university of limericksymposia.microscopy.ie/msi2015/doc/msi2015.pdf · dr. david cottell, retired...

The Microscopy Society of Ireland’s 39th Annual Symposium

26th – 28th August 2015

University of Limerick

MSI2015 I University of Limerick, Limerick, 26th-28th August 2015

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This meeting has been sponsored by the following companies and institutes whose support is greatly appreciated.

Gold Sponsors

Silver Sponsors

Bronze Sponsors

EBSD workshop sponsor


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Microscopical Society of Ireland Committee

President: Mr. Alexander Black, Anatomy, NUI-Galway.

Secretary: Dr. Kerry Thompson, Centre for Microscopy and Imaging, Anatomy, NUI Galway, Ireland.

Treasurer: Ms. Tiina O'Neill, Imaging Facility, Conway Institute, UCD.

Postgraduate representative: Robert O'Connell, CRANN and School of Physics, Dublin City University.

Postgraduate representative: Sarah Martyn, Dublin City University.

Committee Members:

Prof. Fiona Lyng, FOCAS Institute, Dublin Institute of Technology, Kevin St., Dublin. Prof. Dmitri Papkovsky, Department of Biochemistry, University College Cork.

Dr. Hongzhou Zhang, CRANN and School of Physics, Trinity College Dublin. Dr. Thomas Flanagan, School of Medicine & Medical Science , UCD. Dr. Gerard Brennan, School of Biology, Queen's University Belfast.

Dr. Tatiana Perova, Department of Electronic Engineering, TCD. Prof. Ursel Bangert, Department of Physics and Energy, University of Limerick.

Dr. Yina Guo, Materials & Surface Science Institute, University of Limerick. Dr. Andrew Stewart, Department of Physics and Energy, University of Limerick.

Dr. Danny Fox, CRANN and School of Physics, TCD. Prof. Martin Steer, Retired from School of Biology & Environmental Science, UCD.

Dr. David Cottell, Retired from Electron Microscopy Laboratory, Agriculture & Food Science Centre, UCD.

Local Organising Committee:

Prof. Ursel Bangert, Department of Physics and Energy, University of Limerick. Dr. Yina Guo, Materials & Surface Science Institute, University of Limerick.

Mr. Eoghan O’Connell, Department of Physics and Energy, University of Limerick. Dr. Andrew Stewart, Department of Physics and Energy, University of Limerick.

Webpage:

http://www.microscopy.ie/

http://physics.tcd.ie/ultramicroscopy/staff/robert/

http://www.microscopy.ie/


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General Information

Symposium Location: All lectures are being held in the Lecture theatre in the Analog Devices building on the 2nd floor. Trade exhibition and Posters are located on the ground floor of the Analog Devices Building.

Wifi connection: Choose “ulwireless” from your WIFI setting, no password needed.

Pre-conference workshop (EBSD workshop) Location: EBSD workshop is held in the lower ground floor, Room MSB-012, Materials & Surface Science Institute (building 18 in the map). Due to the construction work, visitors have to enter through Lonsdale building (building 17 in the map). Posters: Poster sessions will be held during the symposium on the ground floor of Analog Devices building. It is requested that all who are presenting posters be in attendance at the times detailed in the symposium schedule. Exhibitors: Exhibition stands will be held during the symposium on the ground floor of Analog Devices building.

Prizes: Prizes will be awarded at the conference for the following:

• The best student oral presentation in the materials sciences • The best student oral presentation in the biological sciences

• The best student poster presentation in the materials sciences

• The best student poster presentation in the biological sciences

Winners will be announced at the end of the conference. Conference dinner: The conference dinner will be held in the Pavilion restaurant on Thursday the 27th Aug.

http://www.google.ie/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRxqFQoTCL3ZgNnOq8cCFYPSGgodzg4FVA&url=http://eurothermseminar102.com/venue/&ei=GnfPVb3kHoOla86dlKAF&bvm=bv.99804247,d.ZGU&psig=AFQjCNHbBZsNNvOA-FhH_iRZ2OegfEgHZQ&ust=1439746123661483


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Campus Map

Important locations:

16, University centre

17, Lonsdale building

18, Materials & Surface Science Building (MSSI)

22, Sports Centre

32, Cappavilla Student Village


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Analog Devices Building

Pavilion Restaurant

http://www.doconnor.ie/project/sports-pavilion-university-of-limerick/


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Wifi connection: ulwireless Programme

Wednesday, 26/8/2015 EBSD workshop (Materials & Surface Science Institute)

9:00 to 9:40 Keith Dicks, Oxford Instruments

Introduction to EBSD and the sample preparation method

9:40 to 10:10 Maarten Nijland, Veco B.V Local epitaxial growth made visible

10:10-10:30 COFFEE BREAK

10:30-11:00 Norbert Schäfer, Helmholtz Zentrum Berlin für Materialien und Energie GmbH

Assessing strain in CuInSe2 thin films by means of electron backscatter diffraction, X-ray diffraction techniques, and Raman microspectroscopy

11:00- 11:30 Yina Guo, University of Limerick Texture analysis in linear friction welded Ti6Al4V alloys

11:30-12:00 Keith Dicks, Oxford Instruments

Introduction to tEBSD

12:00-13:00 LUNCH

13:00-14:10 Demonstration in the microscope, Group 1



16:30 CLOSE OF WORKSHOP

Wednesday, 26/8/2015 MSI symposium (Analog Devices Building)

14:30-16:30 Arrival and Registration-Ground floor, Analog Devices building Poster Setup

16:45 Welcome

16:50-17:30 Keynote: John Rodenburg, University of Sheffield

Sponsored by Light, X-ray and Electron Ptychography

17:30-19:00 Poster session

Thursday, 27/8/2015

Session I Chair: Dr. Ramesh Raghavendra 9:00- 9:30 Invited: Kieran.Mcdermott, University of Limerick Light Microscopy with Application to Biology

9:30-9:45 M.J. Leahy, National University of Ireland Galway Advances in Optical Coherence Tomography


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9:45-10:00 Mahendar Kumbham, University of Limerick Phase retrieval, deconvolution, and resolution in coherent optical microscopy

10:00-10:15 Katie-Jo Harwood, Ulster University

The Development of Plasma Modified Electrospun Poly (L-Lactide-Co D, L-Lactide) Matrices for the Treatment of Corneal Scarring Contributed talks

10:15-10:30 Trade speaker: Calum Dickinson, JEOL SXES: A new detector for Li to U and chemical state analysis in SEM


Session II Chair: Prof. Martin Steer 11:00-11-30 Invited: Ramesh Raghavendra, Waterford Institute of Technology

X-ray Tomography

11:30-11:45 Andrew Stewart, University of Limerick Diffraction tomography and its applications’

11:45-12:00 Trade speaker: Chris Stephens, Thermofisher Advances in High Resolution Microanalysis’

12:00-12:15 Fengshi Yin, University of Limerick Precipitates in 9-12%Cr ferritic/martensitic heat-resistant steels’

12:15-12:30 Aleksey Shmeliov, Trinity College Dublin Identification of monolayers and stacking sequences in 2D nanostructures

12:30-14:00 LUNCH

Session III Chair: Prof. Hongzhou Zhang 14:00-14:30 Invited: Ning Liu, University of Limerick

Light Microscopy

14:30-14:45 Maria O’Brien, Trinity College Dublin Low Frequency Raman Spectroscopy of Two-Dimensional Materials

14:45-15:00 Trade speaker: Michael Flynn, Analog Devices Failure Identification – Microscopy to the Rescue 15:00-15:15 J. Cookman, University College Dublin TEM Tomography of Anisotropic Gold Nanoparticles to Develop a Novel

Method for Acquiring Numerical Parameters

15:15-15:30 Shalini Singh, University of Limerick ‘Colloidal Cu2ZnSn(SSe)4 (CZTSSe) Nanocrystals- Shape and Crystal Phase

control to form Dots, Arrows, Ellipsoids and Rods



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Session IV Chair: Dr. Ning Liu 16:00-16:30 Invited: Lekshmi Kailas, University of Limerick

Simultaneous High Resolution Imaging of Electrical, Chemical and Mechanical Properties of Surfaces and Interfaces

16:30-16:45 Yangbo Zhou, Trinity College Dublin ‘Controllable doping in graphene and erasable electronic devices by electron beam irradiation’

16:45-17:00 Hannah C Nerl, Trinity College Dublin STEM EELS Analysis of 2D Layered Inorganic Materials at Atomic Resolution

17:00-17:15 Noel P O’Dowd, University of Limerick Application of electron back scattered diffraction to validate a crystal plasticity constitutive model of a structural steel

17:15-17:30 Trade speaker: Chuan Wei Chung, Bruker Applications of Bruker Four Channel Annular SDD

17:30-19:00 Poster session (AGM of the MSI starting at 18:30)

19:30-23:00 Conference Dinner (Pavilion)

Friday, 28/8/2015

Session V Chair: Prof. Ursel Bangert 10:00-10:30 Invited: Hongzhou Zhang, Trinity College Dublin He-Ion Microscopy

10:30-10:45 Pierce Maguire, Trinity College Dublin Ne+, He+ and Ga+ Irradiation for Nanometre Tuning of 2D Materials

10:45-11:00 Trade speaker: Jan Ringnalda, FEI Understanding structure-property relationships in nanomaterials by in situ transmission electron microscopy

11:00-11:15 Satbir Kaur Gill, National University of Ireland Galway Differential staining of ECM produced by the murine stromal cells



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11:45-12:00 Marc A. Fernandez-Yague, National University of Ireland Galway Piezoresponse (PFM) and Transmission Electron Microscopy (TEM) study of Boron Nitride

12:00-12:15 Dalibor Soukup, Keele University Magnetic Nanoparticle Interactions with Biological Systems - Non-Invasive Monitoring

12:15-12:55 Keynote: Odile Stéphan, Laboratoire de Physique des Solides, Université Paris Sud

Sponsored by Aberration-Corrected STEM Imaging, Spectroscopy and Cathodoluminescence

13:00 Prizes and symposium end


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Keynote Speaker Biographical Information

Prof John Rodenburg

John Rodenburg undertook his PhD in the Cavendish Laboratory, University of

Cambridge. He remained in Cambridge as a Royal Society Research Fellow, before

moving to the Materials and Engineering Research Institute at Sheffield Hallam

University as a Research Professor. In 2003 he moved to the Electronics and

Electrical Engineering Department in the University of Sheffield. His main research

interest is in phase retrieval (or 'lensless') microscopy, particularly ptychography,

which he developed in its present form over the last 25 years over all wavelengths

(light, X-ray and electron). Other interests have included detector development in

electron microscopy and applications of EM and other structural analysis

techniques to various materials systems. He has founded two companies, one of which - Phase Focus - is

using ptychography to deliver novel imaging techniques in a variety of fields including contact lens

metrology and cell growth life-cycle analysis.

Prof Odile Stéphan

Prof Odile Stéphan is a Professor of physics at University Paris-Sud and an

honorary member of the Institut Universitaire de France. She is currently

leading the STEM group at the Orsay Solid State Physics Laboratory.

Her research interests span from growth mechanisms to optical and

electronic properties of various nanostructures and nanomaterials. She

focuses on the development and the use of Electron Energy-Loss

Spectroscopy and derived innovative spectroscopies to probe at the

nanometer scale the structural electronic and optical properties of original

nanostructures like nanotubes and related nanostructures (C and hybrids), nanophotonics objects,

molecular magnets or oxide heterostructures and to explore new physics phenomena at low dimensions

(plasmon coupling, electron magnetic field confinement and exaltation). She has pioneered the use of

EELS on nanotubes to demonstrate heteroatom segregation effects and capillarity driven coating effects

in these nanostructures. More recently, she has shown that EELS can be used as an alternative to

photonic techniques to probe the optical properties of individual semi-conducting nanotubes and

plasmonic nanostructures with unprecedented spatial resolution. She has authored more than 150

publications, including 100 original articles in regular journals.


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Invited Speaker biographical information

Dr Lekshmi Kailas

Dr Lekshmi Kailas did her M.Sc. in Physics from the University of Kerala

(India) and PhD in Materials Physics from Universite Catholique de Louvain

(Belgium). Her thesis dealt with self-assembly of ultra-thin polymer films

and their surface and interface characterization, using various analytical

techniques including AFM, ToFSIMS, NanoSIMS, XPS etc. Lekshmi did her

post-doctoral projects at the University of Sheffield in polymer

crystallization studies (Dept. of Physics & Astronomy and Dept. of Chemistry), instrument development

for video rate AFM (Dept. of Physics & Astronomy) and cryo-TEM studies of spore surfaces (Dept. of

Molecular Biology and Biotechnology). She worked with the Department of Atomic Energy, Govt. of India

as a visiting scientist at the Indira Gandhi Centre for Atomic Research, before joining University of

Limerick as an instrument scientist at MSSI.

Dr Ramesh Raghavendra

Dr Ramesh Raghavendra holds a Ph.D from University of Twente, The Netherlands

and an MBA from Ireland. He worked as Senior Research Fellow in University of

Limerick for five years, then worked as Senior Materials Technologist for a

multinational company (Littelfuse) Dundalk for over 10 years prior to joining SEAM-

WIT in May 2008. He is currently Centre Director for SEAM.

His research background is in the areas of functional ceramics, glass and glass-

ceramics, sintering of powder materials and possesses significant expertise in

microwave and nano technologies. He holds patent in microwave processing of

ceramic materials and in cofiring of ceramics. In addition he has submitted numerous invention

disclosures. He has also authored/co-authored more than 55 refereed journal publications.

In his present role as Centre Director of SEAM, Ramesh has been instrumental in establishing

collaborations with over 100 Irish based industries and successfully managed to deliver over 800 directly

funded Industrial projects (short, medium and long term). Furthermore, he is currently a Project

Coordinator for EU funded FP7-SME project. Through these and state supported projects, Ramesh has

secured over 7.5 million euros in funding for SEAM-WIT. In recognition of the industrial impact SEAM

created under his leadership, Ramesh received KTI (Knowledge Transfer Ireland) Award 2015.

Dr Ning Liu

Dr Ning Liu received a B.S. degree in Physics from Peking University, China, in

1999 and a Ph.D. degree in Physics from University of California at Irvine, USA

in 2005. Prior to joining the University of Limerick，Ireland as a lecturer in

2013, she worked as postdoctoral research fellow in UK, Canada, China, and

Ireland. She has specialties in scanning probe microscopy and ultrafast

spectroscopy and microscopy. Her current research interests focus on

nanophotonics and plasmonics.


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Prof Hongzhou Zhang Prof Hongzhou Zhang received his PhD in Applied Physics at Rice University (US)

in 1999. He is a SFI Stokes Lecturer at the School of Physics, Trinity College and

a Principal Investigator at CRANN (the Centre for Research on Adaptive

Nanostructures and Nanodevices). He has published more than 100 peer-

reviewed papers in physics and nanoscience, mostly in high impact journals

(e.g., Applied Physics Letters, Advanced Materials, Nanoletters, Nanoscale,

Small, etc.), with a total citation count of over 3500. He has an h-index of 27

(Web of Science) and a RG score of 38.86 (Researchgate.net) and two

patents. Prof Zhang has delivered over 20 invited talks at international conferences and departmental

seminars. He currently has a research group of two postdocs and five postgraduate students. He is a

pioneering researcher in the field of helium-ion microscopy (HIM) and his research group is focused on

understanding He+-matter interaction with one/two-dimension materials in terms of signal

generation/detection for imaging mechanism and structural modification for nanofabrication.

Prof Kieran McDermott

Prof Kieran McDermott is the Professor of Anatomy and Head of Teaching and

Research in Anatomy at the Graduate Entry Medical School, University of Limerick.

He received a BSc (Hons) in Zoology from University College Cork, an MSc in

Experimental Pathology and Toxicology from the Royal Postgraduate Medical

School at Hammersmith Hospital, London and undertook a PhD in Developmental

Neurobiology in the Department of Neuropathology in the Institute of Psychiatry,

Denmark Hill, London. Postdoctoral work in developmental neurobiology, funded

by a Wellcome Trust Travelling Fellowship, was subsequently undertaken at the

Department of Anatomy and Cell Biology, Emory University, Atlanta, USA and later

in experimental neuropathology at the Department of Clinical Veterinary Medicine, Cambridge, UK. He

was subsequently appointed Lecturer in the Department of Anatomy at University College, Cork (UCC)

where he remained until moving to the University of Limerick in 2014. He was a Principal Investigator in

the UCC’c Biosciences Institute since its foundation in 2002 and Director of the BioSciences Imaging

Centre from 2007-2014. In 2003, he jointly won the Olympus-GIT Verlag International Microscopy Award

and, in 2006, he received a UCC President’s Award for Research on Innovative Forms of Teaching and

Learning (2006). Images from his research won the Anatomical Society Best Image Award July 2012 and

also received an honourable Mention in the Olympus Bioscapes Competition in 2012. He became the first

elected President of Neuroscience Ireland, Ireland’s new national neuroscience association in 2006,

serving a three year term. His research interests include the developmental origins and lineage

determinants of neural cell types, the vulnerability of nervous system development to intrinsic and

extrinsic perturbation and the pathophysiology of neurodegenerative diseases such as Parkinson’s disease

and multiple sclerosis. He has received research funding from the European Union (EU), Science

Foundation Ireland, Health Research Board of Ireland, Wellcome Trust, Programme for Research in Third

level Institutions, Irish Research Council, Anatomical Society and the Multiple Sclerosis Society. He was

elected to the Council of the Anatomical Society in 2012 and awarded the prestigious Fellowship of the

Anatomical Society in 2013.


