto, Finland. (2013)

Porer, M.; Leierseder, U.; Ménard, J.-M.; Dachraoui, H.; Mouchliadis, L.; Perakis, I. E.; Heinzmann, U.; Demsar, J.; Rossnagel, K. and Huber, R. Non-thermal separation of electronic and structural orders in a persisting charge density wave� Nature Materials. Vol. 13, pp. 857-861. (2014)

Pothérat, A. and Klein, R. Why, how and when MHD turbulence at low Rm becomes three-dimensional� Journal of fluid mechanics. Cambridge [u.a.] Vol. 761, pp. 168-205. Cambridge Univ. Press. (2014)

Prylutska, S.; Bilyy, R.; Shkandina, T.; Rotko, D.; Bychko, A.; Cherepanov, V.; Stoika, R.; Rybalchenko, V.; Prylutskyy, Y.; Tsierkezos, N. and Ritter, U. Comparative study of membranotropic action of single- and multi-walled carbon nanotubes� J. Biosci. Bioeng. Vol. 115(6), pp. 674-679. (2013)

Prylutska, S. V.; Didenko, G. V.; Potebnya, G. P.; Bogutska, K. I.; Prylutskyy, Y. I.; Ritter, U. and Scharff, P. Toxic effect of C60 fullerene-doxorubicin complex towards tumor and normal cells in vitro� Biopolymers and cell. Vol. 30(5), pp. 372-376. (2014)

Prylutskyy, Y. I.; Buchelnikov, A. S.; Voronin, D. P.; Kostjukov, V. V.; Ritter, U.; Parkinson, J. A. and Evstigneev, M. P. C 60 fullerene aggregation in aqueous solution� Physical chemistry, chemical physics. Vol. 15(23), pp. 9351-9360. (2013)

Prylutskyy, Y. I.; Evstigneev, M. P.; Pashkova, I. S.; Wyrzykowski, D.; Woziwodzka, A.; Gołuński, G.; Piosik, J.; Cherepanov, V. V. and Ritter, U. Characterization of C 60 fullerene complexation with antibiotic doxorubicin� Physical chemistry, chemical physics. Vol. 16(42), pp. 23164-23172. (2014)

Prylutskyy, Y. I.; Petrenko, V. I.; Ivankov, O. I.; Kyzyma, O. A.; Bulavin, L. A.; Litsis, O. O.; Evstigneev, M. P.; Cherepanov, V. V.; Naumovets, A. G. and Ritter, U. On the origin of C 60 fullerene solubility in aqueous solution� Langmuir. Vol. 30(14), pp. 3967-3970. (2014)

du Puits, R.; Li, L.; Resagk, C.; Thess, A. and Willert, C. Turbulent boundary layer in high Rayleigh number convection in air� Physical review letters. College Park, Md Vol. 112(12), pp. 124301. APS. (2014)

Contact


192




193



du Puits, R.; Resagk, C. and Thess, A. Thermal boundary layers in turbulent Rayleigh-Bénard convection at aspect ratios between 1 and 9� New journal of physics� [Bad Honnef] Vol� 15, pp� 013040� Dt� Physikalische Ges. (2013)

Pulugundla, G.; Heinicke, C.; Karcher, C. and Thess, A. Lorentz force velocimetry with a small permanent magnet� European journal of mechanics� Paris Vol� 41, pp� 23-28� Gauthier-Villars. (2013)

Quiroz, P. and Halbedel, B. Kinetic study of crystallization titanium substituted barium hexaferrite in a glassy matrix of the system BaO-Fe 2 O 3 -TiO 2 -B 2 O 3� High temperatures, high pressures. Philadelphia, Pa Vol. 42(4), pp. 367-375. OCP Science. (2013)

Radchenko, N. V.; Prylutskyy, Y. I.; Shapoval, L. M.; Sagach, V. F.; Davydovska, T. L.; Dmitrenko, O. V.; Stepanenko, L. G.; Pobigailo, L. S.; Schütze, C. and Ritter, U. Impact of single-walled carbon nanotubes on the medullary neurons in spontaneously hypertensive rats� Materialwissenschaft und Werkstofftechnik. Vol. 44(2/3), pp. 171-175. (2013)

Ramon, C.; Garguilo, P.; Fridgeirsson, E. A. and Haueisen, J. Changes in scalp potentials and spatial smoothing effects of inclusion of dura layer in human head models for EEG simulations� Frontiers in neuroengineering. Vol. 7(32) (2014)

Rangelow, I.; Kästner, M.; Ivanov, T.; Hofer, M.; Ahmad, A.; Guliyev, E.; Angelov, T.; Reum, A.; Lenk, S.; Schuh, A.; Krivoshapkina, Y.; Budden, M.; Nieradka, K.; Zöllner, J.-P.; Nikolov; M. Holz, N.; be published in JVST, t. and B) Scanning Probes for Nanomanufacturing� The 58th international conference on electron, ion and photon beam technology & nanofabrication, Washington, DC, May 27 - May 30,. (2014)

Rangelow, I. W.; Sinzinger, S.; Steffanson, M.; Holz, M.; Ivanov, T.; Kleindienst, R. and Kampmann, R. Thermographischer Detektor basierend auf einem neuartigen Mikro-Spiegel Sensor� Technisches Messen. Berlin Vol. 81(5), pp. 219-227. De Gruyter. (2014)

Raue, M.; Bernet, A.; Küppers, M.; Stapf, S.; Schmidt, H.-W.; Blümich, B. and Mang, T. Sodium NMR relaxation – a versatile non-invasive tool for the monitoring of phase transitions and the estimation of effective pore sizes of supramolecular hydrogels� Prog. Colloid Polymer Sci. 140, 45-51. (2013)

Raue, M.; Martins, J.; Küppers, T.; Mang, T.; Blümich, B. and Stapf, S. Visualization of hydrogel shrinkage due to ion replacement by 27Al and 23Na magnetic resonance imaging� Prog. Colloid Polymer Sci. 140, 35-43. (2013)

Reich, R. and Kletzin, U. Tests für die Federauslegung� Draht. Bamberg Vol. 65(2), pp. 76-79. Meisenbach. (2014)

Reimann, T.; Töpfer, J.; Barth, S.; Bartsch, H. and Müller, J. Low-temperature sintered NTC thermistor ceramics for thick-film temperature sensors� International journal of applied ceramic technology� Westerville, Ohio Vol. 10(3), pp. 428-434. Wiley-Blackwell. (2013)

Reimund, V.; Pelkner, M.; Kreutzbruck, M. and Haueisen, J. Sensitivity analysis of the non-destructive evaluation of micro-cracks using GMR sensors� NDT & E international. Vol. 64, pp. 21-29. (2014)

Reiß, S.; Eisenhardt, A.; Krischok, S. and Himmerlich, M. Impact of potassium and water on the electronic properties of InN(0001) surfaces� Phys. Status Solidi C 11 428. (2014)

Ritter, U.; Prylutskyy, Y. I.; Evstigneev, M. P.; Davidenko, N. A.; Cherepanov, V. V.; Senenko, A. I.; Marchenko, O. A. and Naumovets, A. G. Structural Features of Highly Stable Reproducible C60 Fullerene Aqueous Colloid Solution Probed by Various Techniques� Fullerenes, Nanotubes and Carbon Nanostructures3(6):530-534. (2014)

Romanyuk, O.; Hannappel, T. and Grosse, F. Atomic and electronic structure of GaP/Si(111), GaP/Si(110), and GaP/Si(113) interfaces and superlattices studied by density functional theory� Physical Review B 8815312. (2013)

Rösch, R.; Eberhardt, K.-R.; Engmann, S.; Gobsch, G. and Hoppe, H. Polymer solar cells with enhanced lifetime by improved electrode stability and sealing� Solar energy materials & solar cells� Amsterdam [u�a�] Vol� 117, pp. 59-66. NH, Elsevier. (2013)

Rösch, R.; Seeland, M.; Bärenklau, M.; Gobsch, G. and Hoppe, H. Stability of polymer solar cells: dependence on working pressure� Solar energy materials & solar cells� Amsterdam [u�a�] Vol� 111, pp. 212-215. NH, Elsevier. (2013)

Rössler, E. A.; Stapf, S. and Fatkullin, N. Recent NMR investigations on molecular dynamics of polymer melts in bulk and in confinement� Curr. Opin. Colloid Interface Sci. 18, 173-182. (2013)

Rydosz, A.; Maziarz, W.; Pisarkiewicz, T.; Bartsch, H. and Müller, J. A Micropreconcentrator Design Using Low Temperature Cofired Ceramics Technology for Acetone Detection Applications� IEEE - Sensors Journal13 no. 5, p. 1889-1896. (2013)

Ryu, J.-W.; Lee, S.-Y.; Kim, I.; Choi, M.; Hentschel, M. and Kim, S. W. Abnormal high-Q modes of coupled stadium-shaped microcavities� Optics letters. Washington, DC Vol. 39(14), pp. 4196-4199. Soc. (2014)

Sachs, J.; Helbig, M.; Herrmann, R.; Kmec, M.; Schilling, K. and Zaikov, E. Remote vital sign detection for rescue, security, and medical care by ultra-wideband pseudo-noise radar� Ad hoc Networks. Amsterdam [u.a.] Vol. 13(1), pp. 42-53. Elsevier Science. (2014)

Sachse, T.; Néel, N.; Meierott, S.; Berndt, R.; Hofer, W. A. and Kröger, J. Electronic and magnetic states of Mn 2 and Mn 2 H on Ag(111)� New journal of physics. Vol. 16, pp. 063021. (2014)

Sadi, T. and Schwierz, F. Improved empirical non-linear compact model for studying intermodulation in HEMTs and LDMOSFETs� Solid state electronics� Oxford [u�a�] Vol� 81, pp� 91-100� Pergamon, Elsevier Science. (2013)

Saft, B.; Schäfer, E.; Jäger, A.; Hampl, S.; Leistritz, B. and Hennig, E. Eine Systemarchitektur für ein integriertes elektrostatisches MEMS-Energy-Harvesting-Modul� Proceedings ANALOG- 14� GMM/ITG-Fachtagung, Hannover� , pp. 60-65. (2014)

Sagalianov, I. Y.; Prylutskyy, Y. I.; Tatarenko, V. A.; Radchenko, T. M.; Sudakov, O. O.; Ritter, U.; Scharff, P. and Le Normand, F. Influence of impurity defects on vibrational and electronic structure of graphene� Materialwissenschaft und Werkstofftechnik. Vol. 44(2/3), pp. 183-187. (2013)

Samsami, F.; Kolesnikov, Y. and Thess, A. Vortex dynamics in the wake of a magnetic obstacle� Journal of visualization. Berlin Vol. 17(3), pp. 245-252. Springer. (2014)

Schaefer, H.; Kabanov, V. and Demsar, J. Collective modes in quasi-one-dimensional charge-density wave systems probed by femtosecond time-resolved optical studies� Physics: Physical Review B 89,45106. (2014)

Schalles, M. and Thewes, R. Comparison of thermal modeling approaches for complex measurement equipment� International Journal of Thermophysics Bd. 35, S. 225 – 237. (2014)

Scheinert, S.; Grobosch, M.; Sprogies, J.; Hörselmann, I.; Knupfer, M. and Paasch, G. Organic [6,6]-phenyl-C61-butyric-acid-methyl-ester field effect transistors: analysis of the contact properties by combined photoemission spectroscopy and electrical measurements� Journal of applied physics. Melville, NY Vol. 113(17), pp. 174504. American Inst. of Physics. (2013)

Scheinert, S. and Paasch, G. Influence of the carrier density in disordered organics with Gaussian density of states on organic field-effect transistors� Journal of applied physics. Melville, NY Vol. 115(4), pp. 044507. American Inst. of Physics. (2014)

Scheinert, S.; Zaki, T.; Rödel, R.; Hörselmann, I.; Klauk, H. and Burghartz, J. N. Numerical analysis of capacitance compact models for organic thin-film transistors� Organic electronics. Amsterdam [u.a.] Vol. 15(7), pp. 1503-1508. Elsevier Science. (2014)

