empanews january 2012

What’s going on inthis NEST? 14

Bio-tuning forexcellent sound 04

“Steam blasting”with real gold 22

Magazine for Research, Innovation and Technology TransferVolume 10 / Issue 35 / January 2012

EmpaNews

Smart buildings

02 // Editorial

Bio-tuning for excellent soundA fungus endows new violinswith Stradivari’s magic 04

Research for thecommon good

This has been our trademark for more than 120years. A tie made of 24 carat gold, in contrast,hardly fits that bill. Even so, this luxury accesso-

ry for the well-to-do man (also availableon loan to the author) is a perfect exampleof technology transfer “à la Empa”.What’s at issue here is not simply friv-olous neckwear, but rather the plasmatechnology process developed at Empa,which for the first time makes it possibleto put an ultra-thin coating on thread. It’suseful for the manufacture of antibacterialmedical textiles for the operating room,for electrically conductive fibres, and soon and so forth... Hence, the gold tie is

just a “by-product”. With a retail price of CHF 7,500quite an expensive one, though.

At first glance, too, the world’s smallest electric car,measuring only 4 x 2 nanometres, is simply a technicalgimmick, perhaps best described as playing molecularLego bricks. Truly useful innovations are a differentballpark altogether, you might think. But hold yourhorses! It’s experiments like these that offer scientists afundamental understanding of the behaviour of mater-ials and surfaces. This knowledge, in turn, is exactlywhat we need to develop new materials with improvedproperties, for instance optimised membranes for bat-teries or more efficient coatings for solar cells. In otherwords, basic research such as mentioned here is the en-gine driving innovation, the fertile soil of sorts, in whichinnovative technologies can take root and thrive.

There are more tangible examples in this issue’s Focussection, in which we venture a glimpse into the futureof buildings. And we’re really thinking big here: with“NEST”, our visionary “building lab”, we hope to donothing less than invent the future – at least the one wewant to live in.

Enjoy your reading!

Michael HagmannHead Communications

Cover

Buildings are here to stay for quitesome time – and thus are not wellsuited for short-term experiments.With its “NEST” building lab, Empaintends to solve this problem;it consists of a reinforced concrete back-bone – a docking station of sorts –,upon which innovative residentialand office modules will be installed.In NEST, visionary building conceptscan prove their value in everyday use.

Contents // 03

CT scans for industryThe mysterious inner lifeof things 22

Sensor technology on a brick wallRenovating older buildings ina rugged lab test 18

The world’s smallest electric car Test-driving a single moleculewith 4-wheel drive 07

Research and development04 Instruments from the fungus laboratory Bio-tuning gives new violins the sound of a true Stradivarius

07 The world’s smallest electric car A 4-wheel test drive in a scanning tunnelling microscope

08 Muscles made of plastic Mass production replaces handmade prototypes

Focus: Smart buildings

10 Experiments with buildings? NEST makes it possible! Empa’s modular building research platform to open in 2012

14 What’s going on in this NEST? 21st century building technology – explained in five visions

16 Put the summer sun in concrete Seasonal thermal storage inside walls

17 And now the forecast … Using computers to predict material properties of concrete

18 A good insulation pays off Renovating older buildings with high-tech materials

20 A window for any occasion Electrically switchable windows – a vision for the near future

Knowledge and technology transfer21 “Steam blasting” with real gold Shiny threads for haute couture through plasma coating

24 This way, please! The glaTec technology centre as a start-up incubator

Science dialogue26 Taking a peek inside Industrial computer tomography at Empa

Imprint

PublisherEmpaÜberlandstrasse 129CH-8600 DübendorfSwitzerlandwww.empa.ch

Text & DesignCommunication

ContactPhone +41 58 765 47 [email protected]

Published quarterly

ISSN 1662-7768

04 // Research and development

Which budding talent doesn’tdream of just once being able toplay on a Stradivarius, the ultim-

ate in the arts and crafts of violin making?As we all know, these instruments are fewand far between and unaffordable for justabout everyone. Modern violins with com-parable sound qualities would be very wel-come. Empa researcher Francis Schwarzehas created one together with a Swiss vio-lin maker – and with the help of the wood-rot fungi Physisporinus vitreus, which se-lectively breaks down certain structures inwood, thereby considerably improving itsresonance properties.

Applying it in a controlled manner, thefungus “attacks” conifer wood and gives itstructural properties similar to the woodused to make musical instruments in thelate 17th and early 18th centuries. Thiswood grew during the “Maunder Mini-mum”. The climate at that time – long,

hard winters and cool summers – lad toslower growth, narrow and more uniformannual rings and lower density. Schwarzehas had several “fungus violins” producedfrom the biotech-treated wood, and theirsound was clearly preferred to paired “nor-mal” contemporary instruments. Theyeven exceeded expectations when com-pared to a historical violin. At a symposiumin 2009, two “fungus violins” went upagainst a Stradivarius in a blindfold listen-ing test. The expert jury and the audiencefound their sound more pleasing than theinstrument made by the Italian master fromCremona.

Generous financial support from theWalter Fischli FoundationTo enable sufficient numbers of such violinsto be crafted with fungus-treated tonewood,Schwarze has developed a standardisedbiotech process. To continue the fungus vio-

Instruments from thefungus laboratory A blindfold listening test in front of a panel of experts shows that violins made ofwood treated with fungus need not take a second seat to a Stradivarius. However,these modern day “miracles of sound” have, up to now, only been crafted asa handful of individual specimens. To produce more of these biotech violins,researchers are working on optimising and standardising the techniques for fungaltreatment of tonewood. In this they’ve found a new financial backer in the WalterFischli Foundation.

TEXT: Martina Peter / PICTURES: Christian Grund (13 Photo) , Empa , zVg

www.worldradio.ch/wrs/news/switzerland/stradivarius-squares-off-against-fungi.shtmlFor smartphone users: scan the QR code(e.g. with the “scanlife” app)

Podcast:Bio-tuning forexcellent sound

1Francis Schwarze checks thesound of a violin in his funguslaboratory.

2Project leader Iris Brémaudexamines wooden blanks inthe climate chamber andchecks on the work beingdone by the violin maker’sbiological assistant.

2

1

Research and development // 05

>>

lin project, he has found a new financial sup-port in Walter Fischli, the founder of thebiotech company Actelion, or to be more pre-cise, his foundation. Fischli, an enthusiasticamateur violinist, plans to support Schwarzefinancially because the project combines histwo “passions” – science and music (see inter-view p. 6). An interdisciplinary project, whichstarted in September and is intended to runfor three years, is attempting to develop a de-fined and controlled wood-treatment process.

The project is being led by Iris Brémaud.Not only is she an expert in the properties ofinstrument wood, she is also passionate forthe techniques and history of musical instru-ments, played music herself, and learned howto make classical guitars and lutes in an Eng-lish musical instrument workshop. Her pas-sion for the diversity of wood properties andinstruments even took her to Japan. “Therange of sounds of music there is completelydifferent than in European music”, she ex-

plains. “That is related to the fact that in Asiahardwoods are often used to make sound-boards of traditional instruments, whereas inEurope conifer wood is preferred.” In the nextfew years, she will study wood from spruceand maple trees in greater depth. For her, it’sclear that working with the wood-rot fungusis very enlightening in order to better under-stand which wood structures and compo-nents determining tonal properties.

Interdisciplinary collaboration As project partner, Brémaud and Schwarzeteamed up with violin maker Michael Baum-gartner, who in his studio in Basel is in thethird generation of artisans making string in-struments. However, countless tests on un-treated and treated wood samples must be car-ried out before he can get his first fungus-treat-ed-wood. One of Brémaud’s tasks is to find outin a first phase which wood samples appear tobe suited for further use in violin making.