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Dr Maarten Nijland

Dr. Maarten Nijland was born in Hellendoorn, the Netherlands, and studied

Chemical Engineering at the university of Twente. He received the

designation 'cum laude' with both his BSc. and MSc. degree, where he

specialized in Chemistry and Technology of Materials for his masters. For his

MSc. thesis, he worked in the Inorganic Materials Science group on polymer-

assisted deposition of SrRuO3 thin films. For this work, he received the

Golden Master Award 2010 from the Royal Dutch Chemical Society (KNCV),

as well as the graduation prize from the faculty of science and technology.

From August 2010 to November 2014, he worked as a PhD candidate in the Inorganic Materials Science

group under the supervision of prof. dr. ir. André ten Elshof, prof. dr. ing. Guus Rijnders and prof. dr. ir.

Gertjan Koster. He studied novel routes for patterning epitaxial perovskites made by pulsed laser

deposition (PLD). His PhD thesis is entitled "Anisotropy in Patterned Perovskite Oxides". Since March 2015

he is working as application engineer in a company making precision metals, mainly by using

electroforming technology.

Norbert Schäfer

Norbert Schäfer received his diploma in Materials Science from the Unversity of

Stuttgart (Germany). He wrote his diploma thesis at the department of Prof.

Mittemeijer (Phase Transformations, Thermodynamics and Kinetics) at the Max

Planck Institute for Intelligent Systems. His thesis, entitled "Orientation

relationships in iron-carbonitride layers", dealt with the fabrication and

characterisation of surfacial compound layers on ferrite substrates using EBSD and

XRD as main analytical techniques. Currently he is a Ph.D. student at the Institute

Nano-architectures for Energy Conversion at the Helmholtz Zentrum Berlin für

Materialien und Energie, Berlin. His research deals with the microstructural

characterisation of chalcopyrite thin-film solar cells by means of EBSD, L-EBIC, Raman spectroscopy as

well as different XRD techniques.


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INVITED

Local epitaxial growth made visible (EBSD workshop)

Maarten Nijland1, Sean Thomas2, Mark A. Smithers1, Nirupam Banerjee1, Dave H. A. Blank1, Guus Rijnders1, Jing Xia2, Gertjan Koster1, and Johan E. ten Elshof1

1, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE , Enschede , The

Netherlands 2, Department of Physics and Astronomy, University of California, 4129 Frederick Reines Hall , Irvine , CA

92697-4575 , USA

With pulsed laser deposition, epitaxial thin films can be deposited onto single crystalline

substrates with an unsurpassed degree of control on the atomic scale. Although essential to

obtain films of the highest possible quality, single crystalline substrates also limit the films to just

a single orientation, reducing the degrees of freedom in designing materials with advanced local

functionalities. To control the orientation on smaller scale, we patterned layers of inorganic

nanosheets onto arbitrary substrates and used the well-defined crystal structures of the

nanosheets as a basis for epitaxial growth of functional perovskite oxide materials. Proving

epitaxy on these kinds of samples is more challenging than on single crystalline substrates, since

the random in-plane orientations of the crystallites limit structural analysis by XRD. Using a Zeiss

MERLIN™ SEM, we show that EBSD is a powerful tool to locally visualize the orientation of such

complex oxide films and prove epitaxy on the scale of individual nanosheets.


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Assessing strain in CuInSe2 thin films by means of electron backscatter diffraction, X-ray

diffraction techniques, and Raman microspectroscopy (EBSD workshop)

N. Schäfer1, A.J. Wilkinson2, T. Schmid3, T. Schulli4, G.A. Chahine4, J. Marquardt1,5, S. Schorr1,5, A. Winkelmann6, M. Klaus1, C. Genzel1, T. Rissom1, D. Abou-Ras1

1. Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin,

Germany 2. Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, U.K.

3. Federal Institute for Materials Research and Testing, Richard-Willstätter-Str.11, 12205 Berlin, Germany 4. European Synchrotron Radiation Facility, BP 220, Grenoble Cedex, France

5. Freie Universitaet Berlin, Institute of Geological Sciences, Malteserstr. 74-100, 12249 Berlin, Germany 6. Bruker Nano GmbH, D-12489 Berlin, Germany

Chalcopyrite-type solar cells based on Cu(In,Ga)Se2 absorber layers have shown power-

conversion efficiencies up to 21.7 % on glass substrates [1]. The understanding of structure-

property relationships of Cu(In,Ga)Se2 absorber layers is crucial to enhance the performance of

the complete device. Grain boundaries have shown to influence the optoelectronic properties

partially [2-4]. Extended structural defects within individual grains, which are connected with

microstrain, have been studied in the past and might influence i.e. recombination of charge

carriers [5-8]. Since quaternary Cu(In,Ga)Se2 absorber layers exhibit substantial chemical

gradients and grain sizes depending on the final chemical composition, ternary CuInSe2 thin films

with an average grain sizes of more than 1 μm were used for a first study. High-resolution EBSD,

X-ray microdiffraction techniques and Raman microspectroscopy are able to resolve strain within

individual CuInSe2 grains. It is the aim to correlate the local strain distributions in CuInSe2 thin

films to the optoelectronic properties of the corresponding solar cells obtained by means of

electron-beam-induced current and cathodoluminescence measurements.

References: 1. P. Jackson et al., Phys. Status Solidi RRL 9, No. 1 (2015). 2. M. Nichterwitz et al., Thin Solid Films 517 (2009) 2554–2557. 3. J. Kavalakkatt et al, J. Appl. Phys. 115, 014504 (2014). 4. M. Müller et al. J. Appl. Phys. 115, 023514 (2014). 5. J. Dietrich et al. , IEEE JOURNAL OF PHOTOVOLTAICS, VOL. 2, NO. 3, JULY 2012. 6. N. Schäfer et al., submitted to Acta Materialia 2015. 7. J. Dietrich et al., J. Appl. Phys. 115, 103507 (2014). 8. C. J. Kiely et al., Philosophical Magazine A, 63:6, 1249-1273.


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Light, X-ray and Electron Ptychography’ (keynote)

John Rodenburg

University of Sheffield

The word ‘ptychography’ (pronounced with a silent ‘p’) comes from the Greek ‘ptycho’ which

means ‘to fold’. Walter Hoppe, who first postulated the method in 1969 in the context of

electron crystallography, derived the word from the German ‘Faltung’, also meaning to fold, but

used in physics to mean ‘convolution’. The concept is to illuminate a crystal with a very confined

field of radiation (of the order of the size of the unit cell): now the diffraction peaks become

convolved with the Fourier transform of the illumination function, allowing them to interfere

coherently with one another. If the illumination is moved by less than a unit cell, and a second

diffraction pattern is recorded, then it turns out that there is enough information to solve for the

phase of all the diffraction beams, thus solving the long-standing ‘phase problem’ and allowing

us to image and object from its diffraction pattern alone.

The practical implementation of modern ptychography bears little relationship to this original

idea, but it still uses the same fundamental concepts – recording multiple diffraction patterns

using narrow and moving illumination. Extending the idea to continuous objects and deriving

effective computational inversion methods to process ptychographical data took many years.

However, it is now used very widely in X-ray imaging and high-resolution X-ray tomography, it

has found commercial application in light microscopy, and is beginning to make inroads into

electron microscopy.

Ptychography has potentially huge imaging benefits over all the wavelengths used for

microscopy: it is immune to lens aberrations (it does not even need a lens), it provides a perfect

modulus and phase image, it can be extended to 3D imaging and can remove multiple scattering

effects. The phase image (which can contain hundreds of phase wraps but can be measured very

sensitively) is ideal for unstained, unlabelled live cell imaging and has many potential applications

in electron microscopy. The removal and/or measurement of incoherent states, either in the

instrumentation or specimen – made possible by the data redundancy in ptychography – also

offers intriguing imaging possibilities.


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Investigating spinal cord development using confocal and two-photon microscopy

Kieran W. McDermott1,2 and Janelle M. Pakan1

1. Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland 2. Graduate Entry Medical School, University of Limerick, Limerick, Ireland

The mammalian central nervous system (CNS) develops from multipotent progenitor cells, which

proliferate and differentiate into the various cell types of the brain and spinal cord. Despite the

wealth of knowledge resulting from in vitro cell culture studies, there is a significant lack of

understanding of dynamic progenitor cell behaviour over the course of development. In order to

investigate cellular behaviour under physiologically relevant conditions we have developed an ex

vivo model system of the developing rat spinal cord. This method allows us to directly observe

specific populations of cells ex vivo in real time and over extended developmental periods as

cells undergo proliferation, migration and differentiation in the CNS. Previous investigations of

progenitor cell behaviour have been limited in either spatial or temporal resolution (or both);

this has previously been a necessity in order to preserve tissue viability and avoid phototoxic

effects of fluorescent imaging. Using two-photon and confocal microscopy and transfected

organotypic spinal cord slice cultures we have undertaken detailed imaging of a unique

population of neural progenitors, radial glial cells. This method uniquely enables analysis of large

populations as well as individual cells; ultimately resulting in a 4D dataset of progenitor cell

behaviour for up to 7 days during embryonic development. This approach can be adapted to

study various tissues during development and a variety of cell populations can be targeted using

appropriate promoter driven fluorescent protein expression. Beyond the observation of cell

behaviour under normal conditions, this approach also allows for the manipulation of

developmental processes with pharmacological and genetic techniques; the ability to control the

tissue microenvironment makes this ex vivo model system a powerful tool to elucidate the

underlying molecular mechanisms regulating cell behaviour during embryonic development.

Keywords: progenitor cells, spinal cord, two-photon microscopy, organotypic culture


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Principles and Applications of X-ray Micro-Tomography

Ramesh Raghavendra

SEAM Research Centre, Waterford Institute of Technology, Waterford

X-ray micro-tomography (XMT) is a non-destructive 3D imaging and measurement technique that

is increasingly being used by academic researchers and development engineers for wide ranging

applications. The technique, which creates a 3D map of x-ray attenuation of the scanned

material, allows the quantification of defects (such as cracks, voids, foreign particles or

inclusions), co-ordinate measurement, actual/nominal comparisons with CAD designs and

reverse engineering. SEAM has vast experience in utilising this technique for wide ranging

industrial sectors. The principles of the technique, applications and few case studies are

presented. The vast number of examples presented reflects the multidisciplinary use of the X-ray

tomography equipment.


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Transient absorption imaging versus super-resolution optical microscopy

Christophe Silien,1 Ning Liu,1 Aladin Mani,2 Susan Daly,1 Mahendar Kumbham,1 Kevin O’Dwyer,1

Paolo Bianchini,3 Alberto Diaspro,3 Syed. M. Tofail,1 André Peremans2

1. Department of Physics & Energy, and Materials and Surface Science Institute (MSSI), University of Limerick, Limerick, Ireland

2. LaserSpec, Malonne, Belgium 3. Nanoscopy, Istituto Italiano di Tecnologia (IIT), Genoa, Italy

In the context of the optical probing of materials, transient absorption (TA) spectroscopy reveals

critical information on the dynamics of excited states with time resolution below pico- and

femtosecond. TA is widely used to study the optical properties and dynamics in semiconductors,

metals as well as inorganic and organic pigments and photovoltaic dyes. At mid-infrared

wavelengths, TA typically probes vibrational transitions and is used for example to study the

folding of biological macromolecules. When implemented in an optical microscope the spatial

resolution of TA signal maps remains however limited by diffraction. Thus although isolated

nanoscale objects can be analyzed in terms of sensitivity, heterogeneity in samples at the same

length scale remains unresolved. Our group is involved in developing strategies to overcome the

so-called Abbe limit for TA imaging. In this talk, we will review the various strategies that are

available and discuss the recent advances in the field made possible by exploiting the photo-

physics of the specimens.

Acknowledgements: The LANIR research leading to these results has received funding from the

European Community's Seventh Framework Programme (FP7/2012-2015) under grant

agreement n°280804. This communication reflects the views only of the authors, and the

Commission cannot be held responsible for any use which may be made of the information

contained therein. This research was also supported by Science Foundation Ireland

(13/TIDA/I2613). M.K. acknowledges funding from the Integrated Nanoscience Platform for

Ireland (INSPIRE), initiated by the Higher Education Authority in Ireland within the PRTLI5

framework. K.O.D. acknowledges a postgraduate scholarship from the Irish Research Council. A.P.

is a Research Director of the Belgian Fund for Scientific Research (FNRS-FRS).


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Simultaneous High Resolution Imaging of Electrical, Chemical and Mechanical Properties of

Surfaces and Interfaces

Lekshmi Kailas

Materials and Surface Science Institute, University of Limerick

One of the most common and frustrating problems researchers face while working with ‘soft’-

‘hard’ systems or interfaces is the difficulty in simultaneously imaging ‘soft’ materials (eg.

biological species) and relatively harder materials (e.g. a metallic or polymeric medical devices)

as well as obtaining information about the material properties at the nanoscale. In order to

study such systems and extract information about their physical, chemical, electrical and

mechanical properties, the use of hybrid instruments where one or more characterization

techniques can be simultaneously applied would be extremely useful. This talk will focus on

investigating surfaces and interfaces using a hybrid nanoscope that combines electrical modes of

scanning probe microscopy with confocal laser scanning microscopy, scanning near-field optical

microscopy and Raman spectroscopy.


21

Helium Ion Microscopy

Hongzhou Zhang

School of Physics and CRANN, Trinity College Dublin, Dublin 2, Ireland

Breakthroughs in characterisation and fabrication technologies (e.g., scanning tunnelling

microscopy (STM) and electron beam lithography (EBL)) have enabled rapid and profound

advancements in many fields of natural sciences. Mirroring these breakthroughs, the recently-

developed helium-ion microscopy (HIM) is set to become a key enabling technology for the

future of nanoscience. Particularly, the ultrafine helium-ion beam in the HIM offers great

potential in sub-nanometre gentle patterning, and therefore meets the requirements of

fabrication of novel nano functional blocks, which demand finer structuring capability with

higher precision than the currently available methods. In this talk, we will first briefly introduce

some fundamentals of the new technology, discussing its strength and weakness. We will then

focus on its applications in imaging and structuring two-dimensional (2D) materials. We will show

the quantitative extraction of graphene work function by using secondary electron imaging. We

will also demonstrate that structural defects and stoichiometry modification can be controllably

introduced in a few-layer molybdenum disulphide (MoS2) sample at a few-nanometre scale.

Consequently, localised tuning of MoS2 electrical properties can be realized. Fabrication of MoS2

nanostructures with 7 nm dimensions and pristine crystal structure has been also achieved. This

nanoscale modification technique is a generalised approach which can be applied to various two-

dimensional (2D) materials to produce a new range of 2D metamaterials.


22

Recent advances in STEM spectroscopies: a focus on Electron Energy-Loss Spectroscopy and

cathodoluminescence (keynote)

O. Stéphan, J.D. Blazit, L. Bocher, R. Bourrelier, A. Gloter, M. Kociak, A. Losquin, K. March, M.

Marinova‡, S. Meuret, A. Tararan, M. Tencé, L. Tizei, M. Walls, A. Zobelli

Laboratoire de Physique des Solides, bâtiment 510, Université Paris-Sud, 91400 Orsay, France ‡Now at Unité Matériaux et Transformations, Université Lille, 59655 Villeneuve d'Ascq, France

The field of electron energy-loss spectroscopy (EELS) in the scanning transmission electron

microscope (STEM) has recently achieved a succession of impressive successes linked with the

development of aberration correctors, enabling atomically-resolved spectroscopy, which are now

spreading worldwide. A new generation of monochromators is emerging, providing

improvements in energy resolution of at least one order of magnitude and giving unprecedented

access to low energy-loss ranges. Similarly, recent progress in the collection of visible-range

photons emitted by a sample illuminated by a focused beam has enabled novel cathodo-

luminescence (CL) experiments in STEM. In addition, new ways of exploiting fast electron beams,

including combining them with beams of photons, have opened up the field of nano-optics,

providing a high-spatial resolution alternative to more conventional optical techniques.

Some of these new possibilities will be illustrated. Various strategies will be described for the

acquisition of spatially-resolved core-level excitations signals in relation with the quantitative

measurement of electron densities (charge accumulation) or 2D electron gases at interfaces in

oxide-based nanodevices or of functional molecular groups in graphene oxide (GO) and reduced

GO [3]. Recent developments in EELS and CL for reaching plasmon signatures in the visible and

down to the IR spectral range will be described, allowing the mapping of eigen modes in

plasmonic nanostructures and a deep understanding of the physics of these excitation. In

particular, recent EELS experiments at 20 meV resolution as well as experiments combining EELS

and CL will be presented, demonstrating how the usual macroscopic concepts such as extinction,

absorption, and scattering cross-sections have to be adapted to describe optical phenomena at

the nanoscale [4].

Finally, new possibilities for exploring the intimate link between a crystal structure (h-BN), its

defects and its optical properties as revealed by nano-CL [5] will be discussed, together with

some perspectives for entering the field of quantum nano-optics [6].

Keywords: atomically-resolved electron energy-loss spectroscopy, nanocathodoluminescence,

electronic structure at oxyde interfaces, localized plasmons, excitons, quantum nanoemitters, Hanbury

Brown-Twiss experiments

References: [1] M. Marinova et al., Nano Lett. 2533 (2015) 15 [2] M. Guibert et al., submitted [3] A. Tararan et al., submitted [4] A. Losquin et al., Nano Lett., 1229 (2015) 15 [5] R. Bourrelier et al., ACS Photonics 1 (2014) 857 [6] R. Bourrelier et al, unpublished


23

CONTRIBUTED TALKS

Advances in Optical Coherence Tomography

M.J. Leahy1,2, C. Wilson3, J. Hogan3, R. Dsouza1, K. Neuhaus1, D. Bogue3, H. Subhash1,2, Paul M. McNamara1,3and Sergey Alexndrov1

1. Tissue Optics and Microcirculation Imaging Group, School of Physics, National University of Ireland

Galway, Galway, Ireland 2. National Biophotonics and Imaging Platform, Ireland

3. Compact Imaging, Inc., 897 Independence Ave., Suite 5B, Mountain View, CA 94043 USA

Optical Coherence Tomography (OCT) is the fastest growing medical imaging modality, with

more than $400M equipment sales and $1Bln worth of scans in 2010 alone. OCT has the ability

to see 3D sub-surface detail in highly scattering materials such as human tissues including brain,

skin, tooth and bone. Although micron resolution can be achieved, the voxels are typically larger

than other microscopies, whereas the target applications require greater structural sensitivity.