Schilling, C. and Witte, H. Bionische Anregungen zur Gestaltung von Gelenkungen� Konstruktion. Düsseldorf Vol. 66(9), pp. 69-71. Springer-VDI-Verl. (2014)

Schmidt, T.; Gerhardt, U.; Kupper, C.; Manske, E. and Witte, H. A miniaturized laser-Doppler-system in the ear canal� SPIE BiOS 85651 85651N. (2013)

Schneider, R.; Haueisen, J. and Pfeuffer, J. Shaped saturation with inherent radiofrequency-power-efficient trajectory design in parallel transmission� Magnetic Resonance Medicine, Vol. 72(4), pp. 1015-1027. (2014)

Schramm, S.; Seifert, B.-U.; Schikowski, P.; Prehl, J.; Kunert, K. S.; Blum, M.; Kaeding, A. and Haueisen, J. A modified Hartmann-Shack aberrometer for measuring stray light in the anterior segment of the human eye� Graefe‘s Archive for Clinical and Experimental Ophthalmology� Vol. 251, pp. 1967–1977. (2013)

Schricker, K.; Stambke, M. and Bergmann, J. P. Experimental investigations and modeling of the melting layer in polymer-metal hybrid structures� Welding in the world. Heidelberg Vol. 2014 Springer. (2014)

Schulz, A.; Xia, L.; Mueller, J.; Rentsch, S. and Mueller, R. A low-loss fully embedded stripline parallel coupled BPF for applications using the 60 GHz band� International journal of applied ceramic technology� - Westerville, Ohio : Wiley-Blackwell� - Bd� 10�2013, 2, S� 307-312� (2013)

Schulz, S.; Tupaika, N.; Berger, S.; Haueisen, J.; Bär, K.-J. and Voss, A. Cardiovascular coupling analysis with high-resolution joint symbolic dynamics in patients suffering from acute schizophrenia� Physiological Measurement, Vol. 34(8), pp. 883-901. (2013)

Schütz, R.; Malhotra, S.; Thomas, I.; Strothkämper, C.; Bartelt, A.; Schwarzburg, K.; Hannappel, T.; Fasting, C. and Eichberger, R. Dynamics of a Covalently Conjoined FRET Dye Ensemble for Electron Injection into ZnO Nanorods� J. Phys. Chem. C. 118 (18) (2014) 9336–9345. (2014)

Schwarz, S. U.; Cimalla, V.; Eichapfel, G.; Himmerlich, M.; Krischok, S. and Ambacher, O. Thermal functionalization of GaN surfaces with 1-alkenes� Langmuir 29 6296. (2013)

Schwarzenberger, K.; Köllner, T.; Linde, H.; Odenbach, S.; Boeck, T. and Eckert, K. On the transition from cellular to wavelike patterns during solutal Marangoni convection� European physical journal special topics. Berlin Vol. 219(1), pp. 121-130. Springer. (2013)

Schwarzer, S.; Augsburg, K.; Körner, T. and Bruckner, J. Hohlradgetriebene Innenzahnradpumpen - Antriebskonzept, Konstruktion und Versuche� Konstruktion. Düsseldorf Vol. 65(9), pp. 83-87. Springer-VDI-Verl. (2013)

Schwebke, S. and Behn, C. Worm-like robotic systems: generation, analysis and shift of gaits using adaptive control� Artificial Intelligence Research. Toronto Vol. 2(1), pp. 12-35. Sciedu Press. (2013)

Schwierz, F. Graphene transistors: status, prospects, and problems� Proceedings of the IEEE. New York, NY [u.a.] Vol. 101(7), pp. 1567-1584. Inst. (2013)

Seeck, A.; Rademacher, W.; Fischer, C.; Haueisen, J.; Surber, R. and Voss, A. Prediction of atrial fibrillation recurrence after cardioversion - interaction analysis of cardiac autonomic regulation� Medical engineering & physics. Vol. 35(3), pp. 376-382. (2013)

Serebryakova, E.; Blau, K. and Hein, M. A. Influence of the reconstruction filter on the performance of a switched-mode power amplifier� Facta Universitatis. Niš Vol. 26(1), pp. 1-10. Univ. (2013)

Serra, C. A.; Khan, I. U.; Chang, Z.; Bouquey, M.; Muller, R.; Kraus, I.; Schmutz, M.; Vandamme, T.; Anton, N.; Ohm, C.; Zentel, R.; Knauer, A. and Köhler, M. Engineering polymer microparticles by droplet microfluidics� Journal of flow chemistry. Budapest Vol. 3(3), pp. 66-75. Akad. Kiadó. (2013)

Sharma, R. K.; Kotterman, W.; Landmann, M. H.; Schirmer, C.; Schneider, C.; Wollenschläger, F.; Del Galdo, G.; Hein, M. A. and Thomä, R. S. Over-the-air testing of cognitive radio nodes in a virtual electromagnetic environment� International journal of antennas and propagation� New York, NY Vol. 2013 Hindawi. (2013)

Shokhovets, S.; Bärwolf, F.; Gobsch, G.; Runge, E.; Köhler, K. and Ambacher, O. Excitons and exciton-phonon coupling in the optical response of GaN� phys. stat. sol. c 11(2), 297-301. (2013)

Shyrokau, B.; Wang, D.; Augsburg, K. and Ivanov, V. Vehicle dynamics with brake hysteresis� Proceedings of the Institution of Mechanical Engineers� London Vol. 227(2), pp. 139-150. Sage Publ. (2013)

Shyrokau, B.; Wang, D.; Savitski, D. and Ivanov, V. Vehicle dynamics control with energy recuperation based on control allocation for independent wheel motors and brake system� International journal of powertrains. Genève Vol. 2(2/3), pp. 153-181. Inderscience Enterprises. (2013)

Contact


194




195



Singh, C. R.; Gupta, G.; Lohwasser, R.; Engmann, S.; Balko, J.; Thelakkat, M.; Thurn-Albrecht, T. and Hoppe, H. Correlation of charge transport with structural order in highly ordered melt-crystallized poly(3-hexylthiophene) thin films� Journal of polymer science. Bognor Regis [u.a.] Vol. 51(12), pp. 943-951. Wiley. (2013)

Sinzinger, S. Optical systems engineering for applications from innovative vision aids to platforms for micro-nano-integration� Photonics in Germany� Berlin Vol� 2013, pp� 67� Trias Consult� (2013)

Sippel, P.; Albrecht, W.; Mitoraj, D.; Eichberger, R.; Hannappel, T. and Vanmaekelbergh, D. Two-photon photoemission study of competing auger and surface-mediated relaxation of hot electrons in CdSe quantum dot solids� Nano Letters 13655. (2013)

Sippel, P.; Schwarzburg, K.; Borgwardt, M.; Elagin, M.; Heitz, S.; Semtsiv, M. P.; Masselink, T.; Hannappel, T. and Eichberger, R. Dynamics and two photon intersubband absorption of photovoltaic quantum structures� IEEE 40th Photovoltaic Specialists Conference (PVSC). , pp. 3254-7. (2014)

Sippel, P.; Supplie, O.; May, M. M.; Eichberger, R. and Hannappel, T. Electronic structures of GaP(100) surface reconstructions probed with two-photon photoemission spectroscopy� Physical Review B 89 165312. (2014)

Skamrova, G. B.; Laponogov, I.; Buchelnikov, A. S.; Shckorbatov, Y. G.; Prylutska, S. V.; Ritter, U.; Prylutskyy, Y. I. and Evstigneev, M. P. Interceptor effect of C 60 fullerene on the in vitro action of aromatic drug molecules� Eur. Biophys. J. Vol. 43(6/7), pp. 265-276. (2014)

Skibitzki, O.; Paszuk, A.; Hatami, F.; Zaumseil, P.; Yamamoto, Y.; Schubert, M. A.; Trampert, A.; Tillack, B.; Masselink, W. T.; Hannappel, T. and Schroeder, T. Lattice-engineered Si1-xGex-buffer on Si(001) for GaP integration� J. Appl. Phys. 11503501. (2014)

Sokolov, I.; Kolesnikov, Y. and Thess, A. Experimental investigation of the transient phase of the Lorentz force response to the time-dependent velocity at finite magnetic Reynolds number� Measurement science and technology. Bristol Vol. 25(12), pp. 125304. IOP Publ. (2014)

Sperl, A.; Kröger, J. and Berndt, R. Oberflächenchemie: Atom für Atom� Chem. Unserer Zeit. Vol. 47, pp. 296-299. (2013)

Sprogies, J.; Scheinert, S. and Hörselmann, I. Analyzing the influence of negative gate bias stress on the transconductance of solution-processed, organic thin-film transistors� Journal of applied physics. Melville, NY Vol. 116(7), pp. 074507. American Inst. of Physics. (2014)

Stapf, S.; Ordikhani-Seyedlar, A.; Ryan, N.; Mattea, C.; Kausik, R.; Freed, D. E.; Song, Y.-Q. and Hürlimann, M. D. Probing maltene-asphaltene interaction in crude oil by means of NMR relaxation� Energy Fuels 28, 2395-2401. (2014)

Steffanson, M. and Rangelow, I. W. Microthermomechanical infrared sensors� Opto-electronics review. Warszawa Vol. 22(1), pp. 1-15. Inst. Fizyki Techn., Wojskowa Akad. Techn. (2014)

Steinisch, M.; Torke, P. R.; Haueisen, J.; Hailer, B.; Grönemeyer, D.; Van Leeuwen, P. and Comani, S. Early detection of coronary artery disease in patients studied with magnetocardiography: An automatic classification system based on signal entropy� Computers in Biology and Medicine. 43(2):144-53, 2013. (2013)

Stelian, C.; Yu, Y.; Li, B.-w. and Thess, A. Influence of velocity profile on calibration function of Lorentz force flowmeter� Applied mathematics and mechanics. Dordrecht [u.a.] Vol. 35(8), pp. 993-1004. Springer. (2014)

Stenroos, M.; Hunold, A. and Haueisen, J. Comparison of three-shell and simplified volume conductor models in magnetoencephalography� Neuroimage, 94:337-48,. (2014)

Stepišnik, J.; Mohorić, A.; Mattea, C.; Stapf, S. and Serša, I. Velocity autocorrelation spectra in molten polymer measured by NMR modulated gradient spin-echo� Europhysics Letters 106, 27007/1-6. (2014)

Stockschläder, P.; Kreismann, J. and Hentschel, M. Curvature dependence of semiclassical corrections to ray optics: how Goos-Hänchen shift and Fresnel filtering deviate from the planar case result� epl. Les Ulis Vol. 107(6), pp. 64001. EDP Sciences. (2014)

Strothkämper, C.; Bartelt, A. F.; Sippel, P.; Hannappel, T.; Schütz, R. and Eichberger, R. Delayed Electron Transfer through Interface States in Hybrid ZnO/Organic-Dye Nano-Structures� Journal of Physical Chemistry C 1177901. (2013)

Stubenrauch, M.; Hanitsch, S.; Fischer, R.; Bartsch, H.; Straube, A.; Hoffmann, M. and Witte, H. BioMEMS for analysis and synthesis in life sciences� Biomedizinische Technik 59(1): 127. (2014)

Supplie, O.; Brückner, S.; Romanyuk, O.; Döscher, H.; Höhn, C.; May, M. M.; Kleinschmidt, P.; Grosse, F. and Hannappel, T. Atomic scale analysis of the GaP/Si(100) heterointerface by in situ reflection anisotropy spectroscopy and ab initio density functional theory� Phys. Rev. B9035301. (2014)

Supplie, O.; Döscher, H.; May, M. M. and Hannappel, T. Heteroepitaxial III-V on Si(100) tandem absorbers structures for photoelectrolysis� AIP Conf. Proc. Vol. 1568, pp. 20. (2013)

Supplie, O.; May, M. M.; Stange, H.; Höhn, C.; Lewerenz, H. and Hannappel, T. Materials for light-induced water splitting: In situ controlled surface preparation of GaPN epilayers grown lattice-matched on Si(100)� Journal of Applied Physics 11513509. (2014)