For her studies, Brémaud can count onthe interdisciplinary support of a largenumber of colleagues at Empa. Ultrasoundexpert Jürg Neuenschwander, for example,is using a method based on air-coupled ul-tra-sound, a technique which was only justrecently developed as part of a PhD thesis,to study the distribution of acoustic vel-ocity and attenuation. The method, whichis currently used to detect poorly gluedspots in laminates, could also be employedto determine in which areas the rot funguswas active and where it was not. ErwinHack, an expert for optical measurementtechniques, is also on board. He measuresthe deformation patterns of wood plates asthey vibrate, which is in the range of a fewmicrometres, and to do so he uses laserspeckle interferometry. With this methodhe can describe how various types oflutherie wood and even complete instru-ments radiate acoustically. //

06 // Research and development>>

Empa is resuming its “fungus violin” project. Its goal isto develop a standardised process for the fungal treat-ment of wood to manufacture violins and other musicalinstruments. The continuation was made possible bythe Walter Fischli Foundation who is financing the pro-ject’s second phase.

A biochemist and biotech entrepreneur such asyourself and a research project dealing with woodfor manufacturing violins – this doesn’t seem like anatural fit. How did it come about that your Foun-dation is supporting this Empa project?

Walter Fischli: I first heard about this exciting fungusviolin project in the media. Because I’m a biochemist, playthe violin and have a special interest in large Italian in-struments, I called Francis Schwarze out of pure curiosity.During the very first conversation I learned that, eventhough the results were very promising, the project couldnot be continued for financial reasons. I believe it wouldhave been unforgiveable to let this interesting project,which combines science and violin making in an idealway, simply fade away. Thus I decided to support it.

What is it that fascinates you about this project?It combines two “passions” of mine: science

and music. I find it extraordinarily excitingto track down the secrets of why violinmakers such as Stradivari und Guarneriwere capable of producing such ex-traordinary instruments. Certainly,their craftsmanship was crucial, butapparently the wood they used alsoplayed a major role. For me, it’stremendously interesting to beable to scientifically explorethese materials-related as-pects of violin making.The results could shedlight on the origin ofthe exceptional tonalqualities of someantique instru-ments.

What are the goals you pursue with your Foundation?We support budding talent – not just musicians but

also scientists who don’t have the necessary financialmeans. Here, for example, we’re dealing with highlytalented young students who are allowed to participatein the master classes of famous artists such as CeciliaBartoli as part of the Menuhin Festival in Gstaad. OurFoundation also supports young talent from the scien-tific community who are pursuing especially innova-tive ideas. In evaluating them, we work closely withother institutions, which can prescreen possible candi-dates for us.

On a personal level, what are your hopes for theviolin project?

My goal is to help talented young violinists find aninstrument, which they not only can afford but, interms of tonal qualities, is at the same level as a violinmade by one of the great masters. I’m even ready toparticipate in privately financing the project further incase a company would eventually want to commer-cialise this biotech process; the Foundation itself doesnot pursue any commercial interests and operates as anon-profit organisation. //

Walter Fischli

The biochemist Walter Fischli is co-founder of Actelion, a Swiss biopharma-ceutical company with subsidiaries inmore than 25 countries. The companyfocuses on the discovery, develop-ment and marketing of innovativedrugs for unmet medical needs. For anumber of years, Fischli has concen-trated on fostering scientific relation-ships between Actelion and researchinstitutes. With his Foundation, hepromotes young talent in both musicand science.

Science and violin making –combined in an ideal way A patron explains his project


Acar consisting of a sin-gle molecule. That’ssomething Empa re-

searchers have developedtogether with their col-leagues at the University ofGroningen in the Nether-lands. With the help of aprinciple copied from na-ture, it travels in a virtually

straight line over a copper surface. In cells,what are known as motor proteins glidealongside other proteins, similar to a train onrails, and in the process “burn” ATP (adeno-sine triphosphate). The nano car – about onebillion times smaller than a VW Golf – is asynthetic molecule made of four motor units,which needs neither petrol nor rails to moveforward; its “wheels” run on electricity.

Refuelling is done via the tip of a scan-ning tunnelling microscope (STM), requiringa voltage of at least 500 millivolts. The elec-trons tunnel through the molecule and trig-ger structural changes in the motor units,turning each wheel one-half revolution. Ifthe wheels turn simultaneously, the auto(theoretically) moves forward along astraight line. The difficulty here is to stimu-late all four motor units simultaneously.

After ten STM stimulations, the car travels agood six nanometres, but the car must be re-fuelled every time the wheels rotate half arevolution.

A further experiment shows that themolecule actually functions as predicted.The central axis consists of a C-C singlebond, around which the front and rear halfof the car can rotate freely. It is thus possiblethat the molecule could “land” on the coppersurface the wrong way round with the rearwheels turning forwards and the front onesturning backwards – so the car remains ingridlock. If it lands in the correct orientation,all wheels rotate in the same direction andthe car starts to move. Because all four motorunits can be stimulated simultaneously, thecar has its own version of a “4-wheel drive”.There’s no reverse gear, though, because thewheels rotate in just one direction.

With this nano car, the researchershave demonstrated in a proof-of-conceptthat individual molecules can absorb exter-nal electrical energy and directly convert itinto targeted motion. In doing so, theyhave made a decisive step towards the de-velopment of molecular transport devices,which in future should allow them to per-form specific tasks on the nano-scale. //

The world’s smallestelectric carEmpa researchers have developed an emission-free, noiseless4-wheel car with electric propulsion. However, you’d havequite a difficult time taking a seat in it – the car is just4 x 2 nanometres in size and thus represents a decisive stepin the future of molecular transport systems.

TEXT: Michael Hagmann / PICTURE: Empa

08 // Research and development

1Gabor Kovacs puts one of hisartificial muscles to work: thisstack, which can lift a bunchof bananas, contains 2500individual polymer layers.

2This prototype of a pneumaticvalve is controlled by artificialmuscles and has proven itsvalue during several years ofindustrial usage.

Muscles madeof plastic

1 2


job in an industrial prototype. Applications in the consumer elec-tronics industry are also being looked into. For instance, artificialmuscles could allow the creation of a force-feedback touch screenwhich verifies the user’s key entry; for this, a pressed button yieldsand afterward springs back to the surface.

There’s no shortage of ideasBefore any such success, though, there’s still lots of work ahead.While there are hundreds of ideas for the uses of artificial muscles,only a few ambitious companies have dared to start mass produc-tion. This is where Empa is playing a role. Even now, Kovacs cansuggest three possible manufacturing methods which are to be fur-ther developed at Empa.

– For large-volume production and low-cost applications, theteam plans to develop a stacking machine to layer individualmuscle layers on top of each other. This machine fabricates arti-ficial muscles cost-effectively using prefabricated foil.

– Then, for muscles in an especially complex, delicate structure,high-precision manufacturing is needed. Such componentswould be plotted from fluid raw materials. A precise 3D pos-itioning robot is already operating in the Empa labs, and it canproduce components with micrometre accuracy.

– Actuators with high efficiency even at low voltage, are to be manu-factured using magnetron sputtering. For that, the entire produc-tion process takes place in a vacuum. A rotatable drum absorbsliquid silicon, which is then cross-linked under UV light. The nextstep in the process sputters a nanometre thin layer of silver,which acts as an electrode. The following step adds the next sil-icon layer, then again another silver layer, and so on.

The most advanced of these techniques is the plotter method usingfluid raw materials. Empa’s Functional Polymers Laboratory washeavily involved in the development of the electrode materials. Andthere’s even been a spin-off company, which resulted from this inter-disciplinary collaboration. The start-up Compliant Transducer Sys-tems (CT Systems), headed by Kovacs, was founded in August 2011and intends before long to mass-produce plotted artificial muscles.Another spin-off – Optotune – is already one step ahead; it is buildinglenses that can be focused continuously with the help of artificialmuscles (see article on p. 24). These lenses are superior to conven-tional systems in terms of size, manufacturing costs, energy con-sumption and robustness and thus are of great interest to companiesproducing smartphones. In other words, before long Empa re-searcher Kovacs will no longer have to deal with mere arm-wrestlingcompetitions. //

Artificial muscles are superior to electrical motors in many areas –such as in robotics or motorised prostheses. It could, however, bequite some time until we see replacements arrive in large volumes;so far, these devices are mostly hand-produced prototypes. Emparesearcher Gabor Kovacs, though, is looking into mass production.

