Biweekly magazine of the Eindhoven University of TechnologyFor news: www.cursor.tue.nl and follow tuecursor on andmmJune 6, 2013 | year 55

University news22Second skin6Choices, choices2

4 | The new TU/e race monster

19

2 | For Starters June 6, 2013

Brainmatters

Choices, ChoicesMy local Albert Heijn offers a selection of 16 different types of eggs. In addition to quail eggs, they offer 15 kinds of hen’s eggs, including free-range eggs, EKO-eggs, ‘Happy chicken’ eggs (with 2 stars out of a possible 3, which begs the question what kind of chicken would score 3 stars out of 3: ecstatic chicken?), corn eggs, four grain eggs, grass eggs, biological (!) eggs, white eggs, etcetera. Not to mention the variety of egg trays in different shapes and sizes, and available in plastic, recycled cardboard, and bio-degradable materials. Although the core assumption here is that more freedom of choice leads to a happier customer (at least two stars worth of happiness), we also know that too many choice options can lead to a paralysis of sorts. With just ‘eggs’ scribbled on my grocery list, I’m staring at the eggy overkill that is on display, trying to decide what to base my decision on.

Research has demonstrated that having a lot of choice options does not lead to greater satisfaction, but rather the opposite: a nagging doubt about whether one has chosen correctly, and feelings of regret about the options left unexplored. This is particularly true for so-called ‘maximizers’ - people who need to be assured that their every purchase or decision was the best that could be made. Maximizers also tend to have unrealistically high expectations of the outcomes of their choices, which almost certainly leads to disappointment. People who settle for “good

enough” options, the so-called ‘satisficers’, do not worry too much about the possibility of a better option they may have missed. As a consequence, they experience less choice stress, and experience less regret afterwards. All this and more is described in ‘The Paradox of Choice: Why More Is Less’ by the American psychologist Barry Schwartz. Tomorrow, June 7, all bachelor students are expected to indicate their preferences in terms of the electives in their program. As a coach within the Psychology & Technology major I’m trying to add my five cents to the choice process students are faced with, although selecting from 87 coherent tracks, 10 USE-tracks and a host of individual courses is not an easy task. Many choices are impossible due to programmatic or logistic reasons, but still enough uncertainty remains. My advice: don’t worry too much about it. The perfect choice doesn’t exist (because how would you know you’ve made the perfect choice without having tried all alternatives?); the good enough choice does exist. And, paradoxically, this is what makes you happier in the end - certainly two stars worth, maybe even three...

Psychology is becoming ever more important at TU/e. Technical systems and artifacts, be they games, cars, robots, lighting systems or buildings, are all meant for human end users eventually. It’s essential to know how these users perceive, think, feel, and act. The new human-oriented program Psychology & Technology examines every technical design from a psychological perspective. From now on, Cursor will be taking a closer psychological look at students, teachers, labs, technical artifacts, the workplace, the scientific business, campus, education, and websites.

Wijnand IJsselsteijn, full professor Cognition and Affect in

Human-Technology Interaction. Photo | Bart van Overbeeke

ColophonEditor in chief

Han Konings

Executive editor Brigit Span

Editorial staff Judith van Gaal

Tom Jeltes | Science Frits van Otterdijk

Norbine SchalijMonique van de Ven

Staff Nicole TesterinkGerard Verhoogt

Photography Rien Meulman

Bart van Overbeeke

CoverBart van Overbeeke

TranslationAnnemarie van Limpt (pages 2,3,6,7)

Benjamin Ruijsenaars (page 4,5)

LayoutNatasha Franc

Editorial boardprof.dr. Cees Midden

prof.dr. Hans NiemantsverdrietAngela Stevens- van Gennip

Thomas ReijnaertsArold Roestenburg

Anneliese Vermeulen-Adolfs

Address editorial officeTU/e, Laplace 0.35

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Leonardo and Lex

Large part of this Dutch edition of Cursor is dedicated to the Bachelor College, which is about to celebrate its first anniversary. This year has seen the maiden voyage of the BC, if you will. In 2011, dean Lex Lemmens was heralded as captain and was assigned the task to put the ship together in and launch it already on September 1, 2012. He’s spent the past year trying to keep the brand new ship on course.