Synooka, O.; Eberhardt, K. R.; Singh, C. R.; Herrmann, F.; Ecke, G.; Ecker, B.; v. Hauff, E.; Gobsch, G. and Hoppe, H. Influence of thermal annealing on PCDTBT:PCBM composition profiles� Advanced Energy Materials 4(5), 1300981. (2014)

Synooka, O.; Eberhardt, K.-R. and Hoppe, H. Chlorine-free processed high performance organic solar cells� RSC Advances. London Vol. 4(32), pp. 16681-16685. RSC Publishing. (2014)

Synooka, O.; Kretschmer, F.; Hager, M. D.; Himmerlich, M.; Krischok, S.; Gehrig, D.; Laquai, F.; Schubert, U. S.; Gobsch, G. and Hoppe, H. Modification of the active layer/PEDOT:PSS interface by solvent additives resulting in improvement of the performance of organic solar cells� ACS applied materials & interfaces. Washington, DC Vol. 6(14), pp. 11068-11081. Soc. (2014)

Szroeder, P.; Górska, A.; Tsierkezos, N.; Ritter, U. and Strupiński, W. The role of band structure in electron transfer kinetics in low-dimensional carbon� Materialwissenschaft und Werkstofftechnik. Vol. 44(2/3), pp. 226-230. (2013)

Szroeder, P.; Tsierkezos, N. G.; Ritter, U. and Strupiński, W. Nitrogen-doped carbon nanotubes as metal-free catalysts for the oxygen reduction in alkaline and acidic media� Journal of Nanoscience Letters.3(9). (2013)

Terzijska, D.; Porcelli, M. and Eichfelder, G. Multi-objective optimization in the Lorentz force velocimetry framework� Book of Digests & Program OIPE2014, Delft, Netherlands,� (2014)

Thess, A. Thermodynamic efficiency of pumped heat electricity storage� Physical review letters. Ridge, NY Vol. 111(11), pp. 110602. American Physical Society. (2013)

Thess, A. and Boeck, T. Electromagnetic drag on a magnetic dipole interacting with a moving electrically conducting sphere� IEEE transactions on magnetics. New York, NY Vol. 49(6), pp. 2847-2857. IEEE. (2013)

Tonisch, K.; Benzig, R.; Ecke, G. and Pezoldt, J. AlGaN solution growth on 3C-SiC(111)/Si(111) pseudosubstrates� Mater. Sci. Forum, 740-74203-106. (2013)

Tsierkezos, N. G.; Knauer, A. and Ritter, U. Thermodynamic investigation of ferrocyanide/ferricyanide redox system on nitrogen-doped multi-walled carbon nanotubes decorated with gold nanoparticles� Thermochimica Acta76:1-8. (2014)

Tsierkezos, N. G.; Knauer, A. and Ritter, U. Multi-Walled Carbon Nanotubes Modified with Gold Nanoparticles with Various Diameters for the Simultaneous Analysis of Dopamine and Uric Acid in a Single Experiment� Sensor Lett.2(1):153-159. (2014)

Tsierkezos, N. G.; Othman, S. H.; Hafermann, L. and Ritter, U. Electrochemical Sensor Consisting of Nitrogen-Doped Multi-Walled Carbon Nanotubes Decorated with Platinum Nanoparticles� Advanced Electrochemistry.1(2):153-160. (2013)

Tsierkezos, N. G.; Othman, S. H. and Ritter, U. Nitrogen-doped carbon nanotubes modified with gold nanoparticles for simultaneous analysis of N-acetylcysteine and acetaminophen� J. Solid State Electrochem. Vol. 18(3), pp. 629-637. (2014)

Tsierkezos, N. G.; Othman, S. H. and Ritter, U. Nitrogen-doped multi-walled carbon nanotubes for paracetamol sensing� Ionics.19(12):1897-1905. (2013)

Tsierkezos, N. G.; Othman, S. H.; Ritter, U.; Hafermann, L.; Knauer, A. and Köhler, M. Nitrogen-doped multi-walled carbon nanotubes modified with platinum, palladium, rhodium and silver nanoparticles in electrochemical sensing� Journal of nanoparticle research. Dordrecht [u.a.] Vol. 16(10), pp. 2660. Springer Science + Business Media B.V. (2014)

Tsierkezos, N. G. and Ritter, U. Influence of ozone on N-doped multi-walled carbon nanotubes� Journal of Experimental Nanoscience(4):421-431. (2014)

Tsierkezos, N. G. and Ritter, U. Non-enzymatic analysis of cholesterol in acetonitrile solutions� Physics and Chemistry of Liquids2(5):601-607. (2014)

Tsierkezos, N. G. and Ritter, U. Effect of Functionalization of Nitrogen-Doped Carbon Nanotubes on their Electrochemical Properties� Advanced Electrochemistry.1(2):136-141. (2013)

Tsierkezos, N. G.; Ritter, U.; Knauer, A. and Szroeder, P. Electrocatalytic Activity of Nitrogen-Doped Carbon Nanotubes Decorated with Gold Nanoparticles� Electrocatalysis.(1):87-95. (2014)

Tsierkezos, N. G.; Ritter, U. and Scharff, P. Sensor based multi-walled carbon nanotubes for bioanalysis� Chemical Sensors(15). (2014)

Tsierkezos, N. G.; Ritter, U.; Wetzold, N. and Hübler, A. C. Disposable Multiwalled Carbon Nanotube Printed Film Electrochemical Determination of Acetaminophen, Dopamine, and Uric Acid� Analytical Letters7(17):2829-2843. (2014)

Tsierkezos, N. G.; Ritter, U.; Wetzold, N.; Hübler, A. C.; Fischer, T. and Kroll, L. Multi-walled carbon nanotubes printed on thin textile films for electrochemical sensing� Advanced Electrochemistry. Vol. 1(1), pp. 67-74. (2013)

Tsierkezos, N. G.; Szroeder, P. and Ritter, U. Voltammetric study on pristine and nitrogen-doped multi-walled carbon nanotubes decorated with gold nanoparticles� Microchim Acta.81(3-4):329-337. (2014)

Tsierkezos, N. G. and U., R. Electrochemistry of tris(2,2 -bipyridine)ruthenium(II) on nitrogen-doped multi-walled carbon nanotubes� Chemical Sensors.3:8. (2013)

Tsierkezos, N. G.; Wetzold, N.; Hübler, A. C. and Ritter, U. Printed one-time-use carbon nanotube-based films for sensing applications� Sensor letters. Vol. 11(3), pp. 596-602. (2013)

Tsierkezos, N. G.; Wetzold, N.; Hübler, A. C.; Ritter, U. and Szroeder, P. Multi-walled carbon nanotubes printed onto polycarbonate substrate for electrochemical sensing� Sensor letters. Vol. 11(8), pp. 1465-1471. (2013)

Tsierkezos, N. G.; Wetzold, N. and Ritter, U. Electrochemical responses of carbon nanotubes-based films printed on polymer substances� Ionics.19(2):335-341. (2013)

Tsierkezos, N. G.; Wetzold, N.; Ritter, U. and Hübler, A. C. Analysis of dopamine on printed polymer thin film consisting of multi-walled carbon nanotubes� Monatshefte für Chemie. Vol. 144(5), pp. 581-588. (2013)

Tsierkezos, N. G.; Wetzold, N.; Ritter, U. and Hübler, A. C. Preparation and electrochemical performance of novel printed film consisting of multi-walled carbon nanotubes� Journal of Nanoscience Letters.3(9). (2013)

Turkovic, V.; Engmann, S.; Egbe, D. A. M.; Himmerlich, M.; Krischok, S.; Gobsch, G. and Hoppe, H. Multiple stress degradation analysis of the active layer in organic photovoltaics� Solar energy materials & solar cells. Amsterdam Vol. 120(2), pp. 654-668. North Holland. (2014)

Turkovic, V.; Engmann, S.; Tsierkezos, N.; Hoppe, H.; Ritter, U. and Gobsch, G. Long-term stabilization of organic solar cells using hindered phenols as additives� Acs Applied Materials & Interfaces 6 18525-18537. (2014)

Turov, V.; Prylutskyy, Y.; Ugnivenko, A.; Barvinchenko, V.; Krupskaya, T.; Tsierkezos, N. and Ritter, U. Speciation Behavior of Copper(II) Acetate in Simple Organic Solvents – Revealing the Effect of Trace Water� European Journal of Inorganic Chemistry� Vol� 8, pp� 1407-1412� (2014)

Contact


196




197



Turov, V. V.; Prylutskyy, Y. I.; Ugnivenko, A. P.; Barvinchenko, V. N.; Krupskaya, T. V.; Tsierkezos, N. G. and Ritter, U. Low-temperature 1H NMR spectroscopic study of hydration properties of a hybrid system based on nanosilica, DNA and doxorubicin in the presence of C60 fullerene� Low Temperature Physics/Fizika Nizkikh Temperatur.0(3):309-316. (2014)

Turov, V. V.; Ugnivenko, A. P.; Krupskaya, T. V.; Prylutskyy, Y. I.; Schütze, C. and Ritter, U. Hydration properties of nanosilica, modified by adsorbed C 60 fullerene� Materialwissenschaft und Werkstofftechnik. Vol. 44(2/3), pp. 244-248. (2013)

Ulbrich, A.; Reinmöller, M.; Beenken, W. J. D. and Krischok, S. Photoelectron spectroscopy on ionic liquid surfaces - theory and experiment� Journal of molecular liquids. New York, NY [u.a.] Vol. 192, pp. 77-86. Elsevier. (2014)

Vellacheri, R.; Al-Haddad, A.; Zhao, H. P.; Wang, W. X.; Wang, C. L. and Lei, Y. High performance supercapacitor for efficient energy storage under extreme environmental temperatures� Nano Energy 8 231-237. (2014)

Vimieiro, C.; Andrada, E.; Witte, H. and Pinotti, M. A computational model for dynamic analysis of the human gait� Computer Methods in Biomechanics and Biomedical Engineering 18(7) (2013): 799-804. (2013)

Visaveliya, N. and Köhler, J. M. Single-step microfluidic synthesis of various nonspherical polymer nanoparticles via in situ assembling: dominating role of polyelectrolytes molecules� ACS applied materials & interfaces. Washington, DC Vol. 6(14), pp. 11254-11264. Soc. (2014)

Visaveliya, N. and Köhler, J. M. Control of shape and size of polymer nanoparticles in a single step microcontinuous flow process: a case of flower and spherical shapes� Langmuir 30 12180- 12189. (2014)

Visaveliya, N. and Köhler, J. M. A self-seeding synthesis of Ag microrods of tuned aspect ratio: ascorbic acid plays a key role� Nanotechnology. Bristol Vol. 24(34), pp. 345604. IOP Publ. (2013)

Visaveliya, N.; Li, S. and Köhler, J. M. Heterogeneous nanoassembling: microfluidically prepared poly(methyl methacrylate) nanoparticles on Ag microrods and ZnO microflowers� Particle & particle systems characterization. Weinheim Vol. 30(7), pp. 614-623. Wiley-VCH. (2013)

Vorbringer-Dorozhovets, N.; Goj, B.; Machleidt, T.; Franke, K.-H.; Hoffmann, M. and Manske, E. Multifunctional nanoanalytics and long-range scanning probe microscope using a nanopositioning and nanomeasuring machine� Measurement science and technology. - Bristol : IOP Publ. Ltd. Vol. 25.214(4), pp. 44006. (2014)

Voronin, D. P.; Buchelnikov, A. S.; Kostjukov, V. V.; Khrapatiy, S. V.; Wyrzykowski, D.; Piosik, J.; Prylutskyy, Y. I.; Ritter, U. and Evstigneev, M. P. Evidence of entropically driven C 60 fullerene aggregation in aqueous solution� The journal of chemical physics. Vol. 140(10), pp. 104909. (2014)

Wang, C. L.; Fang, Y. G.; Wen, L. Y.; Zhou, M.; Xu, Y.; Zhao, H. P.; De Cola, L.; Hu, W. P. and Lei, Y. Vectorial diffusion for facial solution-processed self-assembly of insoluble semiconductors: a case study on metal phthalocyanines� Chemistry - A European Journal 20 10990-10995. (2014)