TEXT: Rainer Klose / PICTURES: EmpaTEXT: Rainer Klose

With this system, we would have certainly won that armwrestling competition”, exclaims Gabor Kovacs fromEmpa’s Mechanical Systems Engineering Laboratory

with a wry smile. It is not with fond memories that he looks backupon that “man-vs.-machine” contest. In 2005, three internationalteams faced off to show in a spectacular way what artificial musclescan accomplish. Each team had developed a robotic arm, but backthen research on artificial muscles was still in its infancy. The resultwas sobering; all three robotic arms lost to their human opponent,a 17 year-old female student.

Since then a lot has happened. Artificial muscles, more properlyknown as electroactive polymers (EAPs), have become stronger andmore reliable. Lecturing at ETH Zurich, Kovacs is introducing thenext generation of engineers to this topic. The principle of operationis easy to understand: a thin sheet of polymer, 10 to 100 micrometresthick, is placed between two capacitive plates made of flexible con-ductive material. The polymer must be elastic, non-compressibleand a good insulator. When an electrical voltage is applied to the ca-pacitors, they attract each other and squeeze the elastic polymer flat.An artificial muscle is generally built up as a stack with dozens oreven several thousands of these individual muscle layers. It behavesjust like its natural archetype: when a voltage is applied to it, themuscle contracts and at the same time becomes thicker.

Artificial muscles remain intact even after hundreds of operatingcycles, their design is simpler than that of an electric motor, and theydon’t require any transformational mechanism to convert the rota-tions of an electric motor into a pulling or pushing motion. No won-der, then, that prototypes are already being investigated in everydaysituations. Several years ago Kovacs and his team built a pneumaticvalve from artificial muscles, one that even today continues to do its

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http://www.youtube.com/watch?v=Ga_IafGRWyEFor smartphone users: scan the QR code(e.g. with the “scanlife” app)

Video:Long StackedEAP Actuator⠀

Experiments with buildings?NEST makes it possible!Buildings are here to stay for a long time, a fact that hinders experimentationon them. With its “NEST” building lab, Empa is looking for a way out of thisdilemma. In NEST, only the supporting structure is permanent – all the rooms,including their facades, are interchangeable.

TEXT: Rainer Klose / GRAPHICS: Gramazio & Kohler; Empa

What do we actually need windows for?” asks Peter Rich-ner. This is not a purely rhetorical question because inRichner’s view the price we pay for a lovely vista is a

huge thermal weak point in the facade: energy escapes throughwindows. Richner, who as member of Empa’s Board of Directorsis responsible for the Civil and Mechanical Engineering Depart-ment, digs deeper into this issue. “Why not simply forget aboutwindows? We could build houses with webcams outside and flat-screen displays inside.” Such a building could be perfectly insu-lated. Richner looks out of his office window (which is still therefor now), scrutinising the dense fog and adding another interest-ing option. “Imagine you don’t like today’s weather. You simplypush a button on the display and in an instant the sky turns blue.Wouldn’t that be much more pleasant?”

In some ways Richner is right, but then again, maybe not. Whowould like to live in such a building? Which investors would dareto construct such a building and then tear it down after the inhab-itants moved out, shaking their heads? In today’s construction busi-ness, this daring idea would never stand the slightest chance.

Darwinism in building constructionEven so, we could soon learn what life in such a “flat screenpanorama loft” would actually be like. The “NEST” building labis intended to make this possible. A reinforced concrete core witha central stairway forms the backbone of the experimental house.Rooms, flats or even entire floors are attached to the outside. Thenall sorts of visionary and pragmatic ideas will encounter contem-porary and traditional living concepts in real life. A windowless“flat-screen loft” could be located immediately adjacent to a com-pletely ecological passive house module, walls perhaps made ofhemp fibre and brick clay, illuminated by wax candles. Next to itthere might be a high-tech module with the latest heating and ven-tilation electronics, all controlled with an iPhone.

The modular research house should, however, not only en-courage wild ideas but also lead to useable future concepts, muchfaster than would be possible in any other setting. What workswell catches on, and what is flawed will be replaced by anothermodule after two years. It’s indeed the survival of the fittest inbuilding construction.

What will life be like in tomorrow’s flats?Certainly, a selection of purely showcase modules would have lit-tle scientific significance. That’s why people are intended to actu-ally move into NEST and report on their experiences. Plans callfor a mixed usage with large open offices, conference rooms andflats. “We can imagine almost everything”, says Richner, “fromsingle-room flats for graduate students to 3-room split-level flats for

Focus: Smart buildings // 11

>>

NEST will be erected in theheart of the Empa campusin Dübendorf, whichmeans researchers, guestsand curious visitors won’thave to go far.

12 // Focus: Smart buildings

guest professors who come to do research for a semester and bringtheir families.” NEST inhabitants will thus have the chance to ex-perience how houses of the future affect people.

NEST is to be built on the Empa campus, that is, within eyeshotof its research staff, and a few of their projects are presented on thefollowing pages. Research in construction has been a main area ofactivity ever since Empa was established. However, until now therewere few possibilities to implement visionary concepts in a type ofopen-air laboratory. “In real life, a building must work from the verybeginning”, explains Richner. “There’s virtually no place for trialand error.” Back in 2005, during the construction of the ForumChriesbach on the Empa-Eawag campus, Empa’s experts on buildingtechnologies and construction would have been delighted to be ableto experiment with various types of facades. That, though, wouldnot have been compatible with its use as Eawag’s administrativebuilding. “Today that building is a state-of-the-art structure. It’s ex-cellent, but static”, says Richner. Each construction experiment endsas soon as construction is completed.

To be able to continue with experiments, Empa created theautonomous “Self” container, in which energy self-sufficiency andinsulation have reached levels unknown thus far. But even “Self”was finished eventually. The institute even decided to drop out ofthe Monte Rosa Alpine hut project. “It’s not hard to tell that amountain hut is a poor place for running experiments,” explainsRichner. “If something goes wrong, you need a helicopter in orderto make any repairs.”

Mistakes are OKNEST, located in the middle of Empa’s premises, is intended tosolve this problem. Here it’s OK to make mistakes. Here it’s OKto take a chance because the inserted modules are exchanged aftertwo or three years, paving the way for experiments in constructiontechniques with calculable risks. The supply backbone of re-inforced concrete, on the other hand, is a long-term investment inconstruction research; it will remain in use for decades.

Department head Richner wants to solicit proposals for vari-ous project phases. Topics such as “building automation vs. pas-sive climate control” would be possible; a number of options forrenovating older buildings could be investigated. Because eachmodule is connected to the core structure with a type of umbilicalcord, it’s possible to record and compare the flow of thermal en-

ergy, the need for chilled air in summer, electricity and water con-sumption. Richner is convinced that international research pro-jects will also show interest. “There’s nothing like NEST any-where else, it will be unique in the world.”

The truly most ambitious construction researchproject in SwitzerlandIn the end, NEST also serves as a research laboratory for Eawag,the Swiss Federal Institute of Aquatic Science and Technology.Water supplies and waste water methods will be investigated,while new options for recycling so-called grey and black watercan be tested in an actual setting and under defined conditions.

Still, this truly most ambitions construction research projectin Switzerland exists only on paper. At the moment, detailed plan-ning is being done to prepare for the construction bidding for thebackbone, which will start at the end of 2012 if everything goesas planned. At the same time, the search is on for industrial part-ners in Switzerland and abroad who would like to take part in thefirst round of experiments. Even after this first test phase, NESTwill be constantly changing shape and will investigate the“hot”questions pertaining to our living and working environment.This knowledge will then be passed on to the building and con-struction industry in seminars and conference series. //

>>

1NEST’s floor plan: each plat-form offers more than 600 m2

of space for experiments. Thestaircase, lift and utility shaftsare located in the core of thebuilding.

2NEST in various stages of com-pletion: the research modulescan be independently attachedor removed.

3Enjoying the pleasures ofsummer in the NEST cafeteria.

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Whether our society can achieve the agreed sustainability goalsdepends above all on how we build – and which materials weuse for that purpose. That’s because construction, operationand maintenance of Swiss buildings consume by far the mostresources. Specifically, around half of our energy needs comefrom buildings, and each year in Switzerland some ten tonnesof construction materials are used per person. At the same time,buildings are greatly responsible for our quality of life. Besides,architecturally successful and functionally pleasing buildingsendow a sense of identity and cre-ate long-term value. The bottomline is this: there’s no sustainablesociety without a sustainable builtenvironment.