This paper will address key challenges including the ability to separate structure and function[1],

to sense changes on the nanoscale[2] and to improve the resolution[3]. Furthermore, we will

illustrate a solution to provide an OCT system with two orders of magnitude reduction in size and

cost[4], using parts and a configuration similar to a CD-ROM or DVD pickup unit (see figure 1).

Essentially, this is based on the use of a partial mirror in the reference arm of a time domain OCT

system to provide multiple references and hence A-scans at several depths simultaneously (see

figure 2). We have already shown that a system based on this configuration has achieved an SNR

of greater than 90 dB which is sufficient for many applications.

Figure 1. A typical CD-ROM pickup unit. Figure 2. Multiple reference time domain OCT

(MR-OCT) system using a partial mirror.

Keywords: Optical coherence tomography, biophotonics, 3D, nanoscopy, superresolution


24

References: 1, Enfield, J., Jonathan, E. and Leahy, M.J., 2011. In vivo imaging of the microcirculation of the volar

forearm using correlation mapping optical coherence tomography (OCT). Biomedical Optics Express 2 (5) 1184-1193.

2, Alexandrov, S., Subhash, H.M., Zam, A. and Leahy M.J. 2014, Nano-sensitive optical coherence tomography, Nanoscale, 6, 3545-3549.

3, Sergey A. Alexandrov, James McGrath, Hrebesh Subhash, Francesca Boccafoschi, Cinzia Giannini and Martin Leahy. Novel approach for label free super-resolution imaging in far field. Nature Scientific Reports (accepted).

4, Dsouza, R., Subhash, H.M., Neuhaus, K., Hogan, J., Wilson, C., and Leahy, M.J. 2014, Dermascope

guided multiple reference optical coherence tomography, Biomedical Optics Express, 5(9) 2870-2882.


25

Phase retrieval, deconvolution, and resolution in coherent optical microscopy

Mahendar Kumbham, Rabah Mouras, Susan Daly, Kevin O’Dwyer, Syed A.M.Tofail , Christophe

Silien

Department of Physics and Energy, and Materials and Surface Science Institute, University of Limerick, Ireland

In coherent microscopy, the resolution is determined by the coherent optical transfer function

and the images do not systematically afford intuitive representations of the object especially if

the latter affects the phase and is heterogeneous at or below the recording wavelength[1].

Structuring the illumination and patterning the phase are widely exploited and highly successful

strategies for enhancing the resolution in fluorescence microscopy but less so when the imaging

is coherent[2]. In this paper, we discuss a concept of differential imaging in scanning microscopy

where phase patterning is exploited to recover object at resolution higher than afforded by

unstructured Gaussian or plane wave illumination. An iterative phase retrieval has been designed

so that the object amplitude and phase can be effectively deconvolved. Further strategies to

enhance the spatial resolution beyond the microscope coherent optical transfer function are

discussed.

Keywords: Phase retrieval, Optical microscopy, Vortex beam and Gaussian beam

References: 1. Szameit, A., et al., Sparsity-based single-shot subwavelength coherent diffractive imaging. Nature

materials, 2012. 11(5): p. 455-459. 2. Rodrigo, J.A., et al., Wavefield imaging via iterative retrieval based on phase modulation diversity.

Optics express, 2011. 19(19): p. 18621-18635.


26

2.362 ±0.10

* **

A B C

The Development of Plasma Modified Electrospun Poly(L-Lactide-Co D, L-Lactide) Matrices for

the Treatment of Corneal Scarring

Katie-Jo Harwood1, Fabricio M.O. Costa1, Brian J. Meenan1 and George A. Burke1

1, Nanotechnology and Integrated Bioengineering Centre (NIBEC), School of Engineering, Ulster University, N. Ireland

BACKGROUND: Corneal scarring is a serious clinical problem affecting more than 10 million people worldwide. Corneal transplantation (keratoplasty) is the main treatment for repairing visual loss as a result of corneal scarring, but is limited by the lack of available donor corneas; this creates a clinical need for alternative effective treatment protocols. Electrospun (ES) matrices functionalised with dielectric barrier discharge plasma (DBD) polymer fibres have been shown to positively influence cell morphology, proliferation and differentiation. Therefore, they represent an ideal cell delivery vehicle for ophthalmic tissue engineering. The aim of this study was to produce a tissue-engineered construct suitable as a cell delivery vehicle of corneal epithelium.

METHODS: Poly(l-lactide-co-d,l-lactide) (PLDLLA) ES matrices were manufactured and subsequently treated with DBD plasma (250W x 10 cycles & 350W x 10 cycles respectively) to enhance their surface properties. ES matrices were characterised physically (contact angle and SEM), chemically (XPS and FTIR) and biologically (in vitro assays over a 28 day time period using human epithelial cell line HCE-T).

RESULTS: PLDLLA ES matrices displayed a randomly aligned fibre arrangement with an average fibre diameter of 2.36 ±0.10µM (Figure A). DBD treatments chemically altered the surface of the fibres, resulting in a significantly lower contact angle compared to non-plasma treated ES PLDLLA matrices (improved wettability) (Figure B). XPS analysis showed significantly higher surface oxygen content on DBD treated surfaces compared to that of non-plasma treated surfaces. DBD plasma treatment of PLDLLA electrospun membranes significantly enhanced the cellular attachment and proliferation of HCE-T cells (Figure C).

CONCLUSION: This study has concluded that ES PLDLLA matrices support the attachment and proliferation of the HCE-T cell line, thus suggesting that ES PLDLLA matrices have substantial potential as an ophthalmic cell delivery vehicle. Comparison of the different treatment variables suggests that HCE-T cellular response is optimal at the 350W x 10 cycle treatment.


27

SXES: A new detector for Li to U and chemical state analysis in SEM

C. Dickinson1, H. Takahashi2, M. Takakura2, T. Murano2, M.Terauchi3

1, JEOL (UK), JEOL House, Silver Court, Watchmead, Welwyn Garden City, Herts, UK. 2, SM business unit JEOL Ltd., 1-2 Musashino, 3-chome, Akishima, Tokyo 196-8558, Japan.

3, Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan.

There are many types of microanalysis techniques for studying the properties of material.

Commonly on the SEM, they come in the form of EDS, WDS and EBSD. In general, EDS has the

benefit of parallel detection but lacks in energy resolution. WDS has a higher resolution, but it

can only collect one element at a time. For chemical state analysis, the sample has to either use

XPS/Auger or EELS on a TEM. Whilst SEM requires simple preparation techniques, the others

need more advanced preparation due to only collecting surface information (XPS) or making the

sample electron transparent (TEM).

A new technique has been developed for SEM called Soft X-ray emission Spectroscopy (SXES).1,2

With the use of a CCD, an aberration corrected grating and a high energy resolution (0.3 eV for

Al-L), SXES has the benefit of parallel collection and detection of low concentrations of light

elements (20 ppm for B). In addition to this, due to the high energy resolution, bonding state

information can be obtained (π and σ bonding of C). With the high sensitivity, Lithium can also be

detected in both the metallic and the ionic state making it ideal for battery applications (Figure 1).

In this presentation, we will cover the basic principles of the SXES, the differences with other

microanalytical techniques and various application examples.

Figure 1: Location (left) of SXES detector and (right) SXES spectra of Li of batteries in various charged

states.

Keywords: Microanalysis, Spectroscopy, Li Battery, Metals, Chemical State, SEM

References: 1, T. Imazono, et al., Appl. Opt. 51, 2351 (2012). 2, H. Takahashi, et al., Microscopy and Microanalysis, 19 (supple. 2), 1258 (2013).


28

Diffraction tomography and its applications

Andrew Stewart1, Ursel Bangert1,

1, Department of Physics and Energy, University of Limerick, Limerick, V94 T9PX, Ireland.

Microscopy and in particular electron microscopy is normally used to obtain information about

atypical structural information, such as dislocations, interstitial atoms or vacancies, often

assuming the average structure to be known. What happens when faced with crystalline

materials where the average structure is unknown, and the crystals are too small or too few for

X-ray methods to be applied? The recently developed diffraction tomography technique1 can be

applied to determine the average structure of a nanocrystal, extending the applications of ab

initio structure solution by crystallography to the nano domain.

We will present an overview of the diffraction tomography technique with a series of examples

demonstrating the range of potential applications, from geological and biomineralization,

through to pharmaceutical2, and protein crystals.

Keywords: Electron Diffraction Tomography, Nanocrystals, Structure determination.

References: 1, Mugnaioli et al., Ulltramicroscopy, 109 (2009) 758-763. 2, Kolb et al., Polymer Reviews 50 (2010) 385-409.


29

Advances in High Resolution Microanalysis

Chris Stephens

Thermo Fisher Scientific, Birches Industrial Estate,East Grinstead, UK, RH19 1UB

With the advent of silicon drift detector technology, EDS has undergone a revolution in

performance in recent years. Modern Energy dispersive spectroscopy (EDS) detectors boast

increased productivity (larger active areas and higher throughput) with vastly improved spectral

performance (superior light element sensitivity and sharper energy resolution). These advances

in EDS have been so rapid, that many believe the complementary Wavelength dispersive

spectroscopy (WDS) is now obsolete. This conclusion overlooks the existing gaps in EDS

technology and the concurrent revolution in WDS technology. The advent of the hybrid optic and

parallel-beam (PB) WDS technique, coupled with a complete automation of the instrument has

resulted in a modern WD spectrometer that effectively fills the existing, critical gaps in EDS

technology.

This presentation reviews the advances in WDS technology and the analytical space where WDS

effectively complements EDS analysis. Specific WDS application spaces reviewed include: (1)

more accurate quantitative analysis; (2) reduced minimum detection limits; (3) trace element

mapping, in particular for low energy x-rays; (4) analysis and mapping on the nano-scale; (5)

parsing convoluted peak overlaps; particularly below 1 keV; and (6) WDS and EDS phase mapping.

Figure 1: PB WDS (Red, blue) and EDS (Grey) Energy scans of trace (100 PPM) Boron in diamond

Keywords: SEM, WDS, EDS


30

Precipitates in 9-12%Cr ferritic/martensitic heat-resistant steels

Fengshi Yin1, 2, Noel O’Dowd1, Jeremy Robinson1, Woosang Jung3

1, Department of Mechanical, Aeronautical & Biomedical Engineering, Materials & Surface Science Institute, University of Limerick, Limerick, Ireland

2, School of Mechanical engineering, Shandong University of Technology, Zibo 255049, China

3, Division of Materials Science and Technology, Korea Institute of Science and Technology, P.O.Box 131, Cheongryang, Seoul 130-650, Korea

9-12%Cr ferritic/martensitic steels are widely used in USC (Ultra-super Critical) power plants.

Precipitation hardening is the most effective strengthening mechanism in these steels. The

precipitate (morphology, chemistry, crystallography, location) as well as their evolution

behaviour during long term aging have been studied using SEM and TEM. The main precipitates

are M23C6-type carbides located along the grain and lath boundaries and MX-type carbonitrides

in the matrix within laths in the normalized-and-tempered state. Decreasing the carbon content

in the steels causes an increase in the density of nano-sized MX-type precipitates. The ultralow

carbon steel contains a bimodal distribution of nano-sized MX precipitates with a high density in

the matrix but few of M23C6 carbide particles in the normalized-and-tempered state. The larger

MX precipitates have a size of more than 30 nm. The smaller MX precipitates are about 10 nm in

size and have two morphologies: one is cubic and contains titanium, and another rectangular

without titanium. During long-term aging at 923 K (650 °C) for 10000h, the formation of W and

Mo-containing Laves phase and the conversion of nano-sized MX precipitates into coarse Z phase

particles cause significant strength degradation. Titanium can combine with oxygen to form

oxide inclusions which act as the nucleation sites of large titanium-containing MX particles with a

size greater than 1 µm. The large MX particles in high titanium steel cannot be dissolved even at

austenitizing temperature up to 1300 °C. Creep tests indicate that cracks nucleate at the

interface between the matrix and the large MX particles or titanium-containing oxide inclusions.

Key words: 9-12%Cr ferritic/martensitic steels, precipitate, nano-sized MX phase, creep


31

Identification of monolayers and stacking sequences in 2D nanostructures

Aleksey Shmeliov1, Anuj Pokle1, Quentin Ramasse2, Valeria Nicolosi1

1, Trinity College Dublin, CRANN, Dublin 2, Ireland 2, EPSRC National Facility for Aberration Corrected STEM at SuperSTEM, STFC Daresbury Labratory,

Keckwick Lane, Warrington, WA4 4AD, UK

Over the past two decades the development and advancement of aberration-corrected electron

microscopy provided researchers with a powerful characterisation technique capable of sub-

angstrom resolution. This has made it possible to distinguish structural features with atomic

scale resolution and correlate them with the physical properties of the material. Nonetheless,

difficulty and ambiguity in interpretation of certain microscopy techniques reduces reliability of

the results.

In this work reliable identification of monolayers and stacking sequences in 2D nanostructures,

based on annular dark field scanning transmission electron microscopy, ADF STEM, is discussed.

The approach is demonstrated on 2D nanostructures of MoS2 and WS2 [1]. Then this approach is

applied for the structural characterisation of 2D black phosphorous, also known as phosphorene.

While phosphorene came to prominence as potential p-type semiconductor material (both MoS2

and WS2 are n-type semoiconductors), it suffers from environmental damage, limiting its

potential application [2][3]. Our results indicate that monolayers of 2D black phosphorous are

not stable at standard condition for any prolonged periods of time. Such results are somewhat

contrary to the previously reported findings where monolayers were identified via selected area

electron diffraction, SAED [2]. Finally, conditions necessary for reliable identification of the

monolayers with SAED are discussed.


32

Low Frequency Raman Spectroscopy of Two-Dimensional Materials

Maria O’Brien1,2, Niall McEvoy2, Georg S. Duesberg1,2

1 School of Chemistry, Trinity College Dublin 2 CRANN and AMBER, Trinity College Dublin

The growth of the semiconductor industry is anticipated to reach its scaling limit with silicon

CMOS technology in the near future. Many promising candidates have been proposed as

alternative materials, including novel 2D materials, which are attractive candidates due to their

sub-nanometre thickness and direct band gap in their single layer form. Monolayer flakes of

transition metal dichalcogenides (TMDs), such as MoS2 and WS2, have previously been obtained

via a number of techniques including mechanical, chemical, liquid and shear exfoliation, and

chemical vapor deposition (CVD)1. Here, we present a low-frequency Raman analysis of TMDs

such as MoS2, MoSe2, WS2 and WSe2 grown by CVD. Raman spectra are acquired over large areas

allowing changes in the position and intensity of the shear and layer-breathing modes to be

directly visualized in maps2. This allows detailed characterization of mono- and few-layered

TMDs which is complementary to well-established (high-frequency) Raman and

photoluminescence spectroscopy. Thus this study presents a major stepping stone in the

fundamental understanding of layered materials, as mapping low-frequency modes allows the

determination of quality, symmetry, stacking configuration and layer number of 2D materials

over large areas.

Figure 1: Optical image of CVD MoSe2 layers (b) Low frequency Raman spectra of MoSe2 layers (c) Map of

peak maximum position in the low frequency regions for area in (a)

Keywords: Raman spectroscopy, Transition metal dichalcogenides, 2D materials.

References:

1. O'Brien, M. et al. Transition Metal Dichalcogenide Growth via Close Proximity

Precursor Supply. Sci. Rep. 4, 7374 (2014).

2. O'Brien, M. et al. Low wavenumber Raman spectroscopy of highly crystalline MoSe2

grown by chemical vapor deposition. arXiv preprint arXiv:1505.02260 (2015).


33

Failure Identification – Microscopy to the Rescue

Michael Flynn1

1, Analog Devices BV, Raheen Business Park, Raheen, Co. Limerick

At ADI Limerick we research, design, develop, manufacture and test integrated circuits (IC’s).

Microscopy is used across the board from process setup to device characterization. This talk will

focus in on one aspect of how we use microscopy, namely to understand and root cause any

issues that arise during manufacturing.

We use complex manufacturing processes that begin with 8” blank silicon wafers and employ

hundreds of individual steps involving the definition, addition and removal of many different

materials and layers. Once complete the wafer contains either a few hundred to tens of

thousands of IC’s which we call die. The size of these die is dependent on its function and

complexity. Once wafer manufacturing is complete the die are tested for functionality and basic

performance. From this a pass/fail wafer map is generated and only passing die are built into

packages off-shore and tested fully.

Figure 1 - Limerick Manufacturing Flow

Failing die should in most cases be random across the wafer if they are caused by baseline defect

density. We monitor the yield of each wafer and if lower than expected the material is reviewed.

In instances where the failure patterns or types are unusual we analyse and scientifically explain

them to keep the process running issue free. Enter Microscopy.

Trying to find a failure site in a die can be compared to searching for a needle in a hay stack.

Taking you on this journey, this talk will look at one such analysis and describe the techniques

employed to identify and characterize the issue. It will examine fault localization techniques such

as light emission microscopy and analysis techniques such as focused ion beam milling and

scanning electron microscopy.