Wang, C. L.; Wen, L. Y.; Kups, T.; Mi, Y.; Vellacheri, R.; Fang, Y. G.; Schaaf, P.; Zhao, H. P. and Lei, Y. Growth control of AgTCNQ nanowire arrays by using a template-assisted electro-deposition method� Journal of Materials Chemistry C1) 8003-8006. (2013)

Wang, D.; Gruber, P. A.; Volkert, C. A. and Kraft, O. Influences of Ta passivation layers on the fatigue behavior of thin Cu films� Materials science & engineering� Amsterdam Vol� 610, pp� 33-38. Elsevier. (2014)

Wang, H.; Wang, W. C.; Li, L. Q.; Zhu, J.; Wang, W. X.; Xie, Z. X.; Fuchs, H.; Lei, Y. and Chi, L. F. Surface micro-fluidic patterning and transporting organic small molecules� Small 10549–2552. (2014)

Wang, X. and Kolesnikov, Y. A numerical visualization of physical fields in an electromagnetic pump with rotating permanent magnets� Magnetohydrodynamics. Salaspils Vol. 50(2), pp. 139-156. Inst. of Physics, Univ. of Latvia. (2014)

Weidermann, C.; Sokolov, I. and Thess, A. Lorentz force and joule heat induced in an electrically conducting plate moving with time-dependent velocity under the influence of a homogeneous magnetic field� IEEE transactions on magnetics. New York, NY Vol. 50(8), pp. 7027209. IEEE. (2014)

Weigel, C.; Mehner, H.; Schneider, M. and Hoffmann, M. Passive RFID-auslesbare Sensorik für Verpackungen� Workshop Funktionalisierte Verpackungen - Mehrwert beim Kunden erzeugen, Rudolstadt. (2014)

Weigel, C.; Müller, L.; Grewe, A. and Hoffmann, M. Integration of nanostructured silicon for improving IR-transmission of an optical measurement cuvette� 1st International Conference and 3rd International MacroNano-Colloquium on the Challenges and Perspectives of Functional Nanostructures (CPFN), Ilmenau,. (2014)

Weinberger, S.; Nguyen, T. T.; Ament, C. and Hoffmann, M. Quasi-static micromirror with enlarged deflection based on aluminum nitride thin film springs� Sensors and actuators� Amsterdam [u�a�] Vol� 210, pp� 165-174� Elsevier Science. (2014)

Welker, T.; Geiling, T.; Bartsch, H. and Müller, J. Design and fabrication of transparent and gas-tight optical windows in low-temperature co-fired ceramics� International journal of applied ceramic technology� Westerville, Ohio Vol. 10(3), pp. 405-412. Wiley-Blackwell. (2013)

Wen, L. Y.; Mi, Y.; Wang, C. L.; Fang, Y. G.; Grote, F.; Zhao, H. P.; Zhou, M. and Lei, Y. Cost-effective atomic layer deposition synthesis of Pt nanotube arrays: application for high performance supercapacitor� Small 10162-3168. (2014)

Wendler, S.; Ammon, D.; Kikova, T.; Philippow, I. and Streitferdt, D. Theoretical and practical implications of user interface patterns applied for the development of graphical user interfaces� International Journal on Advances in Software[[Elektronische Ressource]]. [S.l.] Vol. 6(1/2), pp. 25-44. IARIA. (2013)

Wen-Jie Lan Kubeil, C.; Jie-Wen Xiong Bund, A. and White, H. Effect of Surface Charge on the Resistive Pulse Waveshape during Particle Translocation through Glass Nanopores� J. Phys. Chem. C. 118726-2734. (2014)

Wetzstein, O.; Müller, M.; Pacholik, A.; Ortlepp, T.; Fengler, W.; Meyer, H.-G. and Töpfer, H. Event-based modeling of rapid single-flux quantum basic cells with timing jitter� IEEE transactions on applied superconductivity� New York, NY Vol. 23(5), pp. 1301707. IEEE. (2013)

Williamson, A.; Schumann, L.; Hiller, L.; Klefenz, F.; Hörselmann, I.; Husar, P. and Schober, A. Synaptic behavior and STDP of asymmetric nanoscale memristors in biohybrid systems� Nanoscale. Cambridge Vol. 5(16), pp. 7297-7303. RSC Publ. (2013)

Witte, H. SILVER-MOBILITY - Nahfeld-Mobilitätskonzepte für die Altergruppe 50+� Südthüringische Wirtschaft 059. (2014)

Wong, K. M.; Alay-e-Abbas, S. M.; Fang, Y. G.; Shaukat, A. and Lei, Y. Spatial distribution of neutral oxygen vacancies on ZnO nanowire surfaces: An investigation combining confocal microscopy and first principles calculations� Journal of Applied Physics 11434901. (2013)

Wong, K. M.; Alay-e-Abbas, S. M.; Shaukat, A.; Fang, Y. G. and Lei, Y. First-principles investigation of the size-dependent structural stability and electronic properties of O-vacancies at the ZnO polar and non-polar surfaces� Journal of Applied Physics 11314304. (2013)

Wulfmeier, H.; Albrecht, D.; Ivanov, S.; Fischer, J.; Ulrich, S.; Bund, A. and Fritze, H. High-temperature thin-film calorimetry: a newly developed method applied to lithium ion battery materials� J. Mater. Sci. 48585-6596. (2013)

Xie, J. F.; Zhang, J. J.; Li, S.; Grote, F.; Zhang, X. D.; Zhang, H.; Wang, R. X.; Lei, Y.; Pan, B. C. and Xie, Y. Controllable disorder engineering in oxygen-incorporated MoS2 ultrathin nanosheets for efficient hydrogen evolution� Journal of the American Chemical Society 135 17881-17888� (2013)

Yan, H.; Shen, G.; Zetik, R.; Hirsch, O. and Thomä, R. S. Ultra-wideband MIMO ambiguity function and its factorability� IEEE transactions on geoscience and remote sensing� New York, NY Vol. 51(1), pp. 504-519. IEEE. (2013)

Yan, Y.; Hao, B.; Wang, D.; Chen, G.; Markweg, E.; Albrecht, A. and Schaaf, P. Understanding the fast lithium storage performance of hydrogenated TiO2 nanoparticles� Journal of materials chemistry. London [u.a.] Vol. 1(46), pp. 14507-14513. RSC. (2013)

Yang, S. K.; Lapsley, M. I.; Cao, B. Q.; Zhao, C. L.; Zhao, Y. H.; Hao Q. Z.; Kiraly, B.; Scott, J.; Li, W. Z.; Wang, L.; Lei, Y. and J., H. T. Large-Scale fabrication of three-dimensional surface patterns using template-defined electrochemical deposition� Advanced Functional Materials 2320-730. (2013)

Yang, S. K.; Slotcavage, D.; Mai, J. D.; Guo, F.; Li, S. X.; Zhao, Y. H.; Lei, Y.; Cameron, C. E. and Huang, T. J. Electrochemically Created Highly Surface Roughened Ag Nanoplate Arrays for SERS Biosensing Applications� Journal of Materials Chemistry C 2350-8356. (2014)

Yu, Y.; Li, B.-W. and Thess, A. The effect of a uniform magnetic field on vortex breakdown in a cylinder with rotating upper lid� Computers & fluids. Amsterdam [u.a.] Vol. 88, pp. 510-523. Elsevier Science. (2013)

Zaki, T.; Scheinert, S.; Hörselmann, I.; Rödel, R.; Letzkus, F.; Richter, H.; Zschieschang, U.; Klauk, H. and Burghartz, J. N. Accurate capacitance modeling and characterization of organic thin-film transistors� IEEE transactions on electron devices. New York, NY Vol. 61(1), pp. 98-104. IEEE. (2014)

Zec, M.; Uhlig, R. P.; Ziolkowski, M. and Brauer, H. Finite element analysis of nondestructive testing eddy current problems with moving parts� IEEE transactions on magnetics. New York, NY Vol. 49(8), pp. 4785-4794. IEEE. (2013)

Zetik, R.; Kmec, M.; Sachs, J.; Thomä, R. S. and Mecklenbräuker, C. F. Real-time MIMO channel sounder for emulation of distributed ultrawideband systems� International journal of antennas and propagation� New York, NY Vol. 2014 Hindawi. (2014)

Zhan, Z. B. and Lei, Y. Sub-100-nm nanoparticle arrays with perfect ordering, tunable and uniform dimensions fabricated by combining nanoimprinting with ultrathin alumina membrane technique� ACS Nano 8862–3868. (2014)

Zhang, H. C.; Zhou, M.; Fu, Q.; Lei, B.; Lin, W.; Guo, H. S.; Wu, M. H. and Lei, Y. Observation of Defect State in Highly Ordered Titanium Dioxide Nanotube Arrays� Nanotechnology 25 275603. (2014)

Zhao, H. P.; Wang, C. L.; Vellacheri, R.; Zhou, M.; Xu, Y.; Fu, Q.; Wu, M. H.; Grote, F. and Lei, Y. Self-Supported Metallic Nanopore Arrays with Highly-Oriented Nanoporous Structure as Ideally Nanostructured Electrode for Supercapacitor Application� Advanced Materials 26654-7659. (2014)

Zheng, Y.; Wang, W. X.; Fu, Q.; Wu, M. H.; Shayan, K.; Wong, K. M.; Singh, S.; Schober, A.; Schaaf, P. and Y., L. SERS Substrate Based on Large-Area Well-defined Gold Nanoparticle Arrays with High SERS Uniformity and Stability� ChemPlusChem 79 1622–1630. (2014)

Zhou, M.; Bao, J.; Xu, Y.; Zhang, J. J.; Xie, J. F.; Guan, M. L.; Wang, C. L.; Wen, L. Y.; Lei, Y. and Xie, Y. Photoelectrodes Based Upon Mo:BiVO4 Inverse Opals for Photoelectrochemical Water Splitting� ACS Nano 8 7088–7098. (2014)

Zhu, H. O.; Xiao, C.; Cheng, H.; Grote, F.; Zhang, X. D.; Yao, T.; Li, Z.; Wang, C. M.; Wei, S. Q.; Lei, Y. and Xie, Y. Magnetocaloric effects in a freestanding and flexible graphene-based superlattice synthesized with a spatially confined reaction� Nature Communications 5 3690. (2014)

Zikanov, O.; Krasnov, D.; Boeck, T.; Thess, A. and Rossi, M. Laminar-turbulent transition in magnetohydrodynamic duct, pipe, and channel flows� Applied mechanics reviews. New York, NY Vol. 66(3), pp. 030802. ASME. (2014)

Zikanov, O.; Krasnov, D.; Li, Y.; Boeck, T. and Thess, A. Patterned turbulence in spatially evolving magnetohydrodynamic duct and pipe flows� Theoretical and computational fluid dynamics. Berlin Vol. 28(3), pp. 319-334. Springer. (2014)

Zimmermann, K.; Zeidis, I. and Pivovarov, M. Dynamics of two interconnected mass points in a resistive medium� Differential equations and dynamical systems. New Delhi Vol. 21(1/2), pp. 21-28. Springer India. (2013)

Zschäck, S.; Hesse, S.; Amthor, A.; Katzschmann, M.; Schäffel, C. and Ament, C. Vergleich der Scan-Performance bei Nanopositioniersystemen mit großem Bewegungsbereich� Technisches Messen. Berlin Vol. 81(6), pp. 335-342. De Gruyter. (2014)

Zschäck, S.; Klöckner, J.; Gushchina, I.; Amthor, A.; Ament, C. and Fengler, W. Control of nanopositioning and nanomeasuring machines with a modular FPGA based data processing system� Mechatronics. Amsterdam [u.a.] Vol. 23(3), pp. 257-263. Elsevier Science. (2013)

Contact


198




199



Adler, B. and Müller, R. Seltene Erdmetalle: Gewinnung, Verwendung und Recycling� Berichte aus der Biomechatronik, Bd� 10 Ilmenau, Univ�-Verl� (Hrsg. H. Witte) ISBN: 978-3-86360-093-8. (2014)