Even if the quality of Swissbuildings at first glance seems quiteimpressive, we cannot close oureyes to a series of challenges. Inview of recent policy decisions re-lated to energy and the necessity tomassively cut CO2 emissions, present-day energy consumptionin Swiss buildings – which are fuelled primarily by fossil-basedenergy carriers – will sooner or later prove to be no longer ac-captable. In addition, a large number of buildings must not onlybe made energy-efficient, many of them must be completelyrenovated so they meet future requirements in terms of com-fortable and attractive living and working space. Around 1.5 mil-lion buildings will have to be replaced (or extensively renovated),which will likely keep us busy for decades.

There is also the need to upgrade our transport and supplyinfrastructure. For instance, roughly 40 per cent of the bridgesin the Swiss motorway network are older than 40 years. But itdoesn’t stop there: based on a growing population, this infra-structure must be continually expanded or at least adapted tomeet our increasing need for mobility. The associated costs willplace an enormous financial burden on the public sector in thecoming years and decades.

Empa’s Research Focus Area “Sustainable Built Environ-ment” is targeted at making a contribution towards overcomingthese challenges. In the development of new construction ma-terials, the primary focus is on reducing the consumption of re-sources – either through new materials with a lower fraction of

grey energy, new high-performance materials with improvedproperties or the recycling of construction materials. Exampleshere include innovative cements with a significantly lower CO2balance and a recently developed aerogel insulating plaster. Inboth cases, basic research was conducted at Empa, while at thesame time we are in close contact with industrial partners whocan bring these innovative approaches to market as fast as pos-sible. For example, in the next few months the first buildingswill be insulated with the new plastering system.

We must rise to the challenge ofdoing comprehensive renovations ofexisting building complexes from thestandpoint of technology, financesand urban design. To achieve this, wecannot limit ourselves to dealing withindividual buildings; it is perhapsmore important to address neighbour-hoods, districts or even entire cities.This includes questions relating towell-being and health: how must

buildings be arranged so there is no excessive heat build-up es-pecially in urban environments (the “heat island“ effect),which subsequently brings a large cooling load? How can weensure that air pollutants do not accumulate in our cities?

Sustainable construction which conserves our resourcesmeans we must erect buildings for the long term and make suretheir portion of grey energy and grey CO2 is kept to a minimum.In this regard, lightweight construction has great potential, butthere are still a few things we must optimise in terms of firesafety, acoustics and thermal masses – and these are all areaswhere Empa is actively conducting research.

However, (construction) research will eventually only besuccessful if it leads to practical applications, and so pilot pro-jects are very important. A new material or system might prom-ise to fulfill our expectations, but often this is proven only whenit is first used in an actual building where interactions with othercomponents and users come into play. The Forum Chriesbachat the Empa-Eawag campus, the “Self“ container for living andworking, which is self-sufficient in terms of energy, and thebrand new “NEST“ project are all examples of how Empa is pro-moting technology transfer and at the same time gathering newstimulus for its research. //

We need moresustainable construction

“Present-day energyconsumption in Swissbuildings is no longeracceptable.”

TEXT: Peter Richner, member of the Empa Board


Split-level flats forvisiting scientists: lightweightMinergie construction withstate-of-the-art materials

and systems, new shapes andsmart technology.

What’s going onin this NEST?The planned building lab on the Empacampus should serve, quite literally, as aplatform for new ideas in constructionand sustainable, energy-efficient solutions.Research modules for future residentialand office rooms are installed on eachopen floor. Building services are suppliedcentrally from the inner core.

V I S I O N

01

Graduate-student flats:

contemporary, modular rooms,

digital networking, smart

technologies, functional

materials and surfaces.

V I S I O N

03


Plus-energy common room:

intelligent glass architecture,

adaptive photovoltaic

protection from the sun,

innovative lighting systems.

V I S I O N

02

Residential module for

visiting scientists: passive

room module made of

state-of-the-art natural

materials, the comfort of

nature, minimal technology

V I S I O N

05Creative workplace:

efficient, networked workingspace, energy-conserving

communication technologies,intelligent lighting.

V I S I O N

04


Retaining the summer suninside concreteConcrete is the most popular construction material in the world, with 20 to 30 billiontonnes being used each year. A project at Empa now demonstrates that concrete is notonly solid and durable, but can do far more: serve as a seasonal heat store.

TEXT: Nicole Döbeli / PICTURE: iStockphoto

Ahot stone cools off slowly, especiallyif it is wrapped up in insulation ma-terial. Even so, it continually loses

heat. Because it’s not so simple to wrap upentire buildings that get heated up duringsummer, Empa researchers Josef Kaufmannand Frank Winnefeld sought another solu-tion for a seasonal heat storage method.

Conventional concrete consists of up to15 per cent of the mineral ettringite. When itwarms up to above 50°C, ettringite begins toevaporate water. If water is later added to thedehydrated material, the hydration reactionreleases heat. In order to store as much ther-mal energy as possible, the concrete mustthus contain the maximum amount of ettrin-gite. That, however, is possible only with spe-cial cements, one being calcium sulphoalumi-nate cement (CSA), which has long been usedfor concrete production in China and can con-tain as much as 80 per cent ettringite. Thereis another advantage compared to conven-tional cement: during its production, CSA ce-ment releases 40 per cent less CO2.

The Empa alternative:chemical thermal storageStoring surplus summer heat for the winter months is also possible with what is knownas sorption storage, for example with NaOH, in other words caustic soda. In a sorptionstorage system developed by Empa researcher Robert Weber, water is driven out of theNaOH sorbent during summer months using heat from solar collectors. The water vapouris condensed and stored separately from the dehydrated sorbent. In winter, the stored wateris added back to the sorbent releasing thermal energy, which can be used to heat a homeor produce domestic hot water. The advantage compared to conventional thermal storagesystems is that there are no thermal losses during the storage period. In addition, the vol-ume is roughly five times smaller than with a comparable water storage system; for a pas-sively heated single-family house, a 7m3 storage tank is adequate to generate heat and do-mestic hot water from solar energy throughout the entire year.

Kaufmann and Winnefeld manufac-tured concrete slabs made of CSA cementand piled them up to blocks in which heatingcoils had been embedded. In the summer, ifthe blocks are warmed to 80°C for instancewith the help of solar collectors, the ettrin-gite begins to release water. The vapour iscollected and condensed. What remains isdehydrated concrete, which can be storedwithout any loss of thermal energy.

In winter, the process runs in reverse:water or water vapor is added to the con-crete, taken up by the ettringite – whichthen releases thermal energy that can be“harvested” through the heating coils. Theadvantage compared to other thermal stor-age methods is that the release of heat canbe regulated by the amount of water addedto the concrete. In this way, for example,under-floor heating can be maintained allwinter long at 25°C, or domestic hot watercan be kept at 40 °C.

The concrete storage scheme also offersanother advantage; the difference in volumebetween dehydrated and hydrated concreteis insignificantly small as opposed to a paraf-fin wax storage system, which expandswhen the paraffin melts. To heat a single-family home (Swiss Minergie-Standard) overthe winter months, a cube of concrete witha volume of 15 cubic-meters (fed by a collec-tor area of 15 square-meters) would suffice,because the heat-storage-capacity is largercompared to a water or paraffin thermal stor-age unit. From a cost point of view, concreteis also competitive; a tonne of CSA-basedconcrete costs less than 400 Swiss francs,whereas a ton of paraffin is about 1000 Swissfrancs. And with one to one and a half charg-ing cycles per year, the “concrete heating”should last for at least 30 years.

Kaufmann and Winnefeld have alreadypatented the process. They now intend to fur-ther develop and test the concrete heat storein collaboration with industrial partners. //

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Computer modelling of phases and volume

anhydrite


With the help of a database and thermodynamics software, theproperties of concrete can be calculated in advance and optimisedaccordingly. The benefits are substantial: CO2 emissions can bereduced and building components kept up much longer.

TEXT: Nicole Döbeli / ILLUSTRATION: Empa

From six to eight per cent of the global CO2 emis-sions are caused by the manufacture of cement,even though far less CO2 is released per tonne of

cement compared to steel or aluminium – specifically,just less than a tonne. The problem lies in the quantity.Globally, some three billion tonnes of cement are pro-duced each year and rising.