Keywords: FIB, SEM, Failure Analysis, TEM, FA, LEM, OBIRCH


34

TEM Tomography of Anisotropic Gold Nanoparticles to Develop a Novel Method for Acquiring

Numerical Parameters

J. Cookman1, J. Medieros1,2, Ž. Krpetić1, L. Boselli1, K. A. Dawson1

1. Centre for BioNano Interactions, School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland

2. Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Natal, RN, 59078-900, Brazil

When nanoparticles (NPs) come into contact with biological fluids, proteins can interact with the

surface of the NP forming what is known as a biomolecular corona. In the CBNI extensive studies

have been successful in mapping and characterising the biomolecular corona to better

understand the physiochemical properties required to compose the bio-nano particle1-4. So far

studies have been performed on spherical particles however little is known of the formation of a

protein corona on anisotropic nanoparticles. The knowledge of how nano objects interact with

biological fluid is pertinent for furthering technology in nanomedicine applications, with a prime

focus on the tunable spectroscopic surface properties of anisotropic particles5.

To truly understand how the biomolecular corona might form on the surface of an anisotropic

nanoparticle, more information must be gained of the surface properties. This is complementary

to the surface information that may decide the nanoparticles’ fate in the cell e.g. surface area

and volume.3

The method reported is a fundamental technique in acquiring these surface parameters that play

a major role in determining bionano interactions. By imaging a single nanoparticle via

Transmission Electron Microscopy (TEM) a 2D representation is reported of a 3D object. For

directionally dependent anisotropic nanoparticles this does not present a true description of the

object in view. By acquiring a TEM tomography tilt series of the object at high magnification, a

reconstruction of the nanoparticle can be acquired to result in a 3D wireframe model. From this

3D model we succeeded in calculating essential surface parameters such as surface area and

volume.

This fundamental technique provides the information needed to deeply understand the bionano

interactions of these promising anisotropic nanoparticles with better accuracy than conventional

techniques such as Brunauer Emmet Teller (BET) isotherm for surface area determination6.


35

Figure 1: a) TEM micrograph of a representative star shaped nanoparticle (scale bar: 50 nm), b)

screenshot from Imaris software visualizing the nanostar post reconstruction process contained in an

arbitrary volume, c) the wireframe model of the star shaped nanoparticle after segmentation as viewed in

Paraview and d) surface layer of the nanostar in representative colour of the aqueous suspension.

Keywords: TEM, TEM tomography, gold nanoparticles, anisotropic nanoparticles, shape, nano-bio interactions, wireframe, 3D model, geometry.

References

1. Lundqvist, M.; Stigler, J.; Elia, G.; Lynch, I.; Cedervall, T.; Dawson, K. A. Proceedings of the National

Academy of Sciences 2008, 105, (38), 14265-14270.

2. Hellstrand, E.; Lynch, I.; Andersson, A.; Drakenberg, T.; Dahlbäck, B.; Dawson, K. A.; Linse, S.; Cedervall,

T. Febs Journal 2009, 276, (12), 3372-3381.

3. Walczyk, D.; Bombelli, F. B.; Monopoli, M. P.; Lynch, I.; Dawson, K. A. Journal of the American Chemical

Society 2010, 132, (16), 5761-5768.

4. Kelly, P. M.; Åberg, C.; Polo, E.; O'Connell, A.; Cookman, J.; Fallon, J.; Krpetić, Ž.; Dawson, K. A. Nature

nanotechnology 2015 (AOP).

5. Ozin, G. A.; Arsenault, A. C.; Cademartiri, L., Nanochemistry: a chemical approach to nanomaterials.

2009.

6. Walton, K. S.; Snurr, R. Q. Journal of the American Chemical Society 2007, 129, (27), 8552-8556.


36

Colloidal Cu2ZnSn(SSe)4 (CZTSSe) Nanocrystals- Shape and Crystal Phase control to form Dots,

Arrows, Ellipsoids and Rods

Shalini Singh,†‡ Pai Liu,†‡ Claudia Coughlan,†‡ Matteo Lusi, †‡ Kevin M. Ryan†‡*

†Materials and Surface Science Institute, University of Limerick, Limerick, Ireland ‡ Department of Chemical and Environmental Sciences, University of Limerick, Limerick, Ireland

CZTSSe in colloidal nanocrystal form is a very interesting multi-component semiconductor due to

high absorption coefficient, earth abundance of the constituent elements and band-gap

tunability.1 The occurrence of polytypism between the zinc-blende and wurtzite phases in CZTSSe

nanocrystals is a regular feature of their synthesis due to the low energy differential between the

two crystal phases. Polytypism can be advantageous for thermoelectric applications and equally

disadvantageous for photovoltaics. To-date there is no control of polytypism in the CZTSSe

nanocrystals and also it has not been possible to achieve anisotropic shape control in this system.

A systematic understanding of key influential factors to achieve full control over the occurrence

of polytypism or elimination is highly desirable for optimization of CZTSSe nanocrystals for

different applications.

Herein, we show colloidal synthetic approaches to obtain high degree of shape and phase control

in CZTSSe nanocrystals. The pivotal role of ligands and metal precursors along with temperature

in determining the shape and phase during the nanocrystal growth is demonstrated.2 We show

that under the combined influence of alkylamine and alkylphosphonic ligands, polytypic

nanocrystals could be achieved. The shape of these polytypic nanocrystals could be tuned by the

choice of metal precursors from ellipsoids to arrow-shaped and bullet shaped nanorods. We

have also achieved the formation of pure wurtzite phase 1-D nanorods in this complex quinary

system by substituting alkylamine and phosphonic acids with non-coordinating solvent. The

morphology of differently shaped nanocrystals are well studied by transmission electron

microscopy, scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, X-

ray photoelectron spectroscopy and UV-vis-NIR techniques. As CZTSSe is of interest for a range of

diverse applications, the ability to control both shape and polytypism at the nanoscale in a

colloidal process offers a reproducible route to a wide range of geometries and morphologies

that can be optimised as needed.3


37

Keywords: Polytypism, CZTSSe, Nanorods.

References:

1. A. Singh, S. Singh, S. Levcenko, T. Unold, F. Laffir, K. M. Ryan. Angew. Chem. Int. Ed. 2013, 52, 9120.

2. S. Singh, P. Liu, A. Singh, C. Coughlan, J. Wang, M. Lussi, K. M Ryan. Chem Mater. 2015, 27, 4742.

3. S. Singh, K. M. Ryan. J. Phy. Chem. Lett. 2015, DOI: 10.1021/acs.jpclett.5b01311


38

Controllable doping in graphene and erasable electronic devices by electron beam irradiation

Yangbo Zhou, Pierce Maguire, Daniel Fox, Hongzhou Zhang*

School of Physics and CRANN, Trinity College Dublin, Dublin 2, Ireland.

The electrical properties of graphene are strongly influenced by its carrier type and density, i.e.

the doping states. Electron beam irradiation of graphene has been reported to be an effective

way to tune the doping profile in graphene1. However, the large irradiation doses required

usually cause serious damage in graphene, thus reducing the corresponding device performance.

Here, we present the tuning of the doping profile in graphene by low dose electron beam

irradiation, which maintains the high quality of graphene and allows erasable manipulation of

the doping state.

Figure 1a shows the effect of electron beam irradiation on the electrical properties of graphene.

The electrical properties of a graphene field effect transistor (FET) was characterised via in-situ

measurements in the vacuum chamber of a scanning electron microscope (SEM). The transistor

exhibited high mobility (~ cm2/V.s) and low intrinsic doping. It was then irradiated by a

focused electron beam. Stable n-type and p-type doping could be achieved by varying the

energies of the electron beam, while the doping levels could be controlled by the irradiation

doses. It is found that substrate charging and the induced internal electrical field is responsible

for the doping effect. The doping states could be erased and recreated by a low irradiation dose

(< e-/cm2), which caused negligible damage to the graphene. The high spatial resolution of

electron beam also allows local modulation of the doping state. Multi-doped graphene p-n

junctions could be fabricated (Figure 1b).

In conclusion, we demonstrate the doping effect in graphene by electron beam irradiation. The

carrier types and densities in doped graphene are erasable and locally controllable. The methods

enable a highly spatial resolved, non-destructive and tunable manipulation for graphene

electronic device prototyping.


39

Figure 1 (a) The electric characteristics as a function of gate bias of a pristine, n-doping and p-doping

graphene FET. The n-doping and p-doping was created by the irradiation of a 1 keV and 30 keV electron

beam respectively. Inset, a SEM image of the measured graphene FET, the scale bar is 5 μm. (b) The

electric characteristics as a function of gate bias of a locally modulated p-n junction in graphene (red solid

line) in comparison to its pristine p-doping states (blue dashed line).

Keywords: graphene, doping, electron beam irradiation, erasable devices.

References: 1. Childres, I. et al. Effect of electron-beam irradiation on graphene field effect devices. Appl. Phys.

Lett. 97, 173109, (2010).


40

STEM EELS Analysis of 2D Layered Inorganic Materials at Atomic Resolution

Hannah C Nerl1, Fredrik S Hage2, Lothar Houben3, Quentin M Ramasse2 and Valeria Nicolosi1,4

1. CRANN & AMBER, Trinity College Dublin, Dublin 2, Ireland and School of Physics, Ireland 2. SuperSTEM Laboratory, STFC Daresbury Campus, Daresbury WA4 4AD, UK

. rnst Rus a enter for Microscopy and Spectroscopy with lectrons, Research enter lich, ermany 4. School of Chemistry, Trinity College Dublin, Dublin 2, Ireland

In recent years, methods for the dispersion and exfoliation of 2D nanostructures of a range of

nanomaterials have been successfully developed [1-8], opening up numerous possibilities for a

range of innovative technologies [4, 6-10]. As opposed to mechanically cleaving, liquid phase

exfoliation can produce large quantities of the material, but to make real applications of liquid

phase exfoliated materials feasible there is a need to fully characterize and understand the

impact the production route has on the properties of the nanostructures. In addition, very little is

known about the effect of flake edges or the presence of surface contaminants on the properties

of the materials.

Due to the recent improvements in energy resolution of scanning transmission electron

microscopy electron energy-loss spectroscopy (STEM EELS) [11,12] it is now possible to access

new information such as the near-infrared/visible/ultraviolet spectral range using this technique.

When compared with conventional techniques for measuring optical properties, STEM EELS

offers the unique combination of high spatial as well as energy resolution opening up new

possibilities for studying properties in a localized manner at an unprecedented energy resolution.

For this study we used low-loss STEM EELS using the Nion UltraSTEM100 (SuperSTEM, UK) and

the FEI PICO (Jülich, Germany) to compare the optical properties of MoS2 and other 2D materials

produced by mechanical exfoliation and liquid phase exfoliation. Particular attention was being

paid to changes in the very low loss EELS (energy losses <10eV) and to relate these to changes in

the optical properties when going from multi- to single layered material as well as effects of flake

edges [13]. In addition, we studied the effect of surface contamination and orientation

dependence of the low loss EELS.

Keywords: Low loss, STEM EELS, 2D materials, MoS2, liquid exfoliation, optical properties.

References: [1] AK Geim and KS Novoselov Nature Materials 6 (2007) p.183 [2] SD Bergin et al. Advanced Materials 20, 10 (2008) p.1876 [3] Y Hernandez et al. Nat. Nanotechnol. 3, (2008) p.563 [4] JN Coleman et al. Science 331, (2011) p.568 [5] M Chhowalla et al. Nat. Chem. 5, (2013) p.263 [6] V Nicolosi et al. Science 340, (2013) p.1226419 [7] AK Geim Science 324, (2009) p.1530 [8] KS Novoselov et al. Nature 490, (2012) p.192 [9] QH Wang et al. Nat. Nanotechnol. 7, (2012) p.699 [10] M Osada & T Sasaki J. Mater. Chem. 19, (2009) p.2503 [11] OL Krivanek et al. Nature 464, (2010) p.571 [12] OL Krivanek et al. Microscopy (Oxf). 62 (1), (2013) p.3 [13] C Backes et al., Nat. Comm. 5, (2014) p.4576


41

Application of electron back scattered diffraction to validate a crystal plasticity constitutive

model of a structural steel

Brian Golden1,2, Edward Meade1,2, Yina Guo2, Peter Tiernan2,3 and Noel P O’Dowd1,2

1, Mechanical & Aeronautical Engineering, University of Limerick, Ireland 2, Materials & Surface Science Institute, University of Limerick, Ireland 3, Design & Manufacturing Technology, University of Limerick, Ireland

In this paper we discuss the use of electron back scatter diffraction (EBSD) to quantify

deformation in a mechanically loaded specimen of tempered martensite ferritic steel. A

miniature notched specimen was manufactured from P91 steel and tested at room temperature

under three point bending. A compact tension specimen was also tested in a furnace at 500 °C.

In both cases, EBSD scans before and after deformation have been carried out using a Hitachi SU-

70 scanning electron microscope. The EBSD scan can identify blocks, laths and precipitates within

the steel and also quantifies the change in orientation before and after mechanical deformation.

The measured changes in orientation are compared with those predicted from a finite-element

model. The use of the crystal deformation parameter to quantify changes in material orientation

is also discussed.

Keywords: EBSD, P91 steel, finite-element model


42

Applications of Bruker Four Channel Annular SDD

Chuan Wei CHUNG

Bruker UK, Banner Lane, CV4 9GH, Coventry, UK

The basic form of the silicon drift detector (SDD) has been proposed in 1983 by Gatti & Rehak [1].

Since then improvement in electronics and manufacturing technologies meant that modern SDDs’

performance are far superior to Si(Li) detectors. However, typical mounting point of SDDs on the

incline ports of scanning electron microscopes (SEMs) meant beam sensitive samples;

topographical samples and nanomaterials remain a challenge for energy dispersive spectroscopy

(EDS) analysis. We therefore used a novel configuration of SDD with an annular active area which

allows for large solid and high take-off angle X-rays collection with the aim to address these

modern SDD issues. Some application examples will also be discussed.

Keywords: silicon drift detectors, solid angles, nanomaterials.

References: 1, E. Gatti, P. Rehak, Semiconductor Drift Chamber - An Application of a Novel Charge Transport Scheme,

Nucl. Instr. and Meth. A 225, 1984, pp. 608-614.


43

Ne+, He+ and Ga+ Irradiation for Nanometre Tuning of 2D Materials

Pierce Maguire†,1, Daniel Fox1, Qianjin Wang2, Yangbo Zhou1, Hongzhou Zhang*1

1School of Physics and CRANN, Trinity College Dublin, Dublin 2, Rep. of Ireland 2Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing, P.R. China

Precise modification of two dimensional (2D) material properties will be instrumental in future

device applications. Selected regions of 2D materials (few-layer molybdenum disulphide (MoS2)

and graphene) were altered with He+, Ne+ and Ga+ ion beam irradiation and characterised using

Raman spectroscopy and energy dispersive X-ray spectroscopy (EDX).

The focused ion beam microscope (FIB, employing Ga+) and gas ion microscope (GIM, employing

He+ and most recently, Ne+) are capable of irradiating desired regions with extremely low probe

sizes (0.35-1 nm for He+ and 2-5 nm for both Ne+ and Ga+) with precise doses. In this work, 2D

material modification on the scale of nanometres is presented with extensive control of material

properties, making use of a range of ion species.

The preferential sputtering of sulphur atoms over molybdenum atoms was observed in MoS2,

demonstrating the ability to alter the stoichiometry of a material by ion irradiation as in figure 1.

The full width at half maximum of a Gaussian fitted to the characteristic Raman peaks of a

material is a figure of merit for crystal structure. For graphene, the characteristic peaks are

labelled D and G and for MoS2 the peaks are E12g and A1g. Figures 2 and 3 show the evolution of

some of these peaks with dose for different ions. The dose of Ne+ required to see an equivalent

increase is much lower than for He+. This is in keeping with expectations given the increased

mass of Ne+.

Figure 1: Atomic percentages from EDX of MoS2-x as a function of ion dose (He+).


44

This ion-based, controlled and high resolution technique is a general one which can be expanded

to a great many further 2D material systems. It is demonstrated here as an effective crystal

structure and stoichiometry modification tool.

References [1] Fox, D., et al., Nanopatterning and Electrical Tuning of MoS2 with a Helium Ion Beam. Nature

Nanotechnology, 2015. Submitted.

[2] Fox, D., et al., Helium Ion microscopy of Graphene: Beam Damage, Image Quality and Edge Contrast.

Nanotechnology, 2013. 24(33): p. 335702

[3] Timilsina R. et al., A Comparison of Neon Versus Helium Ion Beam Induced Deposition via Monte Carlo

Simulations. Nanotechnology, 2013. 24(11): p115302

Figure 2: FWHM of characteristic G peak in graphene as a function of ion dose (with

three ion species at 30 kV.

Figure 3: Intensity of characteristic Raman peaks in few layer MoS2 as a function of (a)

Ne+ ion dose and (b) He+ ion dose.


45

Understanding structure-property relationships in nanomaterials

by in situ transmission electron microscopy

Jan Ringnalda1, Emrah Yücelen*1, Joerg R. Jinschek1

1. FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands

Development of new functional nanomaterials and nanosystems play an important role on

advancement of society through more efficient energy use, improvement on energy conversion

process, more efficient transportation and sustainable products with less environmental impact.

Properties of modern nanomaterials are controlled on an atomic scale and thus research and

development of nanomaterials requires atomic scale imaging and analysis see for example [1].

The development of materials or devices with optimized functions often require to perform in

situ studies of actual functional state of the materials at conditions other than the room

temperature and standard high vacuum condition of electron microscope columns.

Implementation of differential pumping apertures in an aberration corrected TEM (FEI Titan

ETEM [2]) enables environmental studies, e.g. oxidation, reduction, or corrosion experiments [3].

On the other hand MEMS technology based in situ heating stages with more accurate knowledge

and temperature control together with very fast settling time enables quantitative atomic scale

studies at elevated temperatures [4]. Recent years have seen the rapid technological

development which enables in situ studies of materials while maintaining high-resolution

imaging and analysis at elevated temperatures, under electrical bias and gas environment [5-8].