Dittrich, L. and Hoffmann, M. Chip-integrated solutions for manipulation and sorting of micro droplets and fluid segments by electrical actuation� Berlin [u.a] , pp. 55-72. Springer. (2014)

Fischer, M.; Gorb, S.; Karguth, A.; Mämpel, J. and Witte, H. InspiRat: Biologisch inspirierter Kletterroboter für die externe Inspektion linearer Strukturen� Berichte aus der Biomechatronik, Bd� 8 Ilmenau, Univ�-Verl� (Hrsg. H. Witte) ISBN: 978-3-86360-052-5. (2014)

Grohmann, L.; Bund, A. and Lammel, P. Thermosonisches Drahtbonden auf galvanisch abgeschiedenen Oberflächen. Schriftenreihe Jahrbuch Oberflächentechnik, Band 70, Eugen G. Leuze Verlag KG, Bad Saulgau, Herausgeber Prof. Dr. Timo Sörgel, 253-265. (2014)

Henfling, B.; Blindenhöfer, G.; Coburger, R.; Günther, K. and Bergmann, J. P. AWUSYS. Entwicklung eines hochpräzisen und zeiteffizienten industriellen Auswuchtsystems� Ilmenau , pp� VIII, 101 S� Univ.-Verl. Ilmenau. (2014)

Jiménez López, O. E. Development of biomechatronic devices for measurement of wrenches occuring in animal and human prehension� Berichte aus der Biomechatronik, Bd. 9 Ilmenau Univ.-Verl. (Hrsg. H. Witte). ISBN: 978-3-86360-102-7. (2014)

Labisch, S. and Weber, C. Technisches Zeichnen. Selbstständig lernen und effektiv üben� Wiesbaden , pp. XI, 304 S. Springer Vieweg. (2013)

Thomä, R. Ultra-wideband radio technologies for communications, localization and sensor applications� Rijeka , pp. XXII, 488 S. Intechopen.com. (2013)

Books / Book chapters Conference Proceedings

Amthor, A.; Kaiser, I.; Rogge, N. and Weis, H. Analysis, physically motivated modeling and systems identification of electromagnetic force compensated balances� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Atanasković, A.; Maleš Ilić, N.; Blau, K. and Đorić, A. A novel linearization technique based on modified baseband signal that modulates carrier second harmonic� 11th International Conference on Telecommunication in Modern Satellite, Cable and Broadcasting Services (TELSIKS), 2013. Piscataway, NJ Vol. 2013, pp. 192-195. IEEE. (2013)

Augustin, S. and Fröhlich, T. Neufassung der Richtlinie VDI/VDE 3522 „Zeitverhalten von Berührungsthermometern“� Temperatur 2013� Braunschweig [u�a�] Vol� 2013, pp� 29-34� Physikalisch-Techn. Bundesanst. (2013)

Bances, E.; Schmidt, T.; Helbig, T. and Witte, H. An ear-pinna acoustic analysis coupled with an ear-canal emulator 711� Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau. (2014)

Bartsch, H.; Töpfer, J.; Löhnert, R.; Bierlich, S.; Barth, S.; Capraro, B. and Müller, J. Integrierte LC-Glieder in keramischen LTCC-Schaltungsträgern� MikroSystemTechnik Kongress 2013, 14.-16. Oktober 2013, Aachen: VDE Verlag ISBN 978-3-8007-3555-6. (2013)

Bäumer, R.; Miranda, J. A. and Witte, H. Do Argiope argentata spiders optimize their spider webs for unified eigenfrequencies?� Kesel, Antonia B. & Zehren, Doris (Hrsg). 6. Bionik-Kongress 189–192. (2013)

Behn, C.; Schmitz, T.; Witte, H. and Zimmermann, K. Animal vibrissae modeling and adaptive control of bio-inspired sensors� Advances in computational intelligence ; Pt� 2� Berlin [u�a] , pp� 159-170. Springer. (2013)

Chatterjee, D.; Blau, K. and Hein, M. A. Highly linear microwave signal detection for cognitive radio� GeMiC 2014. Berlin [u.a.] Vol. 2014 VDE-Verl. (2014)

Čizmović, M.; Kovač, J.; Milosavljević, M.; Petrović, S.; Dražić, G.; Mitrić, M.; Obradović, M.; Schaaf, P. and Peruško, D. Intermixing in Al/Ti multilayer structures induced by nanosecond laser pulses� Physica scripta. Bristol Vol. 2013(157), pp. 014008. IoP Publ. (2013)

Cu-Nguyen, P.-H.; Grewe, A.; Endrödy, C.; Sinzinger, S.; Zappe, H. and Seifert, A. Compact tunable hyperspectral imaging system� IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS), 2014. , pp. 1167-1170. (2014)

Diethold, C.; Kühnel, M. and Fröhlich, T. Development of a force displacement measurement device for the determination of spring constants� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Dittrich, L.; Endrödy, C. and Hoffmann, M. Mikropumpe mit elektrostatischem Direktantrieb� MikroSystemTechnik Kongress� Aachen , pp� 14-16� VDE Verlag� (2013)

Faenger, B.; Becker, F.; Brandl, M.; Fränzel, N.; Holder, S.; Köhring, S.; Lutherdt, S.; Michaelis, A.; Weichert; N.P., S.; Scholle, H.-C.; Zimmermann, K.; Augsburg, K.; Ament, C.; Linß, G.; Witte, H.; Pezoldt, K. and Wenzel, A. Mobilitätssysteme für Best Ager (50plus): Neue Präventionsansätze� 20. Erfurter Tage „“Prävention von arbeitsbedingten Gesundheitsgefahren und Erkrankungen““, Bussert & Stadeler, Hrsg.: Dienstbühl I.; Scholle H.C., Stadeler M.63-375. (2013)

Fehling, T.; Fröhlich, T.; Heydenbluth, D.; Geyer, M. and Schüler, R. Vacuum transfer system for loading the Sartorius prototype mass comparator CCL1007� 56� Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia� Ilmenau , pp� Online-Ressource (PDF-Datei: 4 S., 513,7 KB). ilmedia. (2013)

Fiedler, B.; Gerlach, E.; Husung, I.; Zeidis, I.; Zimmermann, K.; Füßl, R. and Manske, E. Positioning with nanometre precision requires a high tech Nanopositioning and Nanomeasuring Machine and optimal machine setup� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Fremerey, M and Witte, H. A joint with tunable compliance for changing locomotion patterns� Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau. (2014)

Fremerey, M.; Feierabend, M.; Griebel, S.; Witte, H. and Zentner, L. A decubitus preventing adaptive mat inspired by snail tentacles� Kesel, A. B. & Zehren, D.(Hrsg). 6. Bionik- Patente aus der Natur Kongress 212–217. (2013)

Fremerey, M.; Köhring, S.; Nassar, O.; Schöne, M.; Weinmeister, K.; Becker, F.; Đorđević, G. and Witte, H. Design of a phase-shifting double-wheg-module for quadruped robots� Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau. (2014)

Fremerey, M.; Köhring, S.; Nassar, O.; Schöne, M.; Weinmeister, K.; Becker, F.; Đorđević, G. S. and Witte, H. A phase-shifting double-wheg-module for realization of wheg-driven robots� Biomimetic and Biohybrid Systems. Lecture Notes in Computer Science 860874-377. (2014)

Fremerey, M.; Weyrich, S.; Voges, D. and Witte, H. A small-sized underactuated biologically inspired aquatic robot� Biomimetic and Biohybrid Systems. Lecture Notes in Computer Science 860874-377. (2013)

Garbers, J.; Gehrmann, S.; Augustin, S.; Fröhlich, T.; Irrgang, K. and Lippmann, L. Metrological optimazition of thermocouples� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Geiling, T.; Dressler, L.; Welker, T. and Hoffmann, M. Fine dust measurement with electrical fields - concept of a hybrid particle detector� 9th IMAPS/AcerS International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystems Technologies (CICMT 2013). Red Hook, NY Vol. 2014, pp. 131-136. Curran. (2014)

Geinitz, V. and Kletzin, U. Properties of torsion springs before and after heat treatment� Shaping the future by engineering. Ilmenau Vol. 2014, pp. 100-101. Univ.-Verl. Ilmenau. (2014)

Geis, A.; Husung, S.; Weber, C.; Füßl, R. and Manske, E. Vectorial tolerances for the uncertainty analysis of precision measurement devices� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Gevorgyan, V. and Kletzin, U. Tribological behavior and tribological model of shot-peened helical spring wires� Shaping the future by engineering / Ilmenau Scientific Colloquium. Technische Universität Ilmenau ; 58 (Ilmenau) : 2014.09.08-12. - Ilmenau : Univ.-Bibliothek, ilmedia. (2014)

Goj, B.; Bartsch, H.; Hanitsch, S.; Hoffmann, M. and Müller, J. Temperatur- und Feuchtesensor basierend auf planarisierten LTCC-Oberflächen� Mikro-Nano-Integration : Beiträge des 5. GMM-Workshops, 8. - 9. Oktober 2014 in Ilmenau. - Berlin : VDE-Verl, S. 127-130. (2014)

Goj, B.; Dressler, L. and Hoffmann, M. Non-contact measurements of three-dimensional surfaces utilizing a miniaturized uniaxial nanoprobe� ISMTII 2013. Aachen , pp. 138. Apprimus-Verl. (2013)

Goj, B.; Dressler, L. and Hoffmann, M. Non-contact biaxial nanoprobe utilized for surface measurements of MEMS� Technical proceedings of the 2013 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2013� Boca Raton, Fla� [u.a.] Vol. 2013, pp. 197-200. CRC Press. (2013)

Goj, B.; Dressler, L. and Hoffmann, M. Resonanter berührungsloser Mikrotastkopf in Silicium-Mikromechanik� Proceedings MikroSystemTechnik Kongress 2013, 14�-16� Oktober 2013, Aachen: VDE Verlag. (2013)

Götte, J.; Shinohara, S. and Hentschel, M. Are Fresnel filtering and the angular Goos-Hänchen shift the same?� Bad Honnef Vol. 2013 DPG. (2013)

Granzner, R.; Schwierz, F.; Engert, S. and Töpfer, H. Performance fluctuations in 10-nm trigate metal-oxide-semiconductor field-effect transistors: impact of the channel geometry� Japanese journal of applied physics. Tokyo Vol. 52(4) IOP Publ. (2013)

Grewe, A.; Endrödy, C.; Fütterer, R.; Cu-Nguyen, P.-H.; Steiner, S.; Hillenbrand, M.; Correns, M.; Hoffmann, M.; Linß, G.; Zappe, H.; Seifert, A.; Kley, E. B. and Sinzinger, S. Opto-mechanische Mikrosysteme zur hyperspektralen Bildgebung� Proceedings MikroSystemTechnik Kongress 2013, 14�-16� Oktober 2013, Aachen: VDE Verlag. (2013)

Grieseler. M. Stubenrauch, R.; Michael, S.; Klaus, J.; Tonisch, K.; Pezoldt, J. and Schaaf, P. Ermittelung mechanischer Eigenschaften neuer Materialien mittels freistehender Balkenstrukturen� S. 209 – 210, In: Thüringer Werkstofftag 2013 - Wissenschaftliche Beiträge, Schriftenreihe Werkstofftechnik Aktuell Bd. 9, Hrsg. P. Schaaf, E. Rädlein, Universitätsverlag Ilmenau, Ilmenau� (2013)

Günschmann, S.; Fischer, M. and Müller, J. Silicon-Ceramic-Silicon-Wafercompound fabricated by using nanostructured Siliconsurfaces and a ceramic with adapted thermal expansion coefficient� WaferBond ’13, Conference on Waferbonding for Microsystems 3D- and Wafer Level Integration, Stockholm, Sweden, December 5-6,� (2013)

Günschmann, S.; Mannebach, H.; Steffensky, J.; Fischer, M. and Müller, J. Herstellung einer Messküvette als Teil eines Messsensors für Echtzeit-Ölqualitätsmessungen� Von Bauelementen zu Systemen� Berlin [u�a�] Vol� 2013, pp� 810-813. VDE-Verl. (2013)