One way to alleviate this situation is to use raw ma-terials with a lower carbon content so that CO2 emis-sions during cement production sink. If structures builtthis way kept up for much longer, that would be an ad-ditional step towards CO2 reduction.

Barbara Lothenbach devotes her time to improvingcement mixtures. Because there are (at least theoret-ically) any number of recipes for cement, she hashelped develop a computer program to predict thechemical reactions during the setting of cement. GEMS(the Gibbs Energy Minimisation Selector), as the pro-gram is called, originated at the Paul Scherrer Institute(PSI) where it will be developed further. GEMS per-

forms thermodynamic modelling of materials, and itcalculates how materials behave and change under cer-tain circumstances and over time. Lothenbach has “fed”GEMS with the values from Empa’s cement database.This allows her to model a virtual manufacturingprocess using all cement minerals and additives regis-tered in the database to create every possible mixtureand then calculate their properties and behaviours –even over a span of years.

One research project, for instance, is addressing thelong-term stability of concrete in the construction oftunnels. If mountain water containing sodium sulphatepenetrates into a tunnel, it reacts with the concrete tomake ettringite and thaumasite, two minerals that re-duce concrete’s structural strength and thus make itmore prone to flake or chip off. With the help of GEMS,Lothenbach can simulate this reaction. That make itpossible, when planning a construction project, to se-lect a suitable cement mixture to prevent the build-upof ettringite and thaumasite. For example, fly ash canbe mixed into the cement to make it more resistant towater containing sulphates. With this computer simu-lation, Empa is a worldwide leader in the thermo-dynamic modelling of cement. //

And now the forecast …

Both composition and volumeof a concrete sample changesduring the setting process.Computer modelling helps withthe precise prediction of theproperties for a given mixtureof materials. Empa is aworldwide leader in this area.


1High tech and older buildings: this electronichumidity sensor is situated behind theexterior surface of the reconstructed wall similarto what you might find in an older building.Dozens of sensors are installed in the test walls,and their readings indicate how well theinsulation is working.

2Insulation tests being conducted on three testwalls: each exterior wall is exposed to severeclimactic conditions (sun, rain, sub-zerotemperatures) in a climate chamber, while the«interior wall» is accessible from the laboratory.

3Project leader Thomas Stahl explains theconstruction of the wall section. Thenew insulation should not result in the beamgetting mouldy, otherwise the building’sstructural stability is at risk.

Using state-of-the art electronics, Empa researchers are investigatingreplicas of walls from older buildings in the lab to test and improveinnovative interior insulating materials and renovation techniques.Not only homeowners will benefit from optimally insulated buildings– but Switzerland’s carbon footprint, too.

TEXT: Rainer Klose / ILLUSTRATION: André Niederer / PICTURES: Empa

Energy policy starts in the living room,because comfortably warm Swisshomes make the country dependent on

imported oil and gas. The Swiss Federal Officeof Energy (SFOE) measures this dependencyeach year and it’s increasing. In 2010, energyconsumption reached a new record: 911,550terajoules (253 billion kilowatt-hours), whichis 4.4 per cent more than in 2009 and a solid30 per cent increase compared to 1980.

Are we at least ecological when it comesto our energy consumption? Not really. Lastyear, we imported among other things 4.5million tonnes of light heating oil and 3.1 mil-lion cubic metres of natural gas. Taken to-gether, these non-renewable energy carrierscovered approximately a third of Switzer-land’s energy needs. In contrast, renewableenergy didn’t come anywhere close – 0.2 percent each from biogas and solar power, and1.2 per cent from environmental sources ofthermal energy (geothermal, water, air).

The conclusion is simple: we continueto heat our homes, offices and public build-ings primarily with imported fossil fuels.According to SFOE statistics, room heating“eats up” more energy than all domestictransportation in Switzerland, it consumestwice as much as all industrial processes,ten times more than all lighting and 30times more than communications, Internetand consumer electronics. Reducing CO2emissions, therefore, is mainly about onething: insulating buildings. Not only newconstruction must fulfil increasingly higherstandards, but especially older buildings –in Switzerland roughly 1.4 million of them– must be renovated to conserve energy.

The challenge here is that the FederalCommission for the Protection of Nature andCultural Heritage wants to preserve the visualappearance of historical buildings and seldom

allows insulation on the exterior. And so theonly choice is insulating from inside, a solu-tion with a number of strings attached to it.Insulation done too well can threaten an olderbuilding, even ruining it to the point where itis uninhabitable, says building physicist andengineer Thomas Stahl. “If old brick walls areinsulated from inside, the wall can freezethrough on the outside. That brings the dan-ger of frost spalling, which impairs load cap-acity.” Things can get even worse if load-bearing wooden beams are insulated improp-erly. “Condensate develops on a beam’s rawedge, and it can rot through within just a fewyears. Then you might as well tear the housedown,” the Empa researcher says.

To avoid this, Stahl is systematically in-vestigating the interaction of old buildingswith modern methods of insulation. But howdo you simulate an older building? Quitesimply – with bricks, roughcast and wood,in other words, the building materials of

A good insulationpays off

experimentalinsulation

external plaster

interior plaster

sensors for temperature and moisture

sensors formoistures

perforatedbricks

sprucebeam

those times. Also needed is a powerful en-vironmental chamber in which these mate-rials can be “tortured”.

The set-upLocated in the construction hall at Empa thereare three identical wall sections which repre-sent typical home construction from the1950s. They have support structures made ofred perforated brick, an outer skin of lime-stone cement plaster, and an inner layer ofwhite lime plaster with no insulation. In ad-dition, a spruce beam is sticking into eachwall; inside, it rests on a piece of the wall andis protected from outdoor weather conditionsonly by a thin brick wall. “With this sectionof the wall we can test how our insulationinteracts with a typical ceiling beam of an old-er house”, explains Stahl. The spruce beam ismore than 100 years old and was purchasedfrom a dealer specialising in historical con-struction materials.

1


The experimentThe wall sections are then placed withinEmpa’s climate chamber and subjected totests designed by EOTA (European Organ-isation for Technical Approvals). The ex-terior wall is exposed to rain and sun for 25days, cooled to temperatures below freez-ing and warmed up once again. The insideof the wall section remains at laboratoryconditions: 40 per cent humidity, 22 °C.“This test is quite dramatic”, says Stahl,“and it simulates the actual stresses thatarise over more than a year.”

After data for the unaltered wall is col-lected, the walls are insulated and once againsubjected to the EOTA test. Here, special at-tention is paid to see if something goes wrong.Does water collect in the wall? Does the beamget damp? In case of doubt, the test is repeat-ed with the beam left unprotected withoutany insulation. According to Stahl, “We wantto document how to avoid mistakes.”

In order to determine if a wall beingtested is getting cold or wet, Empa re-searchers embed specially developed mois-ture sensors within the plaster. The sprucebeam is also studded with sensors. The oldconstruction wall in the Empa laboratory isin fact a completely wired high-tech cli-mate spy, and a perfect foundation for per-forming insulation experiments. “We wantto know exactly what is happening insidethe wall, why it happens and how badthings get when it happens,” explainsStahl.

The experiments at Empa are not beingconducted in isolation but rather as part ofa larger research project called Sahib (Sus-tainable Renovation of Historical Build-ings). Three industrial partners are in-volved in the first round of experiments.They supply a variety of insulating systems(see box) and want to run a comparisontest under identical conditions.

The findingsThe goal of this head-to-head comparison,though, is not to name a winner or a loser.Of course, not every material has equally ef-fective insulating properties. The test willshow what new types of insulation have tooffer – as well as their limits. Afterwards, thematerials will be entered into an internation-al database for construction materials,which will be accessible to architects and de-signers around the world. Properties to belisted will include, among other things, thesorption isotherm (a value for moisture re-tention), thermal conductivity, thermal cap-pacity, porosity and density as well as thewater vapour diffusion resistance factor µ(see box). In addition to raw numeric values,the tests also supply knowledge about theinteraction of the insulation with the entirewall system. In this way, manufacturers canaccess detailed knowledge about the materialproperties of their products. Their customersthen purchase construction materials, whichhave been extensively tested-instead of buy-ing a pig in a poke.