Maiden voyages have a history of ending badly. Ships sink or explode, the captain stays on his ship until the very end, and the majority of crew and passengers become fish food, quite literally. The first and only voyage of Titanic may be the most appealing example of one of those disastrous enterprises. Pride always goes before a fall, and in the movie even Leonardo DiCaprio couldn’t change the course of events.

Reading the interview with Lemmens, the threatening icebergs floating past the BC are almost tangible. Some departments even consider to take the rudder in their own hands again. At times, one of the ship’s

Wow... That was a long and active weekend! My skin finally got a chance to tan on ‘SUNday’ and my mind got much less sleep than usual. Nevertheless, it was fed with beautiful music and smiles of people visiting the event I was working at. Last weekend brought us the Music on the Dommel festival. It was the fourth edition, actually. People might say the event was a success because of the weather, but the credits go to a team of strong, friendly and enthusiastic people, really: the volunteers (ranging from festival board members to guards).

This year Muziek op de Dommel had a lot of international volunteers, mostly alumni or current students of TU/e, and the fact brought a smile of satisfaction to my face. After four years of waiting and hoping all the efforts to unite foreigners and locals in Eindhoven would work, finally internationals were actually taking part in the city community. What I mean is this: volunteering at the festival was not only a great input for one of the largest free cultural events in Eindhoven, but it also had a wonderful influence on

the volunteers’ social circle. International people working on the festival grounds had a chance to mingle with the Dutch and meet many other nationalities, to make new friends and even enjoy the afterparty on Saturday night. I hope to see even more international volunteers joining the great Music on the Dommel team of volunteers next year, and I expect more and more events like this will help us to unite people living together in this exciting area.

Indre Kalinauskaite, User System Interaction trainee at ID department

Weekend of Music

bulkheads was open (in the form of an interim test) and the ship made so much water it lost its balance. Still, Lemmens is a dedicated captain and he managed to close the partitions in time. Pride is not an issue here; he’s realistic and knows what went wrong as well as what should improve next year. Here’s to hoping the icebergs melt considerably before next year starts.

Our Rewwwind feature provides you with snippets of last week’s news. What happened online after the previous Cursor magazine was published?

4 June 2013 - TU/e’s MetaForum building, designed by Ector Hoogstad Architects, has won the ‘Gulden Feniks’ (golden phoenix) in the category Trans-formation. MetaForum had already received an honorable mention at the

Building of the Year contest, and it has been nominated for the LEAF Award, an international prize that will be awarded in September.

31 May 2013 - The presentation of the URE08, the latest car made by University Racing Eindhoven, didn’t go exactly as planned on May 30. During a demonstration on the Green Strip in front of the Auditorium its direct

predecessor URE07 skidded and ended up in the crush barriers. There was no damage or casualties, but it left the audience startled.

MetaForum wins ‘Gulden Feniks’ for best transformation Presentation racecar URE not entirely flawless

www.cursor.tue.nlRewwwind

Clmn

Han Konings, editor in chief Cursor

Last Sunday, June 2, some 4,500 children and adults visited

the TU/eXperience Public Day. At 4 locations on campus the

audience could enjoy a total of 26 activities. Experiences

included cuddling with 5 dinobots, and soldering 200 little

DIY robots. Visitors took home about 300 tubes of self-made

toothpaste, 260 visitors had their 3D picture taken, and URE

took 500 polaroids of children in their race car. And the ‘longest

nylon thread’ competition record (created from a fluid interface)

was set at 30 meters.

When TU/e was still the Technical University of Applied Sciences,

this day was called ‘Days for the Commons’. Later this was changed

to Public Day, which already saw its 22nd edition this year.

No less than 386 students and staff members helped out to

make the day a success. (MvdV)

An experience for the commons

For Starters | 3See for more news www.cursor.tue.nl

Photos | Bart van Overbeeke

Vox Academici

How important are supercomputers in unraveling protein structures?