Günschmann, S.; Müller, L.; Fischer, M.; Hoffmann, M. and Müller, J. Selektive Erzeugung von Nanostrukturen auf einer Waferoberfläche zur Realisierung von optischen und mechanischen Funktionen beim Aufbau eines Echtzeitölsensors� Mikro-Nano-Integration : Beiträge des 5. GMM-Workshops, 8. - 9. Oktober 2014 in Ilmenau. - Berlin : VDE-Verl., S. 69-74. (2014)

Contact


200




201



Güther, T.; Bönicke, H.; Ament, C.; Augustin, S. and Fröhlich, T. A model-based temperature estimator for improving sensor dynamics in vehicle exhaust systems� 39� Annual Conference of the IEEE Industrial Electronics Society Wien Tagungsband S. 3852-3857. (2013)

Gutzeit, N.; Appelfelder, M.; Reinlein, C.; Fischer, M. and Müller, J. LTCC Membranen mit integrierten Heizern, Temperatur- und Dehnungssensorik� MikroSystemTechnik Kongress 2013, 14.-16. Oktober 2013, Aachen: VDE VerlagSBN 978-3-8007-3555-6. (2013)

Hähnlein, B.; Tonisch, K.; Ecke, G.; Grieseler, R.; Michael, S.; Schaaf, P. and Pezoldt, J. AlGaN based MEMS structures� Physica status solidi. Berlin Vol. 11(2), pp. 239-243. Wiley-VCH. (2014)

Hampl, S. and Hoffmann, M. Piezoelektrische AlN-Bimorphe als niederfrequent-resonante Mikroaktoren mit großem Stellweg� Proceedings MikroSystemTechnik Kongress 2013, 14�-16� Oktober 2013, Aachen: VDE Verlag. (2013)

Hampl, S.; Leistritz, B.; Saft, B.; Hoffmann, M. and Hennig, E. Micromechanical, vertical comb-drive-structures for the construction of an electrostatic energy harvester� Proceedings EAS 2014 - 7� GMM-Workshop Energieautarke Sensorik, Magdeburg, 24.-25.02.2014, S. 14-19. (2014)

Hampl, S.; Leistritz, B.; Saft, B.; Hoffmann, M. and Hennig, E. Ein- und mehrlagige vertikale Comb-Drive-Strukturen zur kapazitiven, niederfrequenten Energiegewinnung� Proceedings MikroSystemTechnik Kongress 2013, 14�-16� Oktober 2013, Aachen: VDE Verlag. (2013)

Hanitsch, S.; Hampl, J.; Fischer, R.; Tobola, J.; Stubenrauch, M.; Schober, A.; Witte, H. and Hoffmann, M. Integration of hydrogels into BioMEMS� Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau. (2014)

Hartmann, L.; Reich, R.; Kletzin, U. and Zentner, L. Approaches on material analysis and modeling of bouncing putty� Shaping the future by engineering / Ilmenau Scientific Colloquium. Technische Universität Ilmenau ; 58 (Ilmenau) : 2014.09.08-12. - Ilmenau : Univ.-Bibliothek, ilmedia. (2014)

Helbig, T.; Voges, D.; Niederschuh, S.; Schmidt, M. and Witte, H. The mechanics of carpal vibrissae of Rattus norvegicus during substrate contact� Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau. (2014)

Helbig, T.; Voges, D.; Niederschuh, S.; Schmidt, M. and Witte, H. Characterizing the substrate contact of carpal vibrissae of rats during locomotion� Biomimetic and Biohybrid Systems. Lecture Notes in Computer Science 860899-401. (2014)

Hesse, S.; Schäffel, C.; Zschäck, S.; Ament, C.; Müller, A. and Manske, E. Scan performance of nanopositioning systems with large travel range� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Hoffmann, M.; Goj, B. and Dressler, L. Kontaktlose Oberflächenantastung in bis zu drei Raumrichtungen zur Vermeidung von Sticking-Effekten in der Koordinatenmesstechnik� 6� Kolloquium Mikroproduktion: Braunschweig, 8. Oktober 2013. - Aachen : Shaker., B23, insges. 6 S. (2013)

Hofmann, N.; Mastylo, R.; Manske, E. and Theska, R. A compact tactile surface profiler for multi-sensor applications in nano measuring machines� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Hohmann, M.; Breitkreutz, P.; Schalles, M. and Fröhlich, T. Calibration of heat flux sensors with small heat fluxes� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Hohmann, M.; Marin, S.; Schalles, M.; Krapf, G. and Fröhlich, T. Metall-Blockkalibrator mit Wärmestromsensoren und adiabatischem Schild� Sensoren und Messsysteme Nürnberg insgesamt 6 Seiten. (2014)

Ibraheam, M.; Krauß, A.; Irteza, S. and Hein, M. A. Reduction of mutual coupling in compact antenna arrays using element tilting� GeMiC 2014� Berlin [u.a.] Vol. 2014 VDE-Verl. (2014)

Jatal, W.; Tonisch, K.; Baumann, U.; Schwierz, F. and Pezoldt, J. GaN HEMTs on Si substrate with high cutoff frequency� p� 117 - 120, In: Conference Proceedings of the 10th International Conference on Advanced Semiconductor Devices and Microsystems (ASDAM 2014), 20th - 22nd October 2014, Smolenics Castle, Slovakia, ISBN 978-1-4799-5474-2. (2014)

John, K.; Theska, R.; Manske, E. and Büchner, H. The influence of polarization changes introduced by deflecting elements to interferometric measurements� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Kletzin, U. 50 Jahre Federnforschung in Ilmenau� Neueste Erkenntnisse zu Funktion, Berechnung, Prüfung und Gestaltung von Federn und Werkstoffen / Ilmenauer Federntag ; (Ilmenau) : 2013.09.26. - Ilmenau : Verl. ISLE, S. 3-10. (2013)

Köchert, P.; Weichert, C.; Flügge, J.; Wurmus, J. and Manske, E. Digital beat frequency control of an offset-locked laser system� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Köhring, S.; Lutherdt, S.; Fremerey, M. and Witte, H. A wheg-axle-tracking mechanism for passenger transport purposes� Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau. (2014)

Krapf, G.; Schwesinger, F. and Fröhlich, T. High-precision analog interfaces for low-latency PC-in-the-loop controller� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Kühn, S.; Stephan, R.; Blau, K. and Hein, M. A. Transistor-based electrically tuneable reactance circuits for metamaterial transmission lines� GeMiC 2014. Berlin [u.a.] Vol. 2014 VDE-Verl. (2014)

Kühnel, M.; Rivero, M.; Diethold, C.; Hilbrunner, F. and Fröhlich, T. Dual axis tiltmeter with nanorad resolution based on commercial force compensation weigh cells� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Laqua, D.; Hampl, S.; Hoffmann, M. and Husar, P. Proof of concept for energy harvesting using piezoelectric microstructures for intelligent implants using eye-motion classified with the Integrated Eyetracker� World Congress on Medical Physics and Biomedical Engineering ; Vol. 2. - [Berlin] : Springer. , pp. 1397-1400. (2013)

Leopold, S.; Geiling, T.; Fliegner, C.; Pätz, D.; Sinzinger, S.; Müller, J. and Hoffmann, M. Multifunctional LTCC substrates for thermal actuation of tunable micro-lenses made of aluminum nitride membranes� 9th IMAPS/AcerS International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystems Technologies (CICMT 2013). Red Hook, NY Vol. 2014, pp. 124-130. Curran. (2014)

Leopold, S.; Pätz, D.; Knöbber, F.; Ambacher, O.; Sinzinger, S. and Hoffmann, M. Tunable cylindrical microlenses based on aluminum nitride membranes� MOEMS and miniaturized systems XII, 861611 (March 13, 2013). (2013)

Leopold, S.; Pätz, D.; Sinzinger, S. and Hoffmann, M. Adaptive Mikrolinsen basierend auf Aluminiumnitrid Membranen� Proceedings MikroSystemTechnik Kongress 2013, 14�-16� Oktober 2013, Aachen: VDE Verlag. (2013)

Lutherdt, S.; Becker, F.; Brandl, M.; Faenger, B.; Fränzel, N.; Fremerey, M.; Köhring, S.; Lawin, M.; Michaelis, A.; Weichert, F. and Witte, H. Silver-Mobility - near field mobility concepts for the age group 50+� Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau. (2014)

Lux, R.; Kletzin, U.; Geinitz, V. and Beyer, P. Long-term stability of patented cold drawn steel wires� Shaping the future by engineering / Ilmenau Scientific Colloquium. Technische Universität Ilmenau ; 58 (Ilmenau) : 2014.09.08-12. - Ilmenau : Univ.-Bibliothek, ilmedia. (2014)

Lux, R.; Kletzin, U.; Geinitz, V. and Beyer, P. Anrissverhalten von patentiert gezogenen Drähten� Neueste Erkenntnisse zu Funktion, Berechnung, Prüfung und Gestaltung von Federn und Werkstoffen / Ilmenauer Federntag ; (Ilmenau) : 2013.09.26. - Ilmenau : Verl. ISLE, S. 21-25. (2013)

Manske, E.; Füßl, R.; Mastylo, R.; Vorbringer-Dorozhovets, N.; Birli, O. and Jäger, G. Ongoing trends in precision metrology� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Marin, S.; Hohmann, M.; Schalles, M.; Krapf, G. and Fröhlich, T. Insert with a multiple fixed-point cell for a dry block calibrator� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Markweg, E. and Hoffmann, M. Optical scanners based on thermo-optical tuning of an integrated-optical waveguide mode� MOEMS and miniaturized systems XII, 86160A (March 13, 2013). (2013)

Markweg, E.; Nguyen, T. T.; Ament, C.; Hoffmann, M.; Schädel, M. and Brodersen, O. Integration of a position photodiode for a micro laser tracker system� (2013)

Markweg, E.; Schädel, M.; Brodersen, O.; Ortlepp, H. G.; Hoffmann, M. and Mollenhauer, O. Mikrotechnische Umsetzung eines integriert optischen Michelson-Interferometers für Auflösungen im Sub-Nanometerbereich� Mikro-Nano-Integration : Beiträge des 5. GMM-Workshops, 8. - 9. Oktober 2014 in Ilmenau. - Berlin : VDE-Verl, S. 107-111. (2014)

Markweg, E.; Weinberger, S.; Nguyen, T. T.; Schädel, M.; Brodersen, O.; Ament, C. and Hoffmann, M. Mikrolasertracker zur multisensorischen 3D-Koordinatenmessung� Proceedings MikroSystemTechnik Kongress 2013, 14�-16� Oktober 2013, Aachen: VDE Verlag. (2013)

Mehner, H.; Leopold, S. and Hoffmann, M. Variation des intrinsischen Stressgradienten dünner Aluminiumnitridschichten� Proceedings MikroSystemTechnik Kongress 2013, 14�-16� Oktober 2013, Aachen: VDE Verlag. (2013)

Mischo, M.; Bitterling, M.; Himmerlich, M.; Krischok, S.; Ambacher, O. and Cimalla, V. Seebeck ozone sensors� Proc� 17th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS & EUROSENSORS XXVII), June 16-20 2013, Barcelona, Spain, 1645-1648. (2013)

Möller, R.; Horn, V.; Moretton, S.; Tschmelak, J.; Schalles, M.; Mammen, H. and Fröhlich, T. Hochpräzise Temperaturmessung in Präzisionsklimakammern bzw. –geräten im Raumtemperaturbereich� PTB Fachtagung Temperatur Berlin Tagungsband S. 23 - 28. (2013)

Müller, A.; Mastylo, R.; Vorbringer-Dorozhovets, N. and Manske, E. Markers for referencing topography measurement data of optical surfaces� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Müller, J. Wide band measurement of dielectric properties of electronic assembly materials inside a LTCC fluidic structure� 9th IMAPS/AcerS International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystems Technologies (CICMT 2013). Red Hook, NY Vol. 2014, pp. 41-46. Curran. (2014)