Theory and practiceThe experiments will also pay off forThomas Stahl. The future of building tech-nologies lies in computer simulation, fedwith data about various materials. Datafrom the 25-day EOTA test can be extrapo-lated to many years on a computer. Be-cause the test walls can be reused andequipped with new layers of insulation,Empa’s investigations over the next severalmonths will supply large amounts of newdata, which can be used to refine currentcomputer models. Both homeowners andtenants will profit from this knowledge,and in the long run, also the Swiss carbonfootprint. //

Empa testing of interior insulation

EPS (extruded polystyrene) with capillary active additive, thermal conductivity approx. 0.035W/(m K), water vapour diffusion resistance factor* approx. 30, weight by volume 20 – 40 kg/m³Aero gel insulation sheet, thermal conductivity 0.0131 W/(m K), water vapour diffusionresistance factor* 11, weight by volume 150 kg/m³Vacuum-insulated panel, thermal conductivity 0.007 W/(m K), water vapour diffusionresistance factor*: impervious to water vapour, weight by volume 180 – 220 kg/m³

* The water vapour diffusion resistance factor µ indicates the permeability of a material to watervapour compared to a stationary layer of air. A higher value of factor µ means the material ismore impervious to water vapour. Because of issues dealing with interior climate, many buildingowners prefer water vapour- permeable construction materials. Experts, though, disagree as towhat conclusions to draw from this parameter.

2 3

26 // Im Dialog20 // Focus: Smart buildings

Smart glass, which becomes dark, translucent or UV-reflective at the push of a button,offers considerable advantages in building technologies. Manufacturing such glass,though, is complicated and expensive. Empa researcher Matthias Koebel is on a questto find cost-effective processes.

TEXT: Rainer Klose / PICTURES: Empa, iStockphoto

Someday soon, rolling down window blinds will be consid-ered hopelessly old-fashioned. When people get home in theevening, they will turn on the lights and, instead of drawing

their curtains closed, will simply “dial up” their living room win-dows using a smartphone app. In an instant, those windows willbecome translucent, and the evening will begin undisturbed byneighbours’ curious gazes.

To make such visions reality, we need what is referred to assmart glass. These are window panes with coatings, which changetheir optical properties when an electric voltage is applied: fromclear to translucent, from bright to dark, from transparent to re-flective. They will make window blinds superfluous, curtains willbe nothing more than decorative elements.

Matthias Koebel, an expert in the chemistry of colloids and sur-faces at Empa, is working to bring this type of futuristic window intoour lives. Smart glass already exists today, but manufacturing it withcomplex vacuum sputtering processes is expensive. Thus, thesedays we encounter smart glass only in small surfaces: automotiverear-view mirrors that dim themselves automatically, museumshowcases, which become translucent and serve as a projectionscreen, or cabin windows in the new Boeing 787 Dreamliner turningdark at the push of a button. It would be very desirable to make allof these properties available to large glass surfaces, but to do so weneed an inexpensive coating method which can easily be adaptaedto large industrial processes.

Colloids from an ink jet printerThis is where Koebel enters the scene. He is an ex-pert in colloidal solutions and thus very experi-enced in getting insoluble materials to “hover” inliquids or to turn them into extremely small par-ticles invisible to the eye. Koebel is convinced thatwith the help of colloids it should be possible to cre-ate inexpensive coatings on large surfaces.

The first experiments are already under way, and Koebel’slaboratory is equipped with a type of professional ink jet printer.“With it, we can apply thin layers of only 100 to 200 nanometreson glass. They dry within seconds and afterwards can support ad-ditional functional layers”, explains the researcher. “This lets ussystematically build up layered structures of high complexity.” Animportant aspect for this functionality is a uniform layer thick-ness. After they dry, finished samples are examined with a scan-ning electron microscope (SEM), atomic force microscope (AFM),optical spectroscopy and other conventional surface-specificmethods.

Within Empa, Koebel is coordinating the “Empa Window” pro-ject, leading a team which deals exclusively with smart materials forwindows. These activities, which began just several months ago, arealready bearing their first fruit in the form of two EU project pro-posals. In both cases, the research partner is the Fraunhofer Institutefor Solar Energy Systems (ISE) in Freiburg/Germany. The re-searchers at ISE have decades of experience with glass coatings, andin this project they are developing a “dry” sputtering process, inwhich the coatings are vapour-deposited in a vacuum. Empa, in con-trast, is investigating the possibilities and properties of layers appliedwith “wet chemicals”, specifically using colloidal solutions.

It could be quite some time, though, before the first elec-trically switchable panes of glass are available on the market.

Thus, whether they like it or not, today’s home ownerswill still have to install “old-fashioned” window

blinds, but their replacement is already beingworked out in Dübendorf. //

A window for any occasion

Matthias Koebel fills his “lab printer” with a colloidal solution.The functional layer is printed on a glass microscope slide,dried and then analysed in a scanning electron microscope.

Im Dialog // 27Knowledge and technology transfer // 21

“Steam blasting”with real goldEmpa researchers are writing fashion history with a vacuum coating system.Using high tech methods, they can produce a yarn with a layer of pure 24-caratgold. This spring, the material will have its premiere on the catwalk of anhaute couture collection; a line of neckties is already available.

TEXT: Rainer Klose / PICTURES: Empa; Vincent von Ballmoos

Project manager Martin Amberg is looking through apeephole inside his coating system, obviouslypleased, even though there’s really not much to see.

Violet light fills the interior of the apparatus roughly thesize of a home refrigerator. Threads are strung up side byside in the machine and move past the peephole.

The violet light emanates from a piece of gold whichis degraded into its atoms by high-energy radiation. The re-sult emanates from the other end of the apparatus. A thintube, almost like a straw, points upwards; from its top, a

>>

thread is pulled out and wound on a bobbin. The coiledthread shines with a golden hue in the sunshine comingthrough the window into this industrial building.

In an adjoining room at the Tersuisse spinning millin Emmenbrücke, with Empa’s assistance, a world’sfirst is taking shape: a fibre with a 24-carat gold coating.Fabrics woven from it sparkle with the characteristiccolour of this precious metal, but they don’t require cus-tomers to make any compromise. The fibres have a softfeel, are abrasion-proof and can even be safely put in a

22 // Knowledge and technology transfer

washing machine. This fibre has been in pro-duction since summer of 2011. The firstbatch went to the spinning mill atWeisbrod-Zürrer AG in the townof Hausen am Albis, where it isprocessed together withblack silk into material in-tended for ties. Startingwith a panel of fabricwhich contains 25 grams ofgold, it is possible to makethree ties, a bow tie and apocket handkerchief. It goeswithout saying that suchproducts are not an inexpensiveindulgence.

But how does the gold get on thefibres? Empa researchers decided to use aprocess called magnetron sputtering. For this, they re-quire only a bit of electricity, a medallion made of gold,a few litres of argon gas and a vacuum container largeenough to unwind 4,000 metres of thread in narrowloops. Anyone who has assembled all this can vaporisegold at room temperature and fabricate gold thread. In-side the coating system, the gold piece, called a target,is bombarded with fast-moving argon ions. Atoms ofgold are “knocked out” and deposit themselves on apolyester thread, which is pulled slowly through themachine just a few centimetres from the target.

Of course, things aren’t quite that simple, the devilis in the details: for instance, how the polyester threadhas to be prepared so that gold actually sticks to it,which operating voltage and layer thickness yield thebest effect – all trade secrets. When the first proud own-ers will put on their gold ties at Christmas of 2011, thismoment will mark the culmination of a 10-year researchproject. That’s how long textile experts at Empa in St.Gallen have been testing and refining the magnetronsputtering method. To gain systematic experience, theysputtered all sorts of metals – titanium, aluminium,steel, copper and silver – and let them rain onto variousfibres.

The project’s goal was initially a thread of silver,which immediately found a number of markets. Silver-coated fibres have an antibacterial effect, something ofinterest to, for example, clothing manufacturers whouse it to make odour-free socks. In addition, fashion de-signers were looking for durable silver-coated textiles.Furthermore, silver conducts electricity extremely well,making the Empa-developed fibre extremely well suitedfor use in various sensors and as an antistatic filter ma-terial for industrial applications. “What is possible withsilver might also work with gold”, the project partnersthought to themselves. So in January 2010 they startedworking on “Project Gold Fibre”.