Dr. Heiner Friedrich, assistant professor of Materials Interface Chemistry, Department of Chemical Engineering & Chemistry

Heiner Friedrich. Photo | Bart van Overbeeke

“The use of supercomputers in this area of expertise isn’t entirely new”, says Heiner Friedrich, associate professor of Materials and Interface Chemistry of the Department of Chemical Engineering & Chemistry. Being one of the researchers of the Soft Matter Cryo TEM Unit, he’s already using high-tech electron microscopy regularly. “We’ve been making simulations based on high-

resolution cryo- electron microscopic images for a while now. It’s the huge dataset that makes the study special. More than 60 million atoms were modeled; you simply can’t calculate all that without the use of a supercomputer. And it will only come to be used more often in the future, because we want to be able to structure ever bigger and more complex structures. Computers are often the limiting factor in that respect, but luckily developments are rapid. After all, the

computer that’s on your desk today was the supercomputer of the 80s…”

“Of course the fact that this involves the aids virus doesn’t go unnoticed. But looking at it from a purely technical viewpoint, it’s no mean feat either, especially as far as the upgraded resolution is concerned. Previously, this type of structure could generate a resolution of 1.6 nanometers, but now they’re able to display images with a resolution of 0.8 nanometers. And a reduction by a factor of two is ten times as complex. Reading the reconstruction definitely makes your scientific heart skip a beat - it’s brilliant.”

“In the world of material sciences we also use simulations, albeit on a different level. Cells have the advantage of being able to synthesize proteins and protein complexes, which can subsequently be studied in detail.

But polymers can’t be created with atomic precision. Besides, we’re usually interested in the larger aggregates anyway. Although we do need quite some calculation power, we can still do without supercomputers easily. Our challenge is of a different nature. Most material scientists put ‘dry’ material under their electron microscope, which is fairly resistant to the electron beam so it can be studied for hours on end. However, the nanoparticles we work with are in a solution, so they are extremely vulnerable, and on top of that they can be shaped differently. It’s therefore all the more challenging to make proper models out of those. Because that’s what it’s all about, eventually, like the Nature article stated as well: you’re producing a structural model that serves as a starting point for hypothesis-based research. It provides an image of what you’re studying, and from there you can start asking more in-depth questions. And that’s an important step forward for science, surely.” (NT)

“This definitely makes your scientific heart skip a beat”

For the first time ever, the chemical structure of the HIV-1 coat protein - a jigsaw puzzle of approximately 64 million atoms - has been exposed in detail. In an article published in Nature last week, American scientists describe how the 216 hexagons and 12 pentagons are ordered exactly. It’s a spectacular find that can further the development of new medication for the virus that causes aids. Still, most media sources seemed even more interested in the performance of supercomputer Blue Waters. Are its calculation skills really that special, and will its services be used for the unraveling of all complex protein structures from now on?

4 | Focus June 6, 2013

URE08: few

Chassis | Through a clever use of the strong points of the materials, URE can build an enormously light yet safe chassis. While the team has been using this method for many years, only this year the whole chassis has been manufactured of carbon fiber with an aluminum honeycomb structure.

Text | Frits van OtterdijkPhotos | Bart van Overbeeke en URE

It was a non-stop job in the past few weeks, burning the midnight oil. Still, thanks to its strenuous efforts the student team of University Racing Eindhoven (URE)

managed to meet the deadline. On Thursday May 30 the latest electric racing car could be presented to

a big audience at the MetaForum: the URE08.

The chief feature of the fast racing car is its low weight. The builders claim that the car weighs less than one hundred and eighty kilos. In contrast to its electrically powered predecessors, this is a weight reduction by approximately sixty kilos. Team Manager Bram van de Schoot of the University Racing Eindhoven (URE) team: “In the past, the weight was never our major concern because the racing car more than made up for that in other respects. This year we focused particularly on building a lighter version. All our team members were asked to try and save weight wherever this was possible, and we have succeeded very nicely in this.”According to simulations the car should be able to accelerate from zero to one hundred km/h within three seconds. With the electric motor taken over from the URE07 (100kW and 136 h.p.) a top speed of 135 km/h should be possible. From August 1 thru 4 the URE will take part in a match for student teams on the German Hockenheim track. From August 29 thru to September 1 the URE08 will appear on the Circuit de Catalunya near Barcelona. After all the hard work, that will be a welcome bonus for the students from various departments of TU/e, Fontys Hogescholen and HAN Hogeschool in Nijmegen/Arnhem.

http://universityracing.tue.nl/

Focus | 5See for more news www.cursor.tue.nl

Suspension | This year URE switched from a highly complex multi-link suspension to a slightly less complex double wishbone suspension. The reason is that this allows more students to gather knowledge about the suspension. Apart from this, the URE will have Formula 1 shock absorbers mounted on its car.