Müller, L.; Günschmann, S.; Fischer, M.; Müller, J.; Hoffmann, M.; Käpplinger, I.; Brode, W. and Biermann, S. Nanostrukturen als Problemlöser - Emissionserhöhung und Interferenzvermeidung am Bsp. eines IR-basierten Fluidsensors� Mikro-Nano-Integration : Beiträge des 5. GMM-Workshops, 8. - 9. Oktober 2014 in Ilmenau. - Berlin : VDE-Verl., S. 127-130. (2014)

Müller, L.; Günschmann, S.; Fischer, M.; Müller, J.; Hoffmann, M.; Käpplinger, I.; Brode, W.; Magi, A.; Biermann, S.; Pignanelli, E. and Schütze, A. Entwicklung und Optimierung mikrotechnischer Silizium- und Keramikkomponenten zur Realisierung eines Fluidiksensors� 17� ITG-/GMA-Fachtagung Sensoren und Messsysteme 2014, Nürnberg, Germany, 03.-04. Juni. (2014)

Müller, L.; Hoffmann, M.; Käpplinger, I.; Brode, W. and Biermann, S. Silicium-Platin Nanostrukturen für hochgradig Infrarot-emissive Oberflächen in Hotplate-Emittern� Proceedings MikroSystemTechnik Kongress 2013, 14�-16� Oktober 2013, Aachen: VDE Verlag. (2013)

Müller, R.; Herrmann, R.; Wollenschläger, F.; Schulz, A.; Hein, M. and Thomä, R. A compact ECC-band horn antenna for remote monitoring of vital signs at home environments� 7th European Conference on Antennas and Propagation (EuCAP), 2013. Piscataway, NJ Vol. 2013, pp. 1479-1483. IEEE. (2013)

Nassar, O.; Fremerey, M.; Abdelhameed, M. M.; Tolbah, F. A. and Witte, H. Wheg-module with electromagnetic spokes, Ilmenau� Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau. (2014)

Nassar, O.; Fremerey, M.; Witte, H.; Abdelhameed, M. M. and Tolbah, F. A. A wheg-module with electromagnetic spokes� Shaping the future by engineering : 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau. , pp. 77. (2014)

Oliveira, R.; Lepikson, H.; Winter, S.; Theska, R.; Fröhlich, T.; Bitencourt, C. and Machado, R. New proposals for the dynamic tests of torque transducers� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Contact


202




203



Pezoldt, J. and Tonisch, K. FTIR-Ellipsometrie an Mischkristallen von Gruppe III-Nitriden� S� 107 - 114, In: Thüringer Werkstofftag 2013 - Wissenschaftliche Beiträge, Schriftenreihe Werkstofftechnik Aktuell Bd. 9, Hrsg. P. Schaaf, E. Rädlein, Universitätsverlag Ilmenau, Ilmenau� (2013)

Podoskin, D.; Shaukat, N.; Brückner, K.; Blau, K.; Mehner, H.; Gropp, S.; Hoffmann, M. and Hein, M. A. RF oscillators based on piezoelectric aluminium nitride MEMS resonators� GeMiC 2014 / German Microwave Conference ; (Aachen) : 2014.03.10-12. - Berlin [u.a.] : VDE-Verl., insges. 4 S. (2014)

Porzig, K.; Carlstedt, M.; Ziolkowski, M.; Brauer, H. and Töpfer, H. Reverse engineering of ECT probes for nondestructive evaluation of moving conductors� 40th Annual Review of Progress in Quantitative Nondestructive Evaluation. Melville, NY , pp. 1519-1525. AIP Publ., American Inst. of Physics. (2014)

Pudis, D.; Suslik, L.; Skriniarova, J.; Kovac, J.; Kovac, J.; Kubicova, I.; Martincek, I.; Hascik, S. and Schaaf, P. Effect of 2D photonic structure patterned in the LED surface on emission properties� Applied surface science� Amsterdam [u�a�] Vol� 269, pp� 161-165. Elsevier. (2013)

Pufke, M.; Hilbrunner, F.; Diethold, C. and Fröhlich, T. Precision and low cost position detection using capacitive sensor technology� 56� Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia� Ilmenau , pp� Online-Ressource (PDF-Datei: 6 S., 624,7 KB). ilmedia. (2013)

Pufke, M.; Hilbrunner, F.; Diethold, D. and Fröhlich, T. Capacitive sensor technology based on area variation for precise position detection� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Rahneberg, I. and Fröhlich, T. Contact materials for mass artifacts� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Reich, R. and Kletzin, U. Möglichkeiten zur Übertragung von dynamischen Materialkennwerten aus Umlaufbiegeprüfungen auf Schraubendruckfedern� Neueste Erkenntnisse zu Funktion, Berechnung, Prüfung und Gestaltung von Federn und Werkstoffen / Ilmenauer Federntag ; (Ilmenau) : 2013.09.26. - Ilmenau : Verl. ISLE, S. 51-59. (2013)

Rivero, M.; Kühnel, M. and Fröhlich, T. High precision dual axis tilt stage� Shaping the future by engineering. Ilmenau Vol. 2014, pp. 40. Univ.-Verl. Ilmenau. (2014)

Rogge, N.; Engwicht, M.; Welsch, S.; Hilbrunner, F. and Fröhlich, T. Hygrostat based on adsorption processes controlled by a high precision chilled dew point mirror� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Rogge, N.; Fröhlich, T. and Hilbrunner, F. Ein neuartiger Präzisionshygrostat nach dem Adsorptionsverfahren� PTB Fachtagung Temperatur Berlin Tagungsband S. 269 - 275. (2013)

Rosenberger, M.; Grewe, A.; Manske, E.; Hillenbrand, M.; Fröhlich, T.; Sinzinger, S.; Linß, G.; Fütterer, R. and Correns, M. Hyper- and multispectral imaging systems - a survey of different approaches at the Technische Universität Ilmenau� Shaping the future by engineering. Ilmenau , pp. 53. Univ.-Verl. Ilmenau. (2014)

Schalles, M.; Flügge, J. and Köning, R. Reduction of thermal effects on precise dimensional measurements� Shaping the future by engineering. Ilmenau , pp. 137. Univ.-Verl. Ilmenau. (2014)

Schilling, C. Biological structures and technical design - a bio-mimetic approach� Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau. (2014)

Schleichert, J.; Rahneberg, I. and Fröhlich, T. Calibration of a novel six-degree-of-freedom force/torque measurement system� Asis Pacific Symposium on Measurements of Mass, Force and Torque Singapore Bd. 24, S. 1360017 – 1360025. (2013)

Schmidt, M.; Witte, H.; Zimmermann, K.; Niederschuh, S.; Helbig, T.; Voges, D.; Husung, I.; Volkova, T.; Will, C.; Behn, C.; Steigenberger, J. and Klauer, G. Technical, non-visual characterization of substrate contact using carpal vibrissae as a biological model: an overview� Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau. , pp. 81. (2014)

Schulz, A.; Stöpel, D.; Welker, T.; Müller, R.; Wollenschläger, F. and Müller, J. Optimized wire-bond transitions for microwave applications up to 67 GHz using the low loss LTCC material DuPont 9k7� 2013 European Microelectronics and Packaging Conference� Piscataway, NJ Vol. 2013 IEEE. (2013)

Schwesinger, F.; Krapf, G. and Fröhlich, T. PC-based low latency controller for dynamic mechatronic systems� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Stadnyk, B.; Fröhlich, T. and Khoma, Y. Improvement of metrological characteristics of portable impedance analyzers� 58. Internationales Wissenschaftliches Kolloquium der TU Ilmenau, Erschienen in Ilmedia. (2014)

Supplie, O.; Bruckner, S.; Romanyuk, O.; May, M. M.; Doscher, H.; Kleinschmidt, P.; Stange, H.; Dobrich, A.; Hohn, C.; Lewerenz H. J., G. F. and Hannappel, T. An experimental-theoretical atomic-scale study - in situ analysis of III-V on Si(100) growth for hybrid solar cells� IEEE 40th Photovoltaic Specialists Conference (PVSC) (2014) 2797-9. (2014)

Synooka, O.; Kretschmer, F.; Hager, M. D.; Schubert, U.; Gobsch, G. and Hoppe, H. Impact of methanol top-casting or washing on the polymer solar cell performance� Proceedings of the SPIE- The International Society for Optical Engineering 8811 881117(7pp.). (2013)

Uhlig, R. P.; Zec, M. and Brauer, H. Lorentz Force Eddy Current Testing - Model Experiments and Numerical Calculations for Deep Lying Defects� J.M.A. Rebello, F. Kojima und T. Chady: Electromagnetic Nondestructive Evaluation (XVI); IOS Press, Amsterdam, Berlin, Tokyo, Washington DC, 2014, S. 83-33. (2014)

Vlaic, C.; Ivanov, S.; Yan, Y.; Wang, D.; Schaaf, P. and Bund, A. Electrochemical performance of nanoporous silicon nanopillars as anodes for Li-ion batteries� Thüringer Werkstofftag 2013� Ilmenau Vol� 2013, pp� 211-212� Univ.-Verl. Ilmenau. (2013)

Voges, D.; Fremerey, M.; Hörnschemeyer, D.; Krekeler, M.; Schomburg, K.; Schilling, C. and Witte, H. The cilia field as a paragon for technical macro transport� Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau. (2014)

Vorbringer-Dorozhovets, N.; Füßl, R. and Manske, E. Application of the metrological SPM for long distance measurements� Shaping the future by engineering. Ilmenau Vol. 2014, pp. 14. Univ.-Verl. Ilmenau. (2014)

Wang, D.; Ihlemann, J. and Schaaf, P. Complex patterned gold structures fabricated via laser annealing and dealloying� Applied surface science� Amsterdam Vol� 302, pp� 74-78� Elsevier. (2014)

Wang, Y.-C.; Shuyu, L.-H.; Chang, C.-P. and Manske, E. Signal interpolation method for quadrature phase-shifted Fabry-Perot interferometer� 58. Internationales Wissenschaftliches Kolloquium der TUIlmenau, Erschienen in Ilmedia. (2014)

Weigel, C.; Schneider, M.; Hoffmann, M.; Kahl, S. and Jurisch, R. Niedrig-Energie-Sensor für den Sauerstoffnachweis in Verpackungen mittels RFID� 17� ITG-/GMA-Fachtagung Sensoren und Messsysteme 2014,Nürnberg, Germany, 03.-04. Juni. (2014)

Weinberger, S. and Hoffmann, M. Aluminum nitride supported 1D micromirror with static rotation angle >11°� MOEMS and miniaturized systems XII, 86160E (March 13, 2013). (2013)

Weiß, M.; Steigenberger, J. and Geinitz, V. Bestimmung des E-Moduls und der Federbiegegrenze von Federstahldraht mittels 3-Punkt-Biegeversuch� Neueste Erkenntnisse zu Funktion, Berechnung, Prüfung und Gestaltung von Federn und Werkstoffen / Ilmenauer Federntag ; (Ilmenau) : 2013.09.26. - Ilmenau : Verl. ISLE, S. 103-110. (2013)

Witte, H.; Carl, K.; Voges, D.; Schilling, C.; Zimmermann, K.; Loepelmann, P.; Schmitz, A. and Behn, C. Zur funktionellen Morphologie mystacialer Vibrissen bei Rattus norvegicus� Kesel, A. B. & Zehren, D. (Hrsg) 6. Bionik- Patente aus der Natur Kongress:. , pp. 358-–364. (2013)

Witte, H.; Fremerey, M.; Weyrich, S.; Mämpel, J.; Fischheiter, L.; Voges, D.; Zimmermann, K. and Schilling, C. Biomechatronics is not just biomimetics� Robot Motion and Control (RoMoCo), IEEE (2013): 74–79. (2013)

Zec, M.; Uhlig, R. P.; Ziolkowski, M. and Brauer, H. Three-dimensional Numerical Investigations of Lorentz Force Eddy Current Testing� J.M.A. Rebello, F. Kojima und T. Chady: Electromagnetic Nondestructive Evaluation (XVI); IOS Press, Amsterdam, Berlin, Tokyo, Washington DC, 2014, S. 66-74. (2014)