In this contribution we will describe the path to have an accurate knowledge and control of

experimental conditions in advanced in situ S/TEM experiments. Special attention will be given

to the image resolution and sensitivity in ETEM gas environments and the temperature accuracy

and uniformity provided by NanoEx™ heating stages [9]. Recent application examples will be

presented to highlight these in situ S/TEM capabilities.

Keywords: HRTEM, HRSTEM, EDS, In-Situ, MEMS devices, environmental (S)TEM

References:

[1] K. W. Urban, Science, 2008, 321, 506–510

[2] http://www.FEI.com/ETEM

[3] E. P. Butler and K. F. Hale, in Practical Methods in Electron Microscopy, ed. M.

Glauert, Elsevier Science Ltd,Amsterdam, 1981, pp. 239–308.

[4] Allard, L. F. et al. Microscopy Research and Technique 72, 208-215P.

[5] P. L. Gai, R. Sharma and F. M. Ross, MRS Bull., 2008, 33, 107–114.

[6] H. Yoshida, Y. Kuwauchi, J. R. Jinschek, K. Sun, S. Tanaka, M. Kohyama, S. Shimada,

M. Haruta and S. Takeda, Science, 2012, 335, 317–319.


46

[7] J. F. Creemer, S. Helveg, G. H. Hoveling, S. Ullmann, A. M. Molenbroek, P. M.

Sarro and H. W. Zandbergen, Ultramicroscopy 2008, 108, 993–998

[8] Malladi, S.K.; Xu, X.; van Huis, M.A.; Tichelaar, F.D.; Batenburg, K.J.; Yücelen, E.;

Dubiel, B.; Czyrska-Filemonowicz, A.; Zandbergen, H.W. (2014) Nano letters, volume

14, pp. 384 – 389

[9] http://www.FEI.com/NanoEx


47

Differential staining of ECM produced by the murine stromal cells

Gill, S.K.1, 2, Ribeiro, A.2, Kilcoyne, M.1, 3, Joshi, L.1 and Ceredig, R.2

1. Glycoscience Group, National Centre for Biomedical Engineering Science, National University of Ireland Galway (NUIG), Ireland;

2. Regenerative Medicine Institute, National Centre for Biomedical Engineering Science and School of Medicine, Nursing and Health Sciences, NUIG, Ireland;

3. Microbiology, School of Natural Sciences, NUIG, Galway, Ireland

Extracellular matrices (ECMs) play important roles in biochemical and biomechanical functions

for the formation, regulation and maintenance of tissues. ECMs determine the interaction of the

cells with their microenvironment via cell signalling and shape and stability of tissues. They are

highly dynamic structures remodelled in response to various external stimuli. MS-5 cells

represent a continuously growing clone of mouse mesenchymal stromal cells (MSC) and support

human hematopoietic stem and progenitor cell survival and differentiation. The environmental

conditions are known to alter the differentiation fate of the stem cells grown over the stromal

cells. We have previously shown that the hypoxic environment influences the differentiation

capacities of MS-5 and other continuously growing mouse MSC lines (1)(2). The aim of this work

is to demonstrate how hypoxia affects the glycosylation of the ECM components.

Proteomic analysis was performed on the decellularized MS-5 cell ECM under normoxic and

hypoxic conditions and glycosylation alterations were inferred by differentially regulated

glycosyltransferases. Lectin histochemistry and lectin blotting were carried out to investigate the

differential binding due to the differential production of ECM by the stromal cells. In silico

analysis indicated that one of the most relevant pathways affected by hypoxia was the ECM

receptor interaction pathway. The altered glycomic profiling further focused on modifications of

molecules involved in cellular signalling. This work has implications on maintaining stemness of

the stromal cells and understanding complex network communications in identifying the relevant

ECM molecules.

Keywords: Extracellular matrix, Lectins, Lectin blots.

References:

1. Prado-Lopez, S., et al. The influence of hypoxia on the differentiation capacities and immunosuppressive

properties of clonal mouse mesenchymal stromal cell lines. Immunology and cell biology. Immunology and

Cell Biology, 2014, 92, 612–623.

2. Sugrue, T., et al., Hypoxia enhances the radioresistance of mouse mesenchymal stromal cells. Stem Cells.

2014, 32, 8, 2188-200.


48

Piezoresponse (PFM) and Transmission Electron Microscopy (TEM) study of Boron Nitride

Nanotubes (BNNT)/ Polymer Nanocomposite: Effect of Polydopamine Coated BNNTs on

Human Osteoblats (HOB’s).

Marc A. Fernandez-Yague 1, Aitor Larrañaga 1-2, Olga Gladkovskaya 1, Alanna Stanley 3,Ghazal

Tadayyon 1, Yina Guo 4, Jose-Ramon Sarasua 2, Tofail, Syed 4, Dimitrios Zeugolis 1, Abhay Pandit 1,

Manus J. Biggs 1.

1. Centre For Research in Medical Devices (CURAM), National University of Ireland Galway (NUIG), Galway, Ireland

2. School of Engineering, University of the Basque Country (UPV/EHU), Department of Mining-Metallurgy Engineering and Materials Science & POLYMAT

3. Department of Anatomy, National University of Ireland Galway (NUIG), Galway, Ireland 4. Materials and Surface Science Institute (MSSI), University of Limerick, Limerick, Ireland

Boron nitride nanotubes are currently being proposed for a number of applications ranging from

nanosensors to polymeric nanocomposite1 devices since they possess a very desirable and

unique combination of physical properties,2 of value in biomedical applications. However,

attempts to use boron nitride in composite materials have produced results that are far less than

what is possible because of poor dispersion of nanotubes and agglomeration of the nanotubes in

the host material. In the present study, we report a process for the efficient disentangled BNNT

via non-colavent chemical modification of BNNT due to the large π-electronic surface formed by

wrapped layers of hexagonal BN that is able to interact with organic molecules via π-π stacking

and improve BNNT dispersibility in aqueous solvents. High resolution Transmission electron

Microscopy was used to investigate the effects of the organic coating on the dispersion.

Furthermore, the cytocompatiblity of coated BNNT was assessed in vitro with cultured human

osteoblasts demonstrating that BNNTs become individually localized within the cytoplasm by

endosomal escape. Eventually, BNNTs were incorporated into electropsun PVDF-TrFE fibres and

piezoreponse microscopy was carried out showing no adverse effect on the piezoelectricity level

of the fibres.

Figure 1: Scheme of the functionalization process for the coating of BNNT and the localization of

individualized BNNT escaping from an endosome.

Keywords: piezoresponse , transmission electron miscroscopy, boron nitride nanotube


49

References:

1. Lahiri, D., Rouzaud, F., Richard, T., Keshri, A. K., Bakshi, S. R., Kos, L., and Agarwal, A. (2010) Boron

nitride nanotube reinforced polylactide-polycaprolactone copolymer composite: mechanical

properties and cytocompatibility with osteoblasts and macrophages in vitro. Acta biomaterialia 6,

3524-33.

2. Nigues, A., Siria, A., Vincent, P., Poncharal, P., and Bocquet, L. (2014) Ultrahigh interlayer friction in multiwalled boron nitride nanotubes. Nature materials 13, 688-93.


50

Magnetic Nanoparticle Interactions with Biological Systems

– Non-Invasive Monitoring

D. Soukup1, S. Moise1, E. Céspedes1,2, J. Dobson3 and N. D. Telling1

1. Institute for Science and Technology in Medicine, Keele University, ST4 7QB, UK 2. IMDEA NANOCIENCIA, C/ Faraday, 9 Ciudad Universitaria de Cantoblanco, 28049 Madrid, SPAIN

3. J.Crayton Pruitt Family Department of Biomedical Engineering & Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611, USA

The potential use of nanoparticles in medicine is an example of how research at the interface

between material and biological sciences can bring benefits and more complete understanding

to both fields of endeavour. For successful cell-based applications of magnetic nanoparticles

(MNP), it is important to be aware of any change in MNP properties throughout their whole life

cycle. It may occur at each step due to the development of the protein corona, clustering,

changes in magnetic response or degradation of MNP. We address all of the above using a novel

application of AC-susceptometry to precisely monitor the stability and follow the in situ magnetic

response of magnetic nanoparticles, from water-based suspensions to cell culture media,

following their cellular internalisation and subsequent release by freeze-thaw lysis [1]. The

results demonstrate that cellular internalisation can alter magnetisation relaxation, which has

significant implications for designing suitable nanoparticles for intracellular hyperthermia

applications. Further, our results indicate that clustering occurs due to the ionic strength while

the serum proteins (FBS) help to stabilise the MNP due to the development of protein corona

which also increases the bioavailability. The FBS functionalized MNP (FBS-MNP) showed a

significantly enhanced stability in media. In addition, we used the AC-susceptometry to non-

invasively monitor and quantify the uptake of MNP in vitro in live cells which has huge potential

for monitoring the uptake of MNP in vivo. Two cell culture configurations were tested; inverted

cells at the top of the well and conventionally cultured cells at the bottom of the well. Our results

indicate that stability of MNP can alter the uptake due to sedimentation. Unstable MNP, forming

large clusters in cell culture media, tend to be internalised in much higher amounts in

comparison with FBS-MNP that are stable and well-dispersed for conventionally cultured cells –

implications on in vitro studies.

Keywords: magnetic nanoparticles (MNP), serum proteins (FBS)

References:

[1] In Situ Measurement of Magnetization Relaxation of Internalized Nanoparticles in Live Cells. Dalibor Soukup, Sandhya Moise, Eva Céspedes, Jon Dobson, and Neil D. Telling, ACS Nano 2015 9 (1), 231-240


51


52

Poster list

1. Michele A. Corrigan Quantification of Fluorescent Calcium Biosensor Signals in Real-time within Discrete Subcellular Compartments of Mesenchymal Stem

2. Martin Sheehan Growth of Crystalline Nickel Germanide Nanowires within the vapour

phase of a High Boiling Point Solvent System 3. Daniel Fox Nanopatterning and Electrical Tuning of MoS2 layers with a Helium Ion

Beam 4. Grace Flynn Characterisation of Tin Seeded Multi-Segment Silicon-Germanium Axial

Heterostructure Nanowires 5. Alan J Harvey Thin MAX phases: MXenes – a new type of 2-D material? 6. Cian McKeown Defect formation in multi-layered metal structures after high

temperature annealing 7. Maryam Karimijafari Grain Orientation in Ferroelectric Ceramics with EBSD Technique 8. Fiona Rogan Evaluation of Acute Cardiac Damage in Swine Following Resuscitation – A

Microscopic and Genomic Pilot Study 9. Yina Guo Effect of hot compression and cooling rate on the microstructure and

texture formation in Ti-6Al-4V alloy used for linear friction welding 10. Aimee Stapleton Piezoresponse Force Microscopy: A Tool for Investigating

Electromechanical Properties of Biomaterials at the Nanoscale 11. Rachel Ronan Glycobiology of the spinal cord in tadpole Xenopus laevis 12. Robert O’Connell Optical properties of charged particle induced carbon profiles 13. Ian Woods Application of a rolled-sheet fabrication technique to improve full-

thickness cellularisation of nanofibrous tissue-engineered vascular grafts 14. Cian Nash The structure of the inkjet printed layers and their electrical properties 15. Claudia Coughlan Diffraction Contrast Effects in CuInGa(S1-xSex)2 Semiconductor

Nanocrystals 16. Rajesh K. Sharma Generation and characterisation of novel antibody fragment molecules

for specific detection of Neu5Gc on tissues 17. Gazal Tadayyon Microstructural changes in heat treated Ti-rich NiTi shape memory alloy


53

18. Eoin Hinchy Characterising the Interaction of Diffusion Braze with Welded and Single Crystal Nickel-Based Superalloy Substrates Using SEM and EBSD

19. Ursel Bangert Seeing the whole picture- advantages and shortcomings of EFTEM

20. Catherine Adley Bacteria that travel: biofilm in aircraft water systems 21. Tadhg Kennedy Lithium Alloying Nanostructured Anodes with High Capacity and Power

Performance 22. Evie Doherty In Situ TEM Characterisation of 2-Dimensional Materials in Liquids for

Energy Storage and Optoelectronics Applications 23. Kerry Thompson ‘Under the Microscope’ - A Microscopy Outreach Pilot Programme 24. Wynette Redington Bright stars in Science


54

POSTERS

1. Quantification of Fluorescent Calcium Biosensor Signals in Real-time within Discrete

Subcellular Compartments of Mesenchymal Stem Cells under physiological loading.

Michele A. Corrigan1,2,3, Kristen L. Lee4, Marie-Noëlle Labour1,2,3, Christopher R. Jacobs4, David A.

Hoey1,2,3,5

1, Department Mechanical, Aeronautical and Biomedical Engineering, University of Limerick, Limerick, Ireland.

2, Centre for Applied Biomedical Engineering Research, University of Limerick, Limerick, Ireland. 3, Materials and Surface Science Institute, University of Limerick, Limerick, Ireland.

4, Department of Biomedical Engineering, Columbia University, New York, New York, 10027, USA. 5, Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Ireland.

Calcium ions undergo rapid transport throughout the cell and across membranes, thus acting as

an essential second messenger in most cellular pathways1. Primary cilia are antenna like cellular

compartments that protrude from the cell surface and are distinct from the cytoplasm. Cilia

have been hypothesised to act as cellular mechanosensors whereby bending of the cilium under

fluid flow triggers a flux in intracellular calcium2. Furthermore cilia are required for mesenchymal

stem cells (MSCs) mechanotransduction3, however the molecular mechanisms of cilia-mediated

mechanotransduction in MSCs are unknown. This study aimed to determine whether this

mechanism may be mediated by calcium signaling. To achieve this we developed a system

consisting of two genetically encoded calcium indicators to capture activity in multiple cellular

subcompartments such as the cilium. Firstly, a FRET (Fluorescence Resonance Energy Transfer)

based calcium biosensor was linked to the cilium specific GTPase Arl13b and secondly, a single

fluorescence sensor was expressed in the cytoplasm (Figure 1). A filter wheel (0.65Hz) allows the

two biosensors to be excited in quick succession, the emitted light is directed to a beam splitter

and highly sensitive camera so that the activity at both sensors can be analysed individually.

Upon application of fluid flow a peak in calcium signal was detected within the cilium (Fold

increase = 1.5) and also detected within the cytosol (Fold increase = 2.5). Immunocytochemical

analysis identified potential mediating calcium permeable channels TRPV4 and PC2 localized to

the primary cilium. Inhibition of either eliminates the calcium response to flow. Our data

indicates that under fluid flow, there is a discrete calcium response within the cilium which is

believed to trigger a cascade of downstream events. The biosensors developed in this study

allow real time quantification of second messenger molecules in specific subcellular locations,

aiding our understanding of molecular mechanisms mediating cellular responses.


55

Figure 1: Calmodulin based calcium biosensors (a) localized to the primary cilium via the cilium specific

GTPase Arl13b (Emission 530nm) and (b) expressed in the cytosol (Emission 592nm).

Keywords: Fluorescence Resonance Energy Transfer, Biosensor, Calcium, MSC

References: 1, Clapham, 2007. Cell 131(6)1047-1058. 2, Nauli et al., 2003. Nature genetics 33(2)129-137. 3, Hoey et al., 2012. Stem cells 30(11) 2561–70.


56

2. Growth of Crystalline Nickel Germanide Nanowires within the vapour phase of a High Boiling

Point Solvent System

Martin Sheehan, Grace Flynn, Yina Guo, Kevin M. Ryan*,

Materials and Surface Science Institute, University of Limerick

Transition metal germanides and silicides are a broad set of materials which are finding a number

of potential applications in a variety of areas. In particular in microelectronics, where the

inherent compatibility with group IV materials makes transition metal germanides particularly

exciting for applications such as local interconnects, where low resistivities combined with stable

crystal structures are desirable.

This increasing interest in transition metal germanide NWs, as well as transition metal silicide

NWs, has led to the development of a number of different synthetic protocols. Recently, our

group advanced the established solvent vapour growth (SVG) system [1] to grow copper silicide

(Cu15Si4) NWs from bulk Cu foil [2].

Here, we report the synthesis of nickel germanide NWs from a Ni substrate using the SVG system.

The SVG system uses the vapour portion of a high boiling point solvent as a reaction medium to

reach the temperatures required for Ge precursor decomposition and NW growth. NW growth is

initiated through the thermal decomposition of a suitable organometallic germanium precursor.

Initially, as Ge is provided to the Ni substrate and a rough nickel germanide layer is formed. As

the reaction proceeds, NWs begin to grow from this rough germanide layer.

SEM Analysis of the Ni substrates post-reaction shows that the nickel germanide NWs grown can

be grown up to 5 µm in length and display tapered morphologies (Fig. 1). Through XRD, HRTEM

and electron diffraction analysis the phase of the NWs was determined to be orthorhombic NiGe.

Figure 1: SEM image of NiGe NWs from Ni substrate

Keywords: Nickel Germanide, Nanowire, Solvent Vapour Growth, Synthesis. References: 1, C. A. Barrett, H. Geaney, R. D. Gunning, R. D, F. R. Laffir, K. M. Ryan, (2011) Chem. Commun. 47,

84 − 845. 2, H. eaney, . Dic inson, . O’ Dwyer, . Mullane, A. Singh and K. M. Ryan. (2012), Chem Mater., 24 (22),

4319–4325.


57

3. Nanopatterning and Electrical Tuning of MoS2 layers with a Helium Ion Beam

Daniel Fox, Yangbo Zhou, Pierce Maguire, Hongzhou Zhang


Control of material properties is a key research goal, especially at the atomic scale. Two-

dimensional (2D) materials provide an ideal platform to realise atomic scale modification. A

prime example of such a material is molybdenum disulphide (MoS2). Bulk MoS2 is a

semiconductor with an indirect band gap of 1.2 eV. However, when isolated as a monolayer it

has a 1.8 eV direct gap. Monolayer MoS2 has many applications such as optoelectronic devices,

gas sensing and energy storage. A greater range of applications, such as photovoltaic cells and

spintronics, can be realised by control of the electrical and magnetic properties. This can be

achieved by tailoring the crystal structure, chemical composition and geometry of MoS2.