There were, however, many problems to be solved.How much gold is necessary to make the threads shine?Does a base of silver improve the sheen? Can silver and goldbe applied in the same stage, thereby allowing an “alloy” tobe manufactured directly on the thread? The result of aseries of tests showed that an amount of 3 grams of puregold per kilometre of thread produces a lovely sheen in

>>

1

Knowledge and technology transfer // 23

a discrete antique shade of gold. Further, if the base ismade of silver, the gold shines considerably brighter;the colour is as striking as on a large piece of gold jew-ellery. The silver layer can be applied in the sameprocess stage if gold and silver targets are inserted nextto each other in the machine and are bombarded simul-taneously. Thus, a gold coating can be manufactured fora wide range of fashion accessories and various tastes.While a businessman might want a tie in a discrete an-tique gold, it might be desirable to have the delicate em-broidery on a woman’s evening gown shine somewhatbrighter.

After 24 months, Project Gold Fibre is reaching asuccessful conclusion. The further processing of theyarn is being taken over by two partner companies whowere involved in the project from the very beginning:Weisbrod-Zürrer and the embroidery and decorativematerial factory Jakob Schlaepfer in St. Gallen. A limit-ed series of gold ties is already on sale for the Christmasseason. Because of the limited amount of available goldfibre, there will only be a dozen gold ties for affluentcustomers around the world. Exclusivity, a preciousmaterial and high-tech production methods have theirprice – a buyer must come up with 7,5000 Swiss francsfor a tie. For this price, though, he can be assured thathe is wearing roughly eight grams of pure gold.

In future, too, the gold ties won’t be going into massproduction. At full capacity, 600 pieces could be manu-factured annually. Certainly, though, it will be far few-er because a part of the fabric production is beingreserved for the second project partner, JakobSchlaepfer, who plans on using the goldenfabric for its winter 2012/13 haute couturecollection, which will be presented thisspring. //

1Project leader Martin Amberg monitors the vacuum-coating system, in which a simple polyester thread is“transformed” into a true gold thread. Bottom photo:a silver target that has already been used. Bombardmentwith argon ions etches a circular groove in the metal.

2On location at the Hofmann tie plant in Zurich:the gold fabric consisting of gold threads and black silkis cut by hand and sewn into an elegant tie. Bottomphoto: Martin Amberg and textile engineer ChokriBenkhaled Kasdallah are very pleased with the result oftheir efforts.

http://tv.empa.ch/empa_tv_goldkrawatte_20111201.m4v For smartphone users: scan the QR code(e.g. with the “scanlife” app)

Video:Gold-plated clothes

2

24 // Knowledge and technology transfer

Optical instruments for the aerospace market; a wirelessmonitoring system for mechanical structures; an intelli-gent bed for the bedridden; a process to analyse and sort

grain by the tonne; resilient components for machine construc-tion; optical lenses, the focus of which can be changed continu-ously – all these products and processes come from a single build-ing, Empa’s glaTec technology centre in Dübendorf. Or in otherwords, from the companies that operate there, including Empaspin-offs and other start-ups whose names have a high-tech ringto them such as Decentlab, compliant concept, QualySense,Monolitix, Optotune and Micos Engineering.

When the first start-up – Optotune – moved into glaTec, itsfounders already had something in their arsenal that many youngcompanies lack: a fully-fledged business plan with a pretty matureidea about their product. The company’s flexible optical lenses,which can be focused continuously with “artificial muscles”, areclearly superior to conventional systems in terms of size, manu-facturing costs, energy consumption and robustness. Even so,“It’s possible to put together a demo version in virtually no time,but the real test is whether you can also sell it to potential cus-tomers”, relates Mark Blum, co-founder and COO of Optotune.The products from this start-up can be used in a variety of appli-cations, for example in lighting fixtures for museums, shoppingcentres or homes, but also for fast-operating barcode scanners oras an optical zoom in a smartphone.

What the Optotune team was looking for and found in 2009at Empa’s business incubator was urgently needed space with thenecessary infrastructure as well as a research group in immediatevicinity working on a similar topic – electro-active polymers (EAP)or artificial muscles. With Empa researchers led by Gabor Kovacsand Silvain Michel, they were not only able to exchange technicalideas but also set up a suitable laboratory – an aspect of im-

This way, please !

What is glaTec?

The non-profit promotion agency glaTec operates a technology centreat Empa in Dübendorf to support the establishment and develop-ment of companies and innovative processes in the areas of materialsand environmental science and technology. glaTec is funded byEmpa, Eawag (the Swiss Federal Institute of Aquatic Science andTechnology), glow (the Glatt Valley Economic Promotion Agency), theEconomic Promotion Agency of the canton of Zurich as well as thecities of Dübendorf and Zurich. www.glaTec.ch

portance to Empa. “For us, it’s a central concern that start-ups area good fit with Empa so we can develop joint research projects”,notes glaTec’s Managing Director Mario Jenni.

Different challengesEach start-up faces completely different challenges. For Optotune,finding suitable premises as well as having contact with other re-searchers was most important, whereas other start-ups mightneed help with market studies or coaching for (often tedious) ne-gotiations with potential investors. “Especially in the early phaseof establishing a company, a path is chosen, which somehow pre-determines the chances for ultimate success”, points out Jenni.Therefore, it’s crucial for neo-entrepreneurs to seek out supportat a rather early stage. This means, for instance, bringing expertsinto the team to address business issues or to guide the new-com-ers during negotiations. Adds Jenni, “This is eventually the pathto independence.”

Since 2009, six start-up companies have settled into glaTec, Empa’s technologycentre in Dübendorf. The first of them, Optotune, recently left the businessincubator “on schedule” to ramp up production of its optical lensesat a new facility. But just as in any other desirable location, the space won’tbe empty for long. Start-ups already operating there are expanding, andnew ones are looking for proximity to Empa, which promises a lot of synergies.

TEXT Martina Peter / PICTURES: Empa

Knowledge and technology transfer // 25

Potential tenants at glaTec are spin-offs from institutionswithin the ETH Domain, external start-up companies, R&D unitsworking separately from their companies as well as public-privatepartnerships. Optotune is a spin-off of ETH Zurich; at this time,glaTec is home to three Empa spin-offs, one external start-up andan ABB spin-off (see table). “Our focus”, explains Jenni, “is clear-ly on early-phase projects working in the areas of materials sci-ence, environmental science and technology.” It goes without say-ing that not every company that would like to become part of thisEmpa technology centre can be accepted. The admission processis quite selective; projects are first painstakingly evaluated byglaTec’s Advisory Committee. Businessmen, CTI start-up expertsas well as those with experience in marketing, legal issues and fi-nancing examine the applications in great detail, sounding out theproposals with regards to innovation, market potential and feasi-bility. Only then does Empa’s Board of Directors take a decisionas to whether a company will be accepted into their incubator.

Advice, support, contacts It sometimes happens that members of the Advisory Committee alsotake on the role of coach who can address the start-up’s key issues,just in case Jenni, an experienced businessman himself, can’t pro-vide further assistance. For such situations, he has ready access toa large number of contacts from his professional network or can pro-vide tips as to how and where to find the right expert for a specificproblem. Jenni also works closely with other entrepreneurial pro-motion agencies such as the Swiss Innovation Promotion AgencyCTI, tebo (Empa’s technology centre in St. Gallen) and ifj Institutfür Jungunternehmen (Institute for Entrepreneurship).

Start-ups which set up operation in the business incubator canstay as long as three years. During this time, they profit from ad-vantageous rental rates and Empa’s first-class infrastructure. Af-

Success at glaTec

One hundred experts recently selected Optotune asthe best start-up of the year under the auspices of ifjInstitut für Jungunternehmen (Institute for Entrepre-neurship) in St. Gallen. The ranking lists a total of 100companies from all over Switzerland. In addition, thetwo glaTec companies QualySense (#26) und compli-ant concept (#73) also made it into the Top 100.

terwards, the companies should have sufficient equity or debt cap-ital to set up operations elsewhere – and free space for other bud-ding companies.