Zeiser, R.; Ayub, S.; Berndt, M.; Müller, J. and Wilde, J. Failure mode analysis and optimization of assembled high temperature pressure sensors� 15th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE), 2014. Piscataway, NJ Vol. 2014 IEEE. (2014)

Zimmermann, K.; Fiedler, B.; Gerlach, E.; Husung, I.; Zeidis, I.; Füßl, R.; Manske, E.; Theska, R. and Hausotte, T. Positioning with nanometre precision requires a high tech Nanopositioning and Nanomeasuring Machine (NPMM) and an optimal machine setup� Shaping the future by engineering. Ilmenau Vol. 2014, pp. 16-17. Univ.-Verl. Ilmenau. (2014)

Brückner, S.; Döscher, H.; Kleinschmidt, P.; Supplie, O.; Dob-rich, A. and Hannappel, T. Verfahren zur Oberflächenpräparation von Si(100)-Substraten� (EU 12008516.2 – 1362) (2013)

Fischer, M.; Bartsch, H.; Hoffmann, M.; Müller, J.; Pawlowski, B. and Barth, S. Silicon ceramic composite substrate� (US 8391013 B2) (2013)

Patents

Venia Legendi & PhD / Doctorate Theses

Aguilera Mena, Jesús Jaime (2012) Dynamic weighing calibration method for liquid flowmeters. A new approach Process Measurement Technology Group

Alferenok, Artem (2013) Numerical simulation and optimization of the magnet system for Lorentz Force Velocimetry of low-conducting materials Electrothermal Energy Conversion Group

Ammon, Danny (2014) Intelligente elektronische Patientenakten� Entwurf und Anwendung eines Vorgehensmodells für die Entwicklung wissensbasierter Systeme zur Unterstützung medizinischer Dokumentationsprozesse Biosignal Processing Group

Arnold, Christian (2013) Entwicklung fuzzybasierter Leitkomponenten für das Klimamanagement in der präventiven Konservierung System Analysis Group

Bauer, Gerd (2014) EasyKit� Eine Entwicklungsmethodik für das Rapid Engineering miniaturisierter mechatronischer Systeme System Analysis Group

Bönicke, Holger (2013) Flexible und plattformunabhängige Entwicklung microcontrollerbasierter mechatronischer Systeme für Nutzer ohne Vorwissen System Analysis Group

Busch, Christian (2014) Ein Beitrag zum modellbasierten Regelungsentwurf elektropneumatischer Applikationen System Analysis Group

Degle, Michaela (2013) Evaluation von Veränderungen des Sehverhaltens mittels optometrischer Analyse- und Trainingsmethoden� Ein interdisziplinärer Ansatz in der Optometrie Biomedical Engineering Group

Deistung, Andreas (2013) Susceptibility weighted imaging and quantitative susceptibility mapping at 3 Tesla and beyond. New approaches and applications Biomedical Engineering Group

Dobermann, Dirk (2013) Stabilisierung der Bildlage abbildener optischer Systeme Precision Engineering Group

Dornbusch, Kay (2014) Einsatz von miniaturisierten Spektralsensoren für die Prozessanalytik von Flüssigphasenreaktionen in Mikrokanälen Micromechanical Systems Group

Contact


204




205



Eisenhardt, Anja (2013) Charakterisierung der elektronischen und chemischen Eigenschaften reiner polarer InN-Oberflächen und deren Beeinflussung durch Adsorbate Surface Physics and Functional Nanostructures Research Unit Engmann, Sebastian (2014) Spectroscopic ellipsometry study on the morphology of polymer fullerne solar cells Experimental Physics Group I

Erbe, Torsten (2013) Beitrag zur systematischen Aktor- und Aktorprinzipauswahl im Entwicklungsprozess Precision Engineering Group

Fiedler, Jan (2013) Elektrische und strukturelle Eigenschaften von supraleitenden Schichten in Gallium-implantiertem Silizium und Germanium Experimental Physics Group I

Figler, Thomas (2014) Entwicklung eines Getriebes mit hydrodynamischer Kupplung für Turboverbundaufladesysteme Automotive Engineering Group

Finck, Alexander von (2014) Table top system for angle resolved ligth scattering measurement Optical Engineering Group

Gattnar, Eva (2014) Generisches Modell zur standartisierten und automatisierten Erfassung von klinischen Prozessdurchlaufzeiten und Ereignissen durch hierarchische Clusterung und semantische Transformation Biomedical Engineering Group

Gebhardt, Stefan (2014) Entwurf und Realisierung eines kapazitiven Tomographie-Systems nach dem Dreielektroden-Messprinzip Advanced Electromagnetics Group

Granzner, Ralf (2013) Nanometer-MOSFETs für Digital- und Hochfrequenzanwendungen Solid-State Electronics Group

Grimm, Michael (2014) Dirty RF signal processing for mitigation of receiver front-end non-linearity Electronic Measurement Engineering Group

Gutjahr, Tobias (2013) Dynamic system identification with Gaussian processes in model-based engine development System Analysis Group

Halbleib, Andreas (2013) Methods for Time-Frequency-Space parameterization of the human visual system Biomedical Engineering Group

Haverkamp, Imke (2013) Systementwicklung und Optimierung eines hochempfindlichen digitalen Magnetfeldsensors Advanced Electromagnetics Group

Heinrich, Gerrit (2014) Direkte Laserablation von dünnen, auf Silizium abgeschiedenen Siliziumnitridschichten durch nichtlineare Absorption Experimental Physics Group I

Heppe, John (2013) Konstruktion sensorisierter Textilien für die biomedizinische Technik Biomechatronics Group

Hesse, Tobias Wilhelm (2014) Predictive forcefield trajectory planning for automated vehicles Mechatronics Group

Hofer, Manuel (2014) Atto- to zeptogram mass sensors Micro- and nanoelectronic Systems Group

Hofmann, Meike (2013) Opto-fluidische Mikrosysteme zur Partikelanalyse Optical Engineering Group

Humbla, Stefan (2014) Entwurf und Umsetzung eines rekonfigurierbaren Schaltmatrix-Satelliten-Experiments zum Nachweis der Raumfahrttauglichkeit keramischer Mikrowellenschaltungstechnologie Group for RF and Microwave Research

Jahr, Norbert (2014) Herstellung und Charakterisierung neuartiger Hybridnanostrukturen für bioanalytische Anwendungen Process Measurement Technology Group

Jiménez López, Omar Eduardo (2014) Development of biomechatronic devices for measurement of wrenches occurring in animal and human prehension Biomechatronics Group

Kopfstedt, Thomas (2014) Algorithms for planned and coordinated movement of formations of mobile systems System Analysis Group

Kühnel, Michael (2013) Rückführbare Messung der mechanischen Eigenschaften von Federkörpern für die Kraftmesstechnik Process Measurement Technology Group

Lilienthal, Katharina (2014) Nanostrukturierte SiO 2 -Gläser für die Mikrotechnik und Biosensorik Nano-Biosystems Engineering Group

Lübbers, Benedikt (2013) AlGaN-based pH-sensors. Impedance characterisation, optimisation and application for foetal blood sampling Nanotechnology Group

Luhn, Thomas (2013) Prozessdiagnose und Prozessüberwachung beim Rührreibschweißen Production Technology Group

Malsch, Danièll (2014) Strömungsphänomene der tropfenbasierten Mikrofluidik Group for Physical Chemistry / Microreaction Technology

Muhsin, Burhan (2014) Reproduzierbar effiziente Prozessierungvon flexiblen Polymersolarmodulen Experimental Physics Group I

Nguyen, Tran Trung (2014) Entwicklung eines optischen Multi-Lasertracker-Systems zur berührungslosen Positionsbestimmung in kinematischen Systemen System Analysis Group

Oeder, Andreas (2013) System design of optical trapping setups Optical Engineering Group

Petković, Bojana (2013) Assessment of linear inverse Problems in magnetocardiography and Lorentz Force eddy current testing Biomedical Engineering Group

Plentz, Jonathan (2013) Laserkristallisierte multikristalline Silicium-Dünnschicht-Solarzellen auf Glas Experimental Physics Group I

Polster, Tobias (2014) Aluminiumnitrid Dünnschichtmembranen. Charakterisierung und technologische Integration in den MEMS-Prozessfluss Micromechanical Systems Group

Popugaev, Alexander E. (2014) Miniaturisierte Mikrostreifenleitungs-Schaltungen bestehend aus zusammengesetzten Viertelkreisringen Group for RF and Microwave Research

Rahneberg, Ilko (2013) Untersuchungen zu optischen Mehrkomponentenmesssystemen Process Measurement Technology Group

Ramsperger, Marcel (2014) Entwurf einer aktiven Ventil-Regler-Einheit für den Betrieb mit gasförmigem Wasserstoff bis 87,5 MPa zum Einsatz in Brennstoffzellen-Fahrzeugen Mechatronics Group

Renjewski, Daniel (2013) An engineering contribution to human gait biomechanics Biomechatronics Group

Renner, Franziska (2014) Benchmark-Experiment zur Verifikation von Strahlungstransportrechnungen für die Dosimetrie in der Strahlentherapie Biomedical Engineering Group

Richter, Johannes (2014) Entwicklung einer Prozessregelung für das atmosphärische Plasmaspritzen zur Kompensation elektrodenverschleißbedingter Effekte Production Technology Group

Rösch, Roland (2013) Einfluss der Elektroden auf die Stabilität von Polymersolarzellen Experimental Physics Group I

Rzesanke, Daniel (2013) Laborexperimente zum Einfluss elektrischer Ladungen auf Wolkenprozesse Experimental Physics Group II

Sakalauskas, Egidijus (2012) Optical properties of wurtzite InN and related alloys Experimental Physics Group I

Schreiber, Jan-Michael (2014) Plausibility Tracking. A method to evaluate anatomical connectivity and microstructural properties along fiber pathways Biomedical Engineering Group

Schütze, Christina (2013) Synthese und Funktionalisierung von Fulleren C 60 und seinen Derivaten für die Anwendung in biologischen Systemen Chemistry Group

Schwarzer, Steffen (2013) Optimierung der Auslegung und des Betriebsverhaltens von hohlradgetriebenen Innenzahnradpumpen Automotive Engineering Group

Selva Ginani, Luciano (2013) Optical scanning sensor system with submicron resolution Precision Engineering Group

Serebryakova, Elena (2013) High-power comb-line filter architectures for switched-mode RF power amplifier systems Group for RF and Microwave Research

Singh, Chetan Raj (2013) Correlation of charge transport with structural properties in poly3-hexylthiophene-polyperyleneacrylate block copolymers and its ilmplication on solar cell performance Experimental Physics Group I

Steffanson, Marek (2013) Entwicklung eines ungekühlten Infrarotdetektors basierend auf einem neuartigen thermomechanischen Mikrosensor Micro- and nanoelectronic Systems Group

Taubmann, Peter (2013) Analyse der Ventilfederbewegungen als Beitrag zur Beeinflussung der Verschleißursachen an den Auflageflächen Machine Elements Group

Taubmann, Rebekka (2013) Untersuchungen zur Erweiterung der thermogravimetrischen Messung mit Magnetschwebewaage für die Differenzthermoanalyse durch Einführung einer stabilen rotationsfreien magnetischen Lagerung Mechatronics Group

Turkovic, Vida (2014) Long-term stabilization of organic solar cells using additives Group Technical Physics

Volkert, Ralf (2014) Regelung der Luftspaltlänge von Elektromagneten für Nanopositioniersysteme mit magnetischer Führung Mechatronics Group

Weidauer, Thomas (2013) Numerical investigations of shallow moist convection Group for Theoretical Physics II / Computational Physics

Werner, Michael (2013) Design, Optimierung, Realisierung und Test von passiven Magnetsystemen für die Lorentzkraftanemometrie an Elektrolyten Group for Inorganic-Nonmetallic Materials

Zec, Mladen (2013) Theory and numerical modelling of Lorentz force eddy current testing Advanced Electromagnetics Group

Contact


206



Science makes people reach selflessly for truth and objectivity; it teaches people to accept reality, with

wonder and admiration, not to mention the deep awe and joy that the natural order of things brings to the

true scientist�

Lise Meitner

Your notes

center of micro

Documents