A sub-nanometre, highly focused, helium-ion beam was used to controllably introduce defects

and fabricate sub 10 nm nanostructures in 2D materials such as MoS2. The change in crystal

structure was analysed by Raman spectroscopy and transmission electron microscopy (TEM). The

stoichiometry of MoS2 was modified by preferential sputtering of sulphur at a few nm scale, as

shown by energy dispersive X-ray spectroscopy (EDX). Electrical characterisation demonstrated

localised tuning of the material’s resistivity. Semiconducting, metallic or insulating MoS2 was

obtained by irradiation with different doses of He+ (Fig. 1a). Fabrication of MoS2 nanostructures

with sub 10 nm dimensions and pristine crystal structure was also achieved (Fig. 1b). The edges

of these nanostructures showed minimal damage extension, typically confined to within 1 nm.

Nanoribbons with widths as small as 1 nm were reproducibly fabricated. This nanoscale

modification technique is a generalised approach which can be applied to various two-

dimensional materials to produce a new range of 2D metamaterials.

Figure 1: (a) Electrical resistivity and behaviour of MoS2 as a function of He+ dose. (b) TEM image of a 9nm

MoS2 nanoribbon with pristine crystal structure, as confirmed by inset FFT, fabricated in the HIM1.

References: [1] Fox, D., et al., Nanopatterning and Electrical Tuning of MoS2 with a Helium Ion Beam. Nano Letters,

2015. DOI: 10.1021/acs.nanolett.5b01673.


58

[2] Fox, D., et al., Helium ion microscopy of graphene: beam damage, image quality and edge contrast. Nanotechnology, 2013. 24(33): p. 335702

[3] Fox, D., Zhou, Y. B., and Zhang, H. Z., Helium Ion Microscopy for Graphene Characterization and Modification, in Nanotubes and Nanosheets: Functionalization and Applications of Boron Nitride and Other Nanomaterials, Y. Chen, Editor. 2015, CRC Press.


59

4. Characterisation of Tin Seeded Multi-Segment Silicon-Germanium Axial Heterostructure

Nanowires

Flynn, G. 1 Ramasse, Q.M. 2 and Ryan, K.M. 1

1 Materials and Surface Science Institute and Department of Chemical and Environmental Sciences, University of Limerick, Limerick, Ireland

2 SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury WA4 4AD, UK

Silicon (Si) and germanium (Ge) nanowires (NWs) are very promising materials for their use in

applications such as energy storage, transistors and photovoltaics. Compound semiconductor

NWs are of particular interest for their potential use in high performance devices. Herein, we

present the high density growth of multi-segment axial Si-Ge heterostructure NWs (hNWs) in a

versatile, low cost glassware system, where the vapour phase of a high boiling point solvent acts

as the growth medium. A variety of hNW combinations can be grown in this solvent vapour

growth (SVG) system, including Si-Ge, Ge-Si, Si-Ge-Si, Ge-Si-Ge, Si-Ge-Si-Ge and Si-Ge-Si-Ge-Si-Ge,

with minimal alloying observed at the Si to Ge and Ge to Si interfaces. An evaporated layer of tin

(Sn), on stainless steel was chosen as the growth substrate. Sn was chosen as it is a low solubility

type B catalyst which allows for the production of highly abrupt interfaces between the Si and Ge

segments. The length of each Si and Ge segment can also be controlled in this system by carefully

controlling the reaction time. These hNWs are characterised using transmission electron

microscopy (TEM), aberration corrected scanning transmission electron microscopy (STEM) and

electron energy loss spectroscopy (EELS), which allows for the determination of the interfacial

abruptness between the Ge and Si segments.

Figure 1: Schematic of the SVG system and the multi-segment hNW types achievable

Keywords: silicon, germanium, heterostructure nanowires, aberration corrected STEM, EELS


60

5. Thin MAX phases: MXenes – a new type of 2-D material?

Niall Hore 1, Alan J. Harvey1, Vladimir Vishnyakov2, Andrew Stewart 1, Recep Zan3, Ursel Bangert1

1, Department of Physics and Energy, Limerick, University of Limerick 2, School of Computing and Engineering, University of Huddersfield, HD1 3DH, UK

3, School of Materials,The University of Manchester, Manchester M13 9PL, UK

MAX phases are a class of natural nanolaminates which have been intensively researched all over

the world since the early 1990’s due to their atomically thin structure and chemical, physical,

electrical and mechanical properties which combine many characteristics of ceramics and metals

[1]. Since 2011 it has been found that these MAX phases can be extracted/formed into 2-

Dimensional materials of early transition metal carbides and carbo-nitrides referred to as

MXenes. Recently different samples of the MAX phase Cr2AlC have been successfully deposited

on suspended graphene at 5000C and 600⁰C utilising a unique layer-by-layer magnetron physical

vapour deposition technique. These samples have been analysed using TEM and EDX. From

viewing the samples using TEM it appears that the graphene membranes are still present in

sections of the samples and the deposited phase formed a nano-crystalline thin layer with island

like morphology. There also is evidence that the epitaxial relationship varies with the

morphology of the substrate e.g., thinnest crystals are in uniform dispersion on the suspended

graphene monolayer [2]. EDX is used to investigate the composition, with indication of varying

ratios of Aluminium and Chromium; this poses the question of the formation of different MAX-

or MXene-phases. Atomic resolution high angle annular dark field images, however, reveal the

same structural appearance throughout. Further investigations in order to help resolve this issue

will include structure modelling and image simulations.

Keywords: MAX Phase, MXene.

References: [1] M. R. M.W. Barsoum, “ lastic and Mechanical Properties of the MAX Phases,” Annu. Rev. Mater.

Res, 2011. [Online]. Available: http://www.annualreviews.org/doi/pdf/10.1146/annurev-matsci-062910-100448. [Accessed: 29-Oct-2014].

[2] R Zan; V Vishnyakov; U Bangert; Y Guo; M Halsall; J Proctor; J Colligon " Growth and Structure of Physical Vapour Deposition grown MAX phase on Graphene", IMC2014 Prague


61

6. Defect formation in multi-layered metal structures after high temperature annealing

Cian McKeown and Fernando M. F. Rhen

Department of Physics and Energy, Materials and Surface Science Institute, University of Limerick, Ireland

Pit formation is known to be a mechanism for releasing strain energy in thin films [1]. The

formation of deep substrate pits can greatly affect the surface of a material and can have

detrimental effects on the electrical performance of these devices by decreasing carrier mobility

[2]. Here, we investigate the formation of defects caused by high temperature annealing of Si

substrates coated with a variety of transition metal layers prepared by sputtering. We used

scanning electron microscopy (SEM) to examine the nature of the pits, from pit growth and

surface coverage to size, shape and surface morphology measurements. Figure 1 illustrates the

formation of pits in micron scale. We observed the formation of pits with sizes ranging from

hundreds of nanometres to tens of microns. The pits grow parallel and perpendicular to each

other, indicating growth along the crystallographic plane.

Strain is caused during high temperature annealing of sputtered metallic trilayers. Pit formation,

and therefore surface strain is only observed in trilayers where the surface metal has a

coefficient of thermal expansion lower than the layers below it. By comparing two systems of

metallic trilayers; one with increased surface strain energy and one without, we show that deep

penetrating substrate pits only form on the former. Raman spectroscopy can be used to observe

the changes in surface strain energy [3]. Raman spectroscopy was used to observe the strain

change due to each metal layer and the effect of high temperature annealing on the strain in the

films.

Figure 1. Scanning electron micrograph of metallic trilayer on silicon substrates showing large pits penetrating into the substrate. On the left, a) shows a high magnification SEM image of a large pit defect while b) shows the defect formation across the surface of the film in micron scale.

References: [1] D.E. Jesson, K.M. Chen, et al., Phys. Rev. Lett. 77, 1330 (1996) [2] E. Escobedo-Cousin, S.H. Olsen, et al., J.Phys. D: Appl. Phys. 42 175306 (2009) [3] C.H. Jang, S.I. Paik, Y.W. Kim, N.E. Lee, App. Phys. Lett. 90, 091915 (2007) Acknowledgement:

This research is supported by Science Foundation Ireland grant number 12/IP/1692.


62

7. Grain Orientation in Ferroelectric Ceramics with EBSD Technique

Maryam Karimijafari1,2, Yina Guo2, Katarzyna Kowal1,2, Katherine O’Sullivan3, Anthony Maher3,

Abbasi Gandhi1,2 and Syed A.M.Tofail1,2

1 Department of Physics and Energy, University of Limerick, Ireland 2 Materials and Surface Science Institute, University of Limerick, Ireland 3 BorgWarner Tralee Ltd, Monavalley Industrial Estate Tralee, Ireland

Ferroelectrics are a subgroup of pyroelectrics showing spontaneous polarization when they are

getting cool below the Curie point[1]. Both piezoelectricity and pyroelectricity are anisotropic

properties and averaged in polycrystalline ceramics. As a result of sintering polycrystalline

ceramics such as pyro and piezoelectrics, small anisotropy may occur (5-10%)[2, 3]. Local

anisotropy in individual grains may not be all cancelled if an overall net anisotropy prevails.

Differences between grains size and shape in sintered materials can be observed in Scanning

Electron Microscopy (SEM) (see Figure 1a), however Electron back scattered diffraction (EBSD) is

a useful method to determine crystal orientation and anisotropy at the level of individual grains.

EBSD microscopy involves understanding the structure, crystal orientation and phase of materials

in the Scanning Electron Microscope (SEM). In the EBSD technique diffracted backscattered

electrons are collected forming a pattern on a phosphor screen in the SEM chamber. This

diffraction pattern gives valuable information, such as grain size, pole figure and orientation

mapping. In this study individual orientations of grains in ferroelectric BaTiO3 ceramics were

studied by the EBSD technique. An example of an EBSD map is presented in Figure 1b. No

preferential orientation was observed in the sample, but local preferred orientation and

anisotropy have been noted in the studied sample (BaTiO3). Sample surface smoothness is really

important to get good results. Moreover, the sample should be highly tilted between 60° to 80°

towards the detector in order to enhance the quality of pattern which will be achieved.

Figure 1a: SEM image of BaTiO3 Figure1b: EBSD pattern of BaTiO3

Keywords: Electron back scattered diffraction, ferroelectrics, grain orientation.

References:

1. Richerson, D.W., Modern ceramic engineering: Properties, processing, and use in design. second ed. 1992.

2. Tofail, S.A.M., et al., Pyroelectric surface charge in hydroxyapatite ceramics. Journal of Applied Physics, 2009. 106(10): p. 106104.

3. Tofail, S.A.M., et al., Direct and ultrasonic measurements of macroscopic piezoelectricity in sintered hydroxyapatite. Journal of Applied Physics, 2009. 105(6): p. 064103.


63

8. Evaluation of Acute Cardiac Damage in Swine Following Resuscitation – A Microscopic and Genomic Pilot Study

Fiona Rogan1, Gerry Mahon2, Laura Davis3, Rebecca Di Maio3, Brian J Meenan1 and George A.

Burke1

1, Nanotechnology and Integrated Bioengineering Centre (NIBEC), School of Engineering, University of Ulster, N. Ireland.

2, Centre for xperimental Medicine, Queen’s University Belfast, N. Ireland. 3, HeartSine Technologies Ltd., Belfast, N. Ireland.

Introduction: Transthoracic defibrillation is performed to correct life threatening cardiac

arrhythmias of the heart, such as ventricular fibrillation (VF) and ventricular tachycardia (VT),

which could result in cardiac arrest. These arrhythmias are treated by the delivery of an electrical

shock from a defibrillator across the heart, of sufficient magnitude to depolarise a critical mass of

myocardium, helping restore normal electrical activity and a perfusing heart rhythm. In the event

of sudden cardiac arrest, the 2010 American Heart Association (AHA) guidelines recommend

defined cardiopulmonary resuscitation (CPR) conditions and defibrillation energies to assist

patient recovery. While it is accepted that resuscitation is required for life saving events, in

recent years, questions have arisen about the potential of these techniques to cause myocardial

damage. This pilot study aimed to examine changes in cardiac tissue ultrastructure and gene

expression following resuscitation.

Methodology: Following the induction of VF in a porcine model, resuscitation was performed as

per the recommended guidelines. Upon completion of the resuscitation protocol, animals were

euthanised and cardiac tissues collected for histopathological processing and scanning electron

microscopy (SEM) examination with RNA isolated for gene expression analysis.

Results: Histological and SEM analysis suggest that resuscitation causes little discernible

structural changes to the porcine cardiac tissue (Figures A & B). However, qPCR analysis suggests

resuscitation induces changes in the cardiac tissue mRNA expression (Figure C).

Discussion: This small pilot study aimed to assess the extent of acute myocardial damage at a

structural and genomic level associated with implementing current resuscitation guidelines. It is

evident that additional research is required to fully investigate post resuscitation cardiac damage

using a range of conversion energies and CPR technique and duration.


64

9. Effect of hot compression and cooling rate on the microstructure and texture formation in

Ti-6Al-4V alloy used for linear friction welding

Yina Guo1, HangYue Li2, Simon Bray3

1, Materials & Surface Science Institute, University of Limerick, Ireland 2, School of Metallurgy and Materials, University of Birmingham, UK

3, Rolls-Royce Plc, Derby, UK

Gleeble tests were carried out to investigate the effect of pressure on the microstructure and

texture evolution in Ti64 alloy in order to further understand the variant selection effect in linear

friction welding of Ti64. The samples were tested under different pressures in the β phase field

and at different cooling rates. The resulting microstructures were then measured by SEM, EBSD

and XRD to investigate the microstructural features and texture. It has been found that the

cooling rate has significant effect on the size of the microstructural features, but negligible effect

on the texture formation. A pressure of 10 MPa was found to be not enough to generate

significant texture in the microstructure. On the contrary, a pressure of 100 MPa in the β phase

field generated pronounced texture in the sample.

Keywords: LFW, texture, variant selection, Gleeble, EBSD

References: 1, Bhamji, I., et al., Solid state joining of metals by linear friction welding: a literature review. Materials

Science and Technology, 2011. 27: p. 2-13. 2. Jiang, J.Y., et al., Fatigue Threshold of Friction Welded Ti-6Al-4V, in 9th International Conference

on Trends in Welding Research. 2012: Chicago, USA. 3. Karadge, M., et al., Texture development in Ti-6Al-4V linear friction welds. Materials Science and

Engineering A, 2007. 459(2007): p. 182-191.


65

10. Piezoresponse Force Microscopy: A Tool for Investigating Electromechanical Properties of

Biomaterials at the Nanoscale

A. Stapleton1,3, M. R. Noor2,3, C. Silien1,3, T. Soulimane2,3, S.A.M. Tofail1,3

1 Department of Physics and Energy 2 Chemical and Environmental Sciences Department

3 Materials and Surface Science Institute, University of Limerick, Ireland

The functionality of many devices including ferroelectric capacitors, piezoelectric energy-

harvesters and actuators are controlled by the electromechanically coupling of their composite

materials. Similarly, physiological processes such as the amplification of sound for hearing[1], and

the voltage-gating of ion channels as a means of cell-cell communication[2], rely on

electromechanical coupling. The structural and physical properties of materials can be

investigated with an atomic force microscope, using an ultra-sharp cantilever tip to ‘feel’ the

material surface as it scans. In order to investigate electro-mechanical properties, the capabilities

of the standard AFM must be extended. Piezoresponse force microscopy (PFM) is an adaption of

the classical AFM technique which simultaneously uses the cantilever tip to apply a voltage

across the sample during scanning and monitor the sample response. In the case of piezoelectric

materials, the applied voltage induces deformations, which can be sub-picometer in magnitude.

PFM also allows for the investigations of ferroelectric materials; a sufficiently high bias applied by

the tip causes the polarity of ferroelectric domains to switch. PFM studies have contributed to

our knowledge of piezoelectricity and ferroelectricity in many biological specimens including

amino acids[3], collagen[4] and hydroxyapatite[5]. In our work, we utilise PFM alongside other

classical methods of piezoelectric characterisation to investigate the origin and function of

piezoelectricity in proteins.

Keywords: Atomic Force Microscopy, Piezoresponse Force Microscopy, Piezoelectricity, Ferroelectricity,

Biomaterials.

References:

1. Dallos, P. and B. Fakler, Prestin, a new type of motor protein. Nature Reviews Molecular Cell Biology, 2002. 3(2): p. 104-111.

2. Blunck, R. and Z. Batulan, Mechanism of electromechanical coupling in voltage-gated potassium channels. Frontiers in pharmacology, 2012. 3.

3. Heredia, A., et al., Nanoscale Ferroelectricity in rystalline γ‐ lycine. Advanced Functional Materials, 2012. 22(14): p. 2996-3003.

4. Denning, D., et al., Piezoelectric properties of aligned collagen membranes. Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2014. 102(2): p. 284-292.

5. Gandhi, A.A., et al., Piezoelectricity in Poled Hydroxyapatite Ceramics. Journal of the American Ceramic Society, 2014.

Acknowledgement: Funding from the Irish Research Council (IRC) EMBARK Postgraduate Scholarship

(2012-2015) to APS is acknowledged.