Optotune was successful in doing just that. As planned, thispast summer the company moved to Dietikon in the Limmat Val-ley, where it is ramping up production of its lenses so as to be pre-pared for the new-product introductions of its various customers.Concerning the initial assistance they received at glaTec, the suc-cessful entrepreneurs are extremely grateful. “We’ll never forgetthe friendly, cooperative people we had the pleasure of getting toknow at Empa”, they wrote to Jenni.

Now that Optotune has moved out of the Empa complex, thereare currently five companies residing in the technology centre,three of them Empa spin-offs.

– compliant concept GmbH is developing an intelligent bedsystem with the goal of preventing the bedridden fromdeveloping bedsores.

– Decentlab GmbH supplies a wireless monitoring system for theflexible supervision of structures and construction sites.

– Monolitix AG develops and markets components and systemsfor machine construction, in particular solid joints as well ascompliant mechanisms and systems.

– The external start-up QualySense AG offers a process, whichsorts grain deliveries by the tonne, doing so with high precisionaccording to biochemical parameters.

– The ABB spin-off Micos Engineering GmbH specialises in opticalinstrumentation for the European space market. //

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Video:Plastic muscles formobile phone cams

Laboratory-testing of a compliant concept mattress.

26 // Science dialogue

New member of the Empa Board

At its December meeting the ETH Council, thestrategic management and supervisory body of theETH Domain, appointed a new member to Empa’sBoard of Directors: Brigitte Buchmann, a chemistand expert in air pollution emissions. She will as-sume leadership of the Mobility, Energy and En-vironment Department on 1 September 2012.

In her role as department head, Brigitte Buch-mann will succeed Peter Hofer, who is retiring inmid-2012. She studied chemistry at the Universi-ty of Zurich and in 1988 received her PhD inorganometallic chemistry. In 1989, Buchmannjoined Empa and managed the Emissions Groupin the Laboratory for Air Pollution/Environmen-tal Technology. She also took over as projectmanager of the National Air Pollution MonitoringNetwork (NABEL), which helps establish the sci-entific basis underlying Swiss air-pollution pol-icy. Based on her experience and success with theSwiss measurement network, she has since 1995headed up the World Calibration Centre forozone within the Global Atmosphere Watch Pro-gramme (GAW) of the WMO (World Meteoro-logical Organisation).

As Laboratory Head since April 2002, Buch-mann has consistently focused on developing newtechniques for measuring atmospheric trace sub-stances as well as on computer modelling of pol-lutant sources. She used satellite data to investi-gate Switzerland’s air quality and in this way “pro-pelled” pollution measurements into the third di-mension. As a member of the Swiss Commissionfor Space Affairs as well as serving as a Swiss dele-gate to the ESA, she was involved at a strategic level in the use of satellites for earth observations.

Taking a peek insideIt was during a company Christmas party exactly 20 years ago thatEmpa took delivery of its first computer tomograph. Today, Empais one of the leading institutes in the area of industrial computertomography and operates four systems. But it’s by no means justindustrial components ending up under the X-rays...

Consider, for example, cheese. What is the distribution of holesin Swiss cheese? This was one of the tasks assigned to Empa duringan applications contest. The most challenging ones were selected,and for each one a computer tomograph (CT) scan was made at nocharge. By looking at the cross section of a wheel of cheese it ispossible to see exactly how many holes it has, how large they areand where they are located.

Empa’s CT experts have also peeked inside a Toblerone choc-olate, trumpets, rhinoceros skulls and gold Celtic artefacts. These“exotic” cases, though, are the exception rather than the rule. Nineof ten contracts come from industry, which depends heavily on thenondestructive testing of components or 3D analyses. For example,what if the blueprints for old components are no longer availablebut new parts must be manufactured according to the old pattern?A computer tomograph of the original component reveals how itwas designed and built.

In contrast to a medical computer tomograph, those for indus-trial purposes must be much more precise. Correspondingly, in-dustrial tomographs take much longer to illuminate everything in-side. A medical CT scan can take some 90 seconds and revealeverything that is important to a physician. An industrialCT scan, though, can take several hours depend-ing on the system and material.

Empa works with one of thelargest computer tomo-graphs in Europe. With it, re-searchers can make images ofcomponents weighing asmuch as two tonnes such asparts of lorry engines. At theother end of the scale, things arewide open, too. The Empa tomo-graph has no problem at all spot-ting a 25 micrometer error on a sol-der joint just a few millimetres wide.

Alexander Flisch prepares a fossil for the CT analysis.

Science dialogue // 27

2011 Swiss Design Prize

Textile designer Annette Douglas has received the highly coveted 2011 SwissDesign Prize in the category “Textile Design Award A” for the CTI project“Sound-absorbing, translucent and lightweight textiles”. She was awardedthe prize together with the company Weisbrod-Zürrer and Empa scientistsReto Pieren and Kurt Eggenschwiler, who worked out the acoustic funda-mentals for the world’s first sound-absorbing and translucent curtain.

The two experts from Empa’s Acoustics/Noise Control Laboratory firstdeveloped a computer model, which not only describes the fabric’s micro-scopic structure but also its macroscopic composition. Then, with the helpof acoustic measurements on woven samples, they optimised the fabric.Next, Douglas succeeded in translating the new findings into weaving tech-niques. Finally, Weisbrod-Zürrer customised the manufacturing process sothat the curtains can now be produced on an industrial scale.

The jury praised these efforts, saying that the materials are a true, valu-able innovation, which should soon be established on the market. “They arecharacterised by a simple, unobtrusive appearance, which nonetheless re-tains elegance and class, and they will open entirely new opportunities forinterior design.”

Energy from sewage sludge

Producing energy from waste – that wasthe topic of Silvan Weder’s high schoolgraduation project. Inspired by an articlein “Spektrum der Wissenschaft” – the Ger-man edition of “Scientific American” –, hegot in touch with Empa. “The goal was toproduce energy exclusively from biogenicwaste products so that power generationdoes not compete with foodstuff produc-tion”, he explains. Working with Empa re-searcher Andreas Borgschulte, he createdan experimental set-up. In it, biowastesuch as plant debris is deposited in an air-tight container, which is placed in a waterbath with a constant temperature of 60°C.Beforehand, though, the biowaste is in-jected with sewage sludge containing spe-cial thermophilic bacteria, which producehydrogen while fermenting the material.The resulting gas can then be used, for in-stance, in a fuel cell to generate electricity.

“The tragic incidents in Fukushimahave further sparked discussions about al-ternative sources of energy”, notes Weder,“and tying this topic into current globalevents fascinated me and was an addition-al motivation.” Research has been con-ducted around the world for quite sometime to produce hydrogen from energycrops such as corn. Biogenic waste repre-sents an alternative that would be moresustainable.Cylinder head viewed by Empa’s computer tomograph.

Events9 January 2012 Seltene Metalle für ZukunftstechnologienEmpa, Dübendorf

13 January 2012Faserverbundwerkstoffe im Automobilbauund TransportwesenEmpa, Dübendorf

19 January 2012 Feinstaub – Inhaltsstoffe und QuellenzuordnungEmpa, Dübendorf

25 January 2012 Nanotechnologie für den Cleantech-BereichStade de Suisse, Bern

5 March 2012Holzforschung an der EmpaEmpa, Dübendorf

7 March 2012Nanotechnologie – Neue Materialienmit Chancen und RisikenEmpa, Dübendorf

16 – 20 April 2012 Intensive course: Nanopowders andNanocompositesEmpa, Dübendorf

26/27 April 2012 3-Länder-KorrosionstagEmpa, Dübendorf

12/19/26 June 2012Fahrzeugflottenmanagement –ganzheitlich betrachtetEmpa, Dübendorf

Details and additional events atwww.empa-akademie.ch

Your way to access Empa’s know-how:

As entrepreneur, I have

often sought collaboration

with Empa. I’ve thus

come to appreciate what

an exceptional perform-

ance they effect. Empa, to

me, is at the heart of

Switzerland’s knowledge

and technology transfer

network and a key to

our success in creating

innovations.

Federal CouncilorJohann N. Schneider-AmmannDirector of the Swiss FederalDepartment of Economic Affairs“

Opinion

Johann N. Schneider-Ammann

[email protected] +41 58 765 44 44www.empa.ch/portal”

empanews january 2012

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