66

11. Glycobiology of the spinal cord in tadpole Xenopus laevis

Rachel Ronan1,6, Aniket Kshirsagar1, Kerry Thompson2, Lokesh Joshi1,3,4, Michelle Kilcoyne3,4,

Gerhard Schlosser5, Abhay Pandit1, Siobhan McMahon6

1 Centre for Research in Medical Devices (CÚRAM), 2Centre for Microscopy and Imaging, 3Carbohydrate Signalling Group, Microbiology, School of Natural Sciences, 4 Glycoscience Group, 5Zoology, 6Anatomy,

National University of Ireland, Galway [email protected]

Introduction:

Carbohydrates are widespread and play essential roles in the spinal cord (SC). For example, both

proteoglycans and glycoproteins are abundant in the extracellular matrix and glycoproteins are

critical components of the myelin sheath. It is well established that following injury to the SC

these matrix proteoglycans and myelin glycoproteins contribute to preventing regrowth and

repair. However the potential beneficial role of other populations of glycans has so far been

unexplored. The main aim of this study is to characterise the glycosylation pattern in SC in a

developmental model of Xenopus laevis, which is capable of regeneration as a tadpole, but loses

this ability following metamorphosis. Here we use stage 50 Xenopus laevis tadpole to study the

distribution of carbohydrates in the normal SC.

Methods:

Tissue cryosections (10 μm) were stained with a panel of FITC conjugated lectins. Low

magnification images were acquired with an Olympus IX81 fluorescent microscope with

Volocity™ acquisition software and higher power confocal images were acquired with an Andor

Revolution™ spinning disc confocal microscope.

Results:

The glycosylation profile in the spinal cord of Xenopus laevis tadpoles at developmental stage 50

is summarised in Table 1, with example images in Figure 1. The binding of each lectin displayed a

unique pattern showing that individual cellular features were differentially glycosylated.

Lectin Specificity Binding Intensity

White vs Grey Matter

Cellular vs Matrix

PNA Gal β(1,3)GalNac; Lactose, Gal β(1,4)Glucose

High Both Membranous / matrix

AIA D-galactose High Grey Cellular

DSA Β(1,4)GlcNAc Med Both Cellular (grey)

WGA Man β(1,4)GlcNAc β(1,4)GlcNAc Med Grey Cellular/nuclear

WFA GalNAc High Both Membranous / matrix


67

ConA High mannose structures High Both Membranous / matrix

SNA-I Sialic acid [α(2,6) linked] High Both Cellular (grey)

MAA Sialic acid [α(2,3) linked] High Both Cellular (grey)

ECA Terminal LacNAc structures, Galβ1,4GlcNAc Med Both Cellular (grey)

UEA-I α(1,2) linked fucose Med Both Cellular (grey)

PHA-E Complex oligosaccharides Med Grey Cellular

Table 1 Lectins used in this study along with their corresponding sugar epitopes and a brief description of their binding pattern.

Figure 2 Example of lectin reactivity in tadpole spinal cord. SNA-I binds α2,6 sialic acid, PHA-E binds complex oligosaccharides, ConA binds high mannose structures. Images were acquired using Andor spinning disc confocal

microscope.

Conclusion: The global glycosylation of the spinal cord of healthy Xenopus laevis tadpole has been profiled for the first time using lectin histochemistry.

Keywords: Lectin histochemistry, spinal cord injury, Xenopus laevis Acknowledgements: Funding support was provided thanks to European 7th Framework Programme, grant no. 304936. The authors acknowledge the Centre for Microscopy and Imaging, funded by NUIG and the Irish Government, for facilities, scientific and technical assistance.


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12. Optical properties of charged particle induced carbon profiles

Robert O’ onnell, Pierce Maguire, Yangbo Zhou, Hongzhou Zhang


Abstract: Charged particle induced contamination from residual precursors can have a

detrimental effect on the imaging and measurement of a specimen under observation in a

scanning electron microscope (SEM). However, these induced carbon profiles can be utilised for

2D and 3D direct writing and fabrication processes. Sample applications of this include etched

masks, atomic force microscope (AFM) super tips, insulating material for nano-junctions and

near-field optical sensors [1].

The profiles are primarily comprised of carbon and are induced during electron beam irradiation.

In terms of properties, they are similar to diamond like carbon (DLC) films. They are amorphous

in nature and their atomic structure is a mixture of sp2 (planar) and sp3 (tetrahedral) bonds [2].

The ratio of the sp2 to sp3 bonds in the profiles has an influence on their electrical, mechanical

and optical properties [3, 4]. The goal of this work is to characterise these carbon profiles in

terms of their sp2:sp3 bonding ratio, determine the key parameters which influence this ratio and

the effect of this ration on light scattering and the enhancement of Raman spectra.

Recent research on characterising carbon contamination in Raman spectroscopy and AFM [3]

reveals an enhancement of the ordered band (G-Band) in the film, the intensity of which

increased (non-linearly) with increased film thickness. Further research on films generated with

various electron beam energies (E0) showed that the sp3 fraction increased with E0 and resulted

in an increase elastic modulus and hardness [4]. Here we induce carbon profiles on a silicon

substrate, with increasing electron beam energies and studying characteristic Raman peaks for

silicon and carbon. This revealed an enhancement of the Si signal at ~520 cm-1 which correlated

to the profile thickness and its sp2:sp3 bonding ratio, given by the carbon peaks (Fig 1). The

bonding ratio and the crystallite size of the carbon clusters within the films, which are associated

with the enhancement effects, is determined by the position, intensity and intensity ratio of the

disordered (D) and ordered (G) carbon bands within the Raman spectra [5].

With an increase in sp3 fraction of amorphous carbon (a-c) films comes an increase in refractive

index, optical gap and electronic gap [2]. Therefore the tailoring of carbon nanostructures with

precise dimensions and sp2:sp3 bonding ratio, offers further application for induced carbon

profiles in the fields of carbon based electronics and enhanced Raman spectroscopy.


69

Figure 1: The enhancement in intensity of the characteristic Raman peak for Si (~520 cm-1) for carbon

profiles generated at both 1 keV and 5 keV, both of which were excited with 533nm laser energy. The

electron induced profiles were generated by a primary beam current of 32 and 35 pA for 1 keV and 5 keV

respectively over applied doses of 100 to 500 pC.um-2. This produced profile heights from 12 to 75 nm.

References: 1. Bret, T., et al., Characterization of focused electron beam induced carbon deposits from organic

precursors. Microelectronic Engineering, 2005. 78-79: p. 300-306. 2. Yoshikawa, M., et al., RAMAN-SPECTRA OF DIAMONDLIKE AMORPHOUS-CARBON FILMS. Journal

of Applied Physics, 1988. 64(11): p. 6464-6468. 3. Lau, D., et al., Electron-Beam-Induced Carbon Contamination on Silicon: Characterization Using

Raman Spectroscopy and Atomic Force Microscopy. Microscopy and Microanalysis, 2010. 16(1): p. 13-20.

4. W. Ding, D.A.D., X. Chen, R.d. Piner, R.S. Ruoff and E.Zussman., Mechanics of hydrogenated amorphous carbon deposits from electron-beam-induced deposition of a paraffin precursor. Journal of Applied Physics, 2005. 98(1): p. 014905.

5. Robertson, J., Diamond-like amorphous carbon. Materials Science & Engineering R-Reports, 2002. 37(4-6): p. 129-281.


70

13. Application of a rolled-sheet fabrication technique to improve full-thickness cellularisation

of nanofibrous tissue-engineered vascular grafts

Woods, I., Ho, N.X., Flanagan T.C.

School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland

Electrospun nanofibrous scaffolds are routinely used to mimic the extracellular matrix (ECM)

structure of native arteries in tissue-engineered vascular graft (TEVG) development [1]. However,

condensed packing of these nanofibres prevents homogenous cell permeation, which can lead to

poor tissue development and potentially graft failure [2]. This study aimed to compare the

cellularisation and tissue properties of surface-seeded tubular TEVG scaffolds versus those

prepared by a rolled-sheet fabrication technique, and to determine how changes in sheet

material and fibre orientation affect cellular orientation and ECM synthesis.

Four groups of nanofibre scaffold (tubular, unaligned sheets, aligned sheets, bilayered sheet)

were produced by electrospinning polycaprolactone, with fibrinogen incorporated to form the

bilayered sheet (each n=6). Tubular scaffolds and unaligned sheets were seeded with human

dermal fibroblasts (HDFs) for 1-week to proof the rolled-sheet fabrication, in addition to

measuring tensile properties. Aligned/bilayered sheets were cultured separately for 10 days to

allow for increased ECM development. Immunofluorescence microscopy and quantitative dye-

binding assays were performed on all groups to examine ECM synthesis and cellularisation.

Immunoflourescence staining revealed an even cell distribution throughout concentric layers of

rolled scaffolds and abundant synthesis of ECM constituents; in contrast, sparse cell distribution

and minimal ECM were evident in tubular scaffolds. Tensile testing revealed a maximum stress of

1.3MPa for both groups tested. Aligned scaffolds were shown to influence cellular and ECM

orientation. Furthermore, the addition of fibrinogen to produce a bilayer-composite enhanced

cell proliferation (3.91±1.27x10⁶ to 7.18±1.07x10⁶ cells per 5-mm section), while elastin synthesis

increased significantly from 4.81±1.07mg/g to 12.69±1.27mg/g tissue.

The present study demonstrates substantial improvement in the cellularisation of electrospun

scaffolds by rolling pre-seeded cell sheets into a tubular configuration as TEVG scaffolds. The

preservation of mechanical properties, and tailoring of morphology and tissue synthesis, can

have significant implications for development of living, biomimetic vascular grafts using

electrospinning.

Keywords: tissue engineering, vascular graft, electrospinning, cell seeding.

References:

[1] Woods I, Flanagan T (2014) “Electrospinning of biomimetic scaffolds for tissue-engineered vascular grafts: threading the path” Expert Review of Cardiovascular Therapy, 12(7): 815-32.

[2] Soliman et al. (2011) “ ontrolling the porosity of fibrous scaffolds by modulating the fiber diameter and pac ing density” ournal of Biomedical Materials Research Part A, 96( ): 566-74.

Acknowledgements:The authors acknowledge funding provided by the National Children’s Research

Centre/Children’s Medical & Research Foundation, and also through the Wellcome Trust Biomedical

Vacation Scholarship Scheme.

http://www.tandfonline.com/doi/abs/10.1586/14779072.2014.925397

http://www.tandfonline.com/doi/abs/10.1586/14779072.2014.925397

http://www.tandfonline.com/toc/ierk20/12/7


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14. The structure of the inkjet printed layers and their electrical properties

Cian Nash1, George Amarandei1, Ian Clancy1, Bartlomiej Andrzej Glowacki1,2,3

1 Department of Physics and Energy, Bernal Institute, University of Limerick, Limerick, Ireland 2 Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road,

Cambridge CB3 0FS, England, United Kingdom 3 Institute of Power Engineering (IEn) ul. Mory 8, 01-033 Warsaw, Poland

Printing flexible electronics has been undergoing enhanced development over the last decade.1

Direct coating methods using metal particles deposited from aqueous solutions or solvent-based

inks is central in roll-to-roll fabrication processes, these methods can produce continuous or pre-

defined conductive layers on a large variety of substrates.1-3 However, understanding and

controlling the physical processes have not exhibited a similar trend. These physical processes

are complex and require not only predicting the ink fluid dynamics as a whole but also

understanding the behaviour of the particle dynamics during printing. The electrical conductivity

of the printed layers is determined by the degree of particle compaction and their ability to form

a conductive path or layer. Inkjet printing of silver and/or carbon based inks is a promising route

for the manufacture of electrically conductive layers and coatings on almost any substrate. In this

study the effect of the inkjet printing parameters, ink composition, particle properties and/or

thermal treatment on the conductivity of the printed layers is investigated. The micro and

nanostructure of printed layers is investigated by optical and electron microscopy and used to

explain the observed changes in electrical conductivity of the printed layers.

Keywords: Inkjet Printing, Silver, Carbon

References: 1, Nash C., Spiesschaert Y., Amarandei G., Stoeva Z., Tomov R.I., Tonchev D., van Driessche I., Glowacki

B.A., Journal of Electronic Materials, 44 (2015), 497-510 2 F.C. Krebs, Sol. Energy Mater. Sol. Cells, 93 (2009) 394-412 3 Hutchings I. M., Martin G. D. Inkjet Technology for Digital Fabrication, 2013 John Wiley & Sons Ltd


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15. Diffraction Contrast Effects in CuInGa(S1-xSex)2 Semiconductor Nanocrystals

Claudia Coughlan1, Yina Guo1, Ajay Singh 2,3, Shalini Singh 1, Shohei Nakahara1 , Kevin M. Ryan2*

1. Materials and Surface Science Institute and Department of Chemical and Environmental Sciences, University of Limerick, Limerick, Ireland

2. The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA 3. Department of Chemical Engineering, The University of Texas, Austin, Texas, 78712

Colloidal synthetic routes to ternary and quaternary copper-based nanocrystals hold significant

promise for thermoelectric and photovoltaic applications, where their solution processability

combined with size dependent properties offers considerable advantages over bulk routes to

these materials.1,2 Herein, we report on the formation of colloidal CuInGa(S1-xSex)2 (CIGSSe)

nanocrystals that adopt a novel 2D nanoplate morphology and crystallize in the metastable

wurtzite phase.

A detailed electron microscopy analysis reveals that the 2D nanoplates experience bending on

the (0002) plane, as evidenced by the presence of regular dark fringes in bright field TEM images.

These dark fringes are diffraction contrast effects known as bending contours and occur due to

angular variations existing between the (0002) atomic planes and the direction of the incident

electron beam. Each nanoplate displays distinctive star-like fringes and well-defined crossing

points, with the splitting of the contours easily identifiable and consistent for each nanocrystal.

The observation of bending contours is further supported through TEM tilting experiments and

displaced aperture dark field images to identify the principal dark bend contours, as well as

HRTEM, HAADF-STEM and SEM images of the lateral sides of the nanoplates. Furthermore, TEM-

EDS line scans and maps were carried out to determine the chemical composition distribution in

the nanoplates. It was found that the presence of a surfactant used in the synthesis,

trioctylphosphine oxide, induces the formation of buckled nanoplates and causes dramatic

changes in the internal crystal structure, which lead to the creation of non-regular stacking faults

buried in the nanoplates.

Keywords: CIGSSe, bending contours, bent nanoplate

References: 1 Aldakov, D.; Lefrancois, A.; Reiss,P. J. Mater. Chem. C 2013, 1, 3756-3776. Vvvvvvvvvv

v2 Coughlan, C.; Singh, A.; Ryan, K.M. Chem. Mater. 2013, 25, 653-661.


73

16. Generation and characterisation of novel antibody fragment molecules for specific

detection of Neu5Gc on tissues

Sharma, R. K., Cunningham, S., Kilcoyne, M., Kane, M., Joshi L.

Glycoscience Group, National Centre for Biomedical Engineering Sciences,

National University of Ireland Galway, Ireland.

N-glycolylneuraminic acid (Neu5Gc) is a nine carbon sugar from the sialic acid family which is

presented as a terminal sugar on the glycan chains of cell surface glycoconjugates and on

individual glycoproteins of most mammals, with the exception of man. During evolutionary

development a single point mutation in the gene CMAH encoding cytidine monophosphate-N-

acetylneuraminic acid hydroxylase, an enzyme responsible for converting Neu5Gc from its

precursor N-acetylneuraminic acid (Neu5Ac) rendered it inactive in man.

However, in an interesting turn of events, Neu5Gc has been reported to be frequently expressed

by a number of human cancers [1]. Presenting Neu5Gc as a potential biomarker for cancers

diagnosis. The detection of this glycan epitope, would provide greater information from both

patient sera and direct tissue biopsies used for imaging and diagnosis of cancer. Currently,

polyclonal anti-Neu5Gc antibodies isolated from immunised chickens are utilised for Neu5Gc

imaging in tissues [2]. However, polyclonal antibodies have variable affinity and cannot be

produced with consistent quality. Lectins, have also proven unsuited for clinical histological

detection of Neu5Gc. Therefore, a need for a high affinity, high specificity molecule to permit the

further use of Neu5Gc as a histological marker exists.

Utilising phage display technology, we report, the identification of monoclonal single chain

antibody fragments (scFv) generated from immunised chickens scFv libraries. Anti-Neu5Gc scFv

have been subsequently screened, characterised and applied to clinical samples, sera and tissue,

for the detection and measurement of Neu5Gc. We will present the current state of these

molecules and demonstrate their potential for clinical histological applications.

Keywords: Cancer imaging, anti-Neu5Gc scFv, N-glycolylneuraminic acid.

References: 1. Samraj, A.N., et al., Involvement of a non-human sialic acid in human cancer. Frontiers in

oncology, 2014. 4. 2. Diaz, S.L., et al., Sensitive and specific detection of the non-human sialic Acid N-

glycolylneuraminic acid in human tissues and biotherapeutic products. PLoS One,

2009. 4(1): p. e4241-e4241.


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17. Microstructural changes in heat treated Ti-rich NiTi shape memory alloy

Ghazal Tadayyon1,2, Yina Guo3, Seyed Mojtaba Zebarjad1*, Mohammad Mazinani1, Syed A. M.

Tofail3 and Manus J. Biggs2

1, Department of Material Science and Engineering, Engineering Faculty, Ferdowsi University of Mashhad, Iran

2, Network of Excellence for Functional Biomaterials, National University of Ireland, Galway 3, Materials and Surface Science Institute, University of Limerick, Limerick, Ireland

Martensitic evolution in Ti-rich NiTi alloy, Ti50.5Ni49.5, has been investigated as a function of

annealing, solution treatment and a combination thereof and a detailed electron microscopic

investigation carried out. Self-accommodated martensite plates resulted in all heat treated

samples. Martensitic <011> type II twins, which are common in NiTi shape memory alloys, were

found in both, as-received and heat-treated samples. Solution treated samples, additionally,

showed {11-1} type I twinning, which was also found in samples that have been annealed after

solution-treatment. Another common feature of the microstructure in both, as–received and

heat treated samples is the formation of Ti2Ni precipitates. The size, number and dispersions of

these precipitates can be controlled by resorting to a suitable heat treatment e.g. solution

treatment.

Keywords: NiTi shape memory alloy, Microstructural evolution, Annealing, Solution treatment


75

18. Characterising the Interaction of Diffusion Braze with Welded and Single Crystal Nickel-

Based Superalloy Substrates Using SEM and EBSD

E. Hinchy1,2, M. J. Pomeroy1,3, D. A. Tanner1,2.

1. Materials and Surface Science Institute, University of Limerick 2. Department of Design & Manufacturing Technology, University of Limerick.

3. Department of Civil Engineering and Materials Science

Aero-engine nickel-based superalloy turbine components undergo thermal mechanical fatigue

cracking during service, and are typically repaired using diffusion brazing[1,2]. Frequently,

diffusion braze is applied to welded substrates – a practice which is not reported on in the

literature. In this work, Scanning Electron Microscopy (SEM) backscattered electron imaging,

Energy Dispersive Spectroscopy (EDS), and Electron Backscattered Diffraction (EBSD) techniques

are used to characterise two different weld types, namely Tungsten Inert Gas (TIG) and

Superalloy Welding at Elevated Temperatures (SWET), as well as a Single Crystal (SX) substrate.

EBSD mapping confirmed that TIG weld seams grew epitaxially from the SX substrate, with

randomly orientated grains located towards the crown of the weld. The welds produced by SWET

had an entirely columnar microstructure, but contained colonies with common crystallographic

orientations, with inter-dendritic voiding observed in the crown of each weld. Two wide-gap

diffusion braze materials with two different concentrations of boron melting point depressant

were applied to the three substrate types. Using backscattered electron SEM imaging and EDS, it

was observed that the braze diffusion zone of the SX substrate consisted of discrete boride

particles, whose density and depth of penetration from the braze interface increased with

increasing boron concentration. The TIG welded microstructure showed an increase in boron

diffusion for both braze types when compared to the SX substrate, primarily due to the number

of grain boundaries at the weld-braze interface. The voiding observed in the crown of the weld

produced by SWET was completely infiltrated by both braze materials, increasing the expected

mechanical strength of the weld. Boron interaction with hafnium-tantalum-carbides in the

welded substrates led to the formation of deleterious needle-like carbo-boride phases in both

weld types. Increasing the boron concentration of the surface braze led to denser precipitation

of borides and carbo-borides in all three substrate types, potentially reducing mechanical

properties.

Keywords: EBSD, SEM, Nickel-Based Superalloys, Diffusion Brazing, Welding

References:

1, Xia, P. C., Chen, F. W., Xie, K., Qiao, L., & Yu, J. J. (2015). Influence of microstructures on thermal fatigue

property of a nickel-base superalloy. Frontiers of Materials Science, 1-8.

2, Huang, X., & Miglietti, W. (2012). Wide gap braze repair of gas turbine blades and vanes—a review.

Journal of Engineering for Gas Turbines and Power, 134(1), 010801.


76

19. Seeing the whole picture- advantages and shortcomings of EFTEM

U. Bangert1, W. Pierce2, C. Boothroyd3

1, Department of Physics and Energy, University of Limerick, Limerick, Ireland 2, School of Materials, The University of Manchester, Manchester M13 9PL, UK

3, Ernst Ruska Centre for Microscopy and Spectroscopy with Electrons, Research Centre Juelich, D-52425 Juelich, Germany

Electron energy loss spectroscopy in scanning mode tends to be the preferred way to acquire

energy loss data. Data cubes obtained from Spectrum Images (SIs) contain an entire spectrum in

each defined image pixel. Evaluation of such data is relatively fast and straight-forward, as it is

‘spectrum controlled’, hence post-acquisition energy alignment and intensity calibration of

specific loss features can be easily carried out without further calibration measurements. The

acquisition of SIs is, however, slow, and due to the high beam currents of the focussed probe

changes in sample morphology are often induced, even with short acquisition times, especially in

2-D and 1-D materials. So energy loss mapping based on SIs, although providing great energy

resolution, is mostly restricted to small areas.

Energy filtered imaging (EFTEM) on the other hand provides energy loss images of large areas, at

the same time enabling sequential images (data cubes) to be taken with energy steps in the meV

range. EFTEM imaging is fast and less destructive then spectrum imaging, due to the lower beam

intensity. It presents, however, difficulties in the evaluation and interpretation of EFTEM data,

due to non-isochromaticity and afterglow effects. Whereas this does not affect the core loss

region so much because the energy resolution here is usually in the eV range and the spectral

region is remote from the intense low loss region, it poses significant shortcomings for the data

acquisition in the latter.

Here we show highly localised EFTEM results obtained in nano-materials, in particular of

excitations in the uv/vis energy region in graphene, and how particular spectral features and

confinement/ enhancement thereof relates to the nanotopography. The results were obtained

after applying correction routines regarding isochromaticity, dark current variations and

afterglow effects.

Keywords: EFTEM, low loss EELS, graphene


77

20. Bacteria that travel: biofilm in aircraft water systems

Harald Handschuh and Catherine Adley

Microbiology Laboratory, Department of Chemical and Environmental Sciences, University of Limerick, Limerick, Ireland.

Microorganisms in low nutrient (oligotrophic) environments e.g. water face several options for

survival: they can form spores or develop a biofilm, both starvation survival mechanisms. Some

microorganisms e.g. Ralstonia pickettii survive in high purity water1. Management and control of

biofilm is of grave importance in multiple industries including pharma2, food, petroleum, medical

instrumentation (dialysis, analyzers) and all water streams. In this study a total of 80 positively

identified organisms were collected from aircraft galleys, the water service vehicle and the water

collecting point, and a phylogenetic tree of relativeness constructed. The development of biofilm

was determined using a borescope and in vitro biofilm developed and viewed microscopically

(SEM) for detection and monitoring of control of water contamination in aircraft water tanks.

Figure 1: Water diatom trapped by biofilm

Keywords: biofilm, potable water.

References: 1. Adley CC, Ryan MP, Pembroke JT and Saieb FM (2005) Ralstonia pickettii in high purity water. In

Biofilms:Persistance and Ubiquity. Eds. Mc Bain A., Allison D., Pratten J., Spratt D., Upton M., and Verran J. pp261-272. Biofilm Club [ISBN: 0-9551030-0-2]

2. PDA Technical Report No 69 (2015) Bioburden and Biofilm Management in Pharmaceutical Manufacturing Operations. Parenteral Drug Association Inc. Washington, US. ISBN: 978-0-93-

945976-6


78

21. Lithium Alloying Nanostructured Anodes with High Capacity and Power Performance

Tadhg Kennedy, Michael Brandon, Emma Mullan, Kevin M Ryan

Materials and Surface Science Institute and Chemical and Environmental Sciences Department, University of Limerick

Ge nanowires (NWs) are a promising anode material for next generation lithium-ion batteries

due to their large maximum theoretical capacity (1385 mAh/g) when compared with

conventional graphitic based materials (372 mAh/g). NWs also provide good electrical

conductivity along their length, have a high interfacial area in contact with the electrolyte, have

an optimal short diffusion distance for Li-ion transport and can be grown directly from current

collectors, eliminating the need for binders and conductive additives. Here we demonstrate

stable cycling over 1100 cycles of Ge NWs grown directly from a current collector. We show by

ex-situ high-resolution transmission electron microscopy (HRTEM) and high-resolution scanning

electron microscopy (HRSEM) studies that the NW array transforms into a robust porous network

structure within the first 100 cycles. Once this network is formed it is highly stable, maintaining a

capacity of 900 mAh/g over the following 1000 cycles. The electrode material described here

has several advantages as it is formed in a low energy, wet-chemical process with Ge NWs

nucleating and growing from an evaporated Sn layer on stainless steel. Sn also has a high

maximum theoretical capacity (994 mAh/g), and we show both physically (TEM) and

electrochemically (differential capacity) that the Sn seeds at the ends of the NWs reversibly alloy

with lithium and contribute to the electrodes overall specific capacity. The NW electrode

architecture also performed exceptionally well in rate capability tests achieving a discharge

capacity of 435 mAh/g after 80 cycles at a discharge rate of 100C.

Figure 1: Graph showing the discharge capacity of a Ge nanowire anode cycled over 1100 cycles. The inset

schematic illustrates the transformation process that occurs as a result of cycling with the nanowire

morphology transforming into a porous network of ligaments.

Keywords: nanowire; lithium-ion battery; germanium; high-capacity


79

22. In Situ TEM Characterisation of 2-Dimensional Materials in Liquids for Energy Storage and

Optoelectronics Applications

Evie Doherty1,2,3, Andrés Seral-Ascaso1,2,3, Eva McGuire1,2,3, Valeria Nicolosi1,2,3

1, School of Chemistry Trinity College Dublin 2, CRANN (Centre for Research on Adaptive Nanostructures and Nanodevices), Trinity College Dublin

3, AMBER (Advanced Materials and BioEngineering Research Centre), Trinity College Dublin

The demands of modern energy consumption present new challenges regarding the storage of

electrical and chemical energy. Traditional materials for creating batteries and capacitors can be

examined in new ways with a view to increasing their efficiency and lifetime, whilst minimising

device size. Research has shown that the use of 2-dimensional (2D) versions of traditional energy

storage materials can deliver significant advances in energy-storage technology [1]. However the

use of, and interactions of these materials with one another, is still not well understood. One

challenge to date has been how to image liquid-dispersed materials and their chemical

interactions in situ. With the advent of a new generation of Liquid-Cell TEM holders, it is possible

to conduct electron microscopy studies on 2D materials dispersed in liquid, thus presenting a

new range of experimental conditions for better understanding material interactions and

processes.

Using a Hummingbird Scientific Liquid-Cell TEM Holder in both CTEM and STEM modes, we have

studied a diverse range of 2D materials using a variety of liquids and liquid electrolytes. We can

observe the behaviour of materials as they interact with liquids and the electron beam. Imaging

can be carried out in both static and dynamic liquid environments and specimens are observable

on nanometre scales and with crystal-lattice resolution. Materials we have studied include

elemental 2D materials, transition metal dichalcogenides, metal-oxides and composites. These

data can then be compared with macro-scale ex situ measurements of these materials [2, 3]. This

information can deepen our understanding of the interactions for a whole range of 2D layered-

nanomaterials. It can also open the possibility of optimising existing battery and super-capacitor

materials and discovering new, inexpensive and perhaps renewable materials for use in energy-

storage technology.


80

Figure 1: 2-Dimensional flakes in water being imaged inside a Liquid Cell Holder using Conventional TEM

Keywords: Liquid-Cell TEM, Energy Materials, 2D Materials

References: [1] Arico, A.S., et al., Nanostructured materials for advanced energy conversion and storage devices. Nat

Mater, 2005. 4(5): p. 366-377.

[2] Mendoza-Sanchez, B., et al., Scaleable ultra-thin and high power density graphene electrochemical

capacitor electrodes manufactured by aqueous exfoliation and spray deposition. Carbon, 2013. 52 p. 337-

346.

[3] Mendoza-Sanchez, B., et al., An investigation of nanostructured thin film alpha-MoO3 based

supercapacitor electrodes in an aqueous electrolyte. Electrochimica Acta, 91 p. 253-260

[4] The authors gratefully acknowledge funding from the European Research Council, Science Foundation

Ireland and the Advanced Materials and BioEngineering Research Centre.


81

23. ‘Under the Microscope’ - A Microscopy Outreach Pilot Programme

Kerry Thompson1,2, Alanna Stanley1, Yvonne Lang1, Peter Dockery1,2

1. Centre for Microscopy and Imaging, Anatomy, School of Medicine, National University of Ireland

Galway.

2. Anatomy, School of Medicine, National University of Ireland Galway.

Abstract:

This pilot programme was carried out between January and June 2015 and aimed to promote

and explore core Science, Technology, Engineering, & Maths (STEM) skills for children in rural

primary schools, in a fun and educational environment using the Royal Microscopy Society’s

(RMS) Microscope Activity Kits (MAK’s). The ‘Under the Microscope’ team, in collaboration with

the RMS, began the programme with funding secured through the NUI Galway staff and student

collaborative initiative EXPLORE (http://www.su.nuigalway.ie/explore-home). Since it was

launched, 4 rural schools in county Galway and 1 in county Mayo were visited by ‘real life

scientists’ to set up and demonstrate the kits to both students and primary school teachers. Each

of the schools visited kept the kit for a minimum of 4 weeks, allowing over 450 primary school

students to have access to a microscope on a daily basis for this period. This poster presents

information about the MAK’s and feedback collected over the course of the programme.

Keywords: Microscopy, Outreach, Education, Primary School, Science


82

Delegate List

Full name Company / Organisation Email Address

Catherine Adley University of Limerick [email protected]

Savyasachi Aramballi Jayanth Trinity College Dublin [email protected]

Paul Arnold FEI [email protected]

Ursel Bangert University of Limerick [email protected]

Mark Berrisford Zeiss [email protected]

Alexander Black NUI Galway [email protected]

Brian Caffrey University College Dublin [email protected]

Ashvin Cherodian NT-MDT [email protected]

Chuan Wei Chung Bruker [email protected]

Clair Collins Tescan [email protected]

Elizabeth Conway Analog Devices [email protected]

Jennifer Cookman University College Dublin [email protected]

Michele Corrigan University of Limerick [email protected]

Claudia Coughlan University of Limerick [email protected]

Mark Croke Thermofisher Scientific [email protected]

Dominique Delille FEI [email protected]

Calum Dickinson JEOL [email protected]

Keith Dicks Oxford Instruments [email protected]

Evie Doherty Trinity College Dublin [email protected]

David Doran Analog Devices [email protected]

Anwesha Fernandes University of Limerick [email protected]

Marc fernandez NUI Galway [email protected]

Michael Flynn Analog Devices [email protected]

Grace Flynn University of Limerick [email protected]

Tom Fogarty Analog Devices [email protected]

Daniel Fox Trinity College Dublin [email protected]

Graeme Gibbons Lambda Photometrics [email protected]

John Gilbert Bruker [email protected]

Satbir Gill NUI Galway [email protected]

Matthew Gleeson University of Limerick [email protected]

John Gordon University College Dublin [email protected]

Sarah Guerin University of Limerick [email protected]

Yina Guo University of Limerick [email protected]

Alan Harvey University of Limerick [email protected]

Katie-Jo Harwood Ulster University Jordanstown [email protected]

Patrick Healy Mason Technology [email protected]

Eoin Hinchy University of Limerick [email protected]

Darren Horan Zeiss/Labquip [email protected]

Lekshmi Kailas University of Limerick [email protected]

Maryam Karimijafari University of Limerick [email protected]

Roisin Kelly Tyndall [email protected]

Tadhg Kennedy University of Limerick [email protected]

Patrick Kissane Kostal [email protected]


83


Mahendar Kumbham University of Limerick [email protected]

Martin Leahy NUI Galway [email protected]

Ning Liu University of Limerick [email protected]

Amy Danielle Lynes Trinity College Dublin [email protected]

Pierce Maguire Trinity College Dublin [email protected]

Patrick Marks Hitachi [email protected]

Kieran McDermott University of Limerick [email protected]

Paul McKeown Kostal [email protected]

Cian McKeown University of Limerick [email protected]

Pamela Meade NT-MDT [email protected]

Kevin Meade Oxford Instruments [email protected]

Cian Nash University of Limerick [email protected]

Hannah Nerl Trinity College Dublin [email protected]

Maarten Nijland University of Twente [email protected]

Maria O'Brien Trinity College Dublin [email protected]

Eoghan O'Connell University of Limerick [email protected]

Robert O'Connell Trinity College Dublin [email protected]

Jenny O'Connell Mason Technology [email protected]

Noel O'Dowd University of Limerick [email protected]

John O'Flynn VWR [email protected]

Tiina O'Neill University College Dublin [email protected]

Michael Pomeroy University of Limerick [email protected]

Lorraine Quinn University of Limerick [email protected]

Ramesh Raghavendra Waterford Institute of Technology [email protected]

John Reidy Bio Sciences [email protected]

Jan Ringnalda FEI [email protected]

John Rodenburg University of Sheffield [email protected]

Fiona Rogan Ulster University Jordanstown [email protected]

Colm Ronan Analog Devices [email protected]

Rachel Ronan NUI Galway [email protected]

Toby Scrivener Laser 2000 [email protected]

Rajesh Kumar Sharma NUI Galway [email protected]

Martin Sheehan University of Limerick [email protected]

Aleksey Shmeliov Trinity College Dublin [email protected]

Shalini Singh University of Limerick [email protected]

Dalibor Soukup Keele University [email protected]

Aimee Stapleton University of Limerick [email protected]

Martin Steer University College Dublin [email protected]

Odile Stéphan Université Paris-Sud [email protected]

Chris Stephens Thermofisher Scientific [email protected]

Andrew Stewart University of Limerick [email protected]

John Synnott Bio Sciences [email protected]

Marta Szubert VWR [email protected]

Ghazal Tadayyon University of Mashhad/NUIG [email protected]

David Tanner University of Limerick [email protected]

Kerry Thompson NUI Galway [email protected]


84


Alberto Tinti FEI [email protected]

Juliet Twohig Analog Devices [email protected]

Emma Veale Trinity College Dublin [email protected]

Kevin Walker Oxford Instruments [email protected]

Stephan Werk Lavision Biotec [email protected]

Paul Whitford Keyence [email protected]

Ian Woods University College Dublin [email protected]

Fengshi Yin University of Limerick [email protected]

Heath Young LOT Quantum Design [email protected]

HongZhou Zhang Trinity College Dublin [email protected]

Yangbo Zhou Trinity College Dublin [email protected]


85

We would also like to thank our exhibitors for their contribution to this year’s symposium.

Exhibitors

university of limericksymposia.microscopy.ie/msi2015/doc/msi2015.pdf · dr. david cottell, retired...

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