Wheels | Most of the slimming operation is to do with sponsor and tire supplier Apollo. Vredestein was taken over by Apollo last year, which enabled URE to reduce their individually designed tires to 10 inch. The choice of smaller tires yields a total saving of some twenty kilos. These individually designed Apollo R&D tires make URE legendary in the competition. There are only two teams worldwide that use their own racing tires.

Batteries | The team has switched to other battery cells. These provide more energy per kilo. This choice results in a further weight-saving of circa fourteen kilos.

kilos, lots of temperament

6 | Research June 6, 2013

Johan Hoefnagels in front of the electron microscope containing the nano tensile. Photo | Bart van Overbeeke

Research | 7See for more news www.cursor.tue.nl

Second skin

The developments in the semiconductor industry result in ever smaller, faster, and more advanced electronics. The disadvantage of these silicon chips is that they’re fitted on hard, hardly bendable PCBs (printed circuit boards). It’s one of the reasons the industry is working on flexible, plastic electronics – a development that should pave the way for rollable displays. However, flexible does not necessarily mean stretchable, says Johan Hoefnagels. “Take this sheet of paper. I have no trouble rolling it, but I can’t bend it more ways than one at the same time. Paper is flexible, but not stretchable like rubber.” Only stretchable materials are suitable for covering surfaces that are bent in several directions, like an (eye)ball or irregular shapes like a heart or other organs. Moreover, stretchable electronics move completely in synch with transformations occurring when a heart beats, for example.

Stretchable electronics offer endless possibilities according to Hoefnagels, in the biomedical arena especially. “Anything is possible, really. A stretchable, electronic skin may be wrapped around a heart as a pacemaker, or to train the heart therapeutically. The brain may even be dressed with an electronic skin. It’s thought to be able to predict and even prevent seizures. You could even wrap it around nerves, and connect it to a bionic arm prosthetic.”

Today, the active components in silicon chips are so small - no more than several dozen micrometers - that they can easily bend along with a rubber surface. It does mean the rigid pieces of electronics will be further apart, though. And that’s exactly the problem, according to Hoefnagels: “It means the electrical connections between the components have to stretch even further in order to compensate for the rigidity of the silicon chips. And since there’s only limited space available for these connections, it means they have to be able to stretch extremely.” Such stretchability can be realized by having the wires ‘meander’ like a winding river. The material of the wiring, e.g. copper, barely stretches. But if the wire is sufficiently thin it is highly flexible. Because of the structure, the wiring behaves like a spring of sorts. If it’s stretched to more than fifty percent of its original length however, the wiring detaches from its rubber base. In order to inflate a flat device like a balloon completely, which is what Hoefnagels wants, the wiring has to be able to stretch to five hundred percent of its original length.

To tackle that very problem, Hoefnagels, who graduated from Applied Physics at TU/e and after a stint abroad ended up at Mechanical Engineering, already received a Veni Grant once. “For my Vidi research, I want to use microelectronics for stretchable uses on a tiny scale. The Veni research involved larger structures, applications of which are a stretchable pressure sensor array for car seats that provided the right back pressure automatically, and uses on airplane wings to monitor damage.”

As mentioned before, these stretchable structures came loose from their rubber base. “During my Veni research, it proved helpful to apply a semi-elastic buffer between the rubber and the electronics. But then I figured it might be even better to have the wiring actually separated from the base as much as possible.” Hoefnagels wants to hang the wiring from minute poles emerging from the rubber, not unlike power cables suspended between pylons. “That solution lies at the heart of my Vidi proposal.”

Hoefnagels will be working closely with Ronald Dekker, researcher at Philips and part-time professor at TU Delft. At Philips, Dekker developed an ultrasound detector measuring several millimeters meant for keyhole surgery. Hoefnagels explains that detector will function as a demonstrator for the Vidi project. “Right now, the ultrasound detector is made with flexible electronics that are fitted onto a rigid casing. Now what we want to do is make those electronics stretchable so the detector surface can be inflated to a near-balloon shape. That way, it can be used to look in all directions at once.”One of the major advantages is that when not inflated, the detector can be inserted through a tiny cut in the skin. The 3D option doesn’t need to be

activated until the detector is close to the respective organ after having traveled through a blood vessel, for example. Activation involves inflating the membrane into a ball with the detector chips. “The detector could be sent down the esophagus to have a look behind the heart. That way, surgery wouldn’t even be necessary.”

To make that happen, Hoefnagels wants to connect the dozens of microchips that compose the ultrasound detector through wafer-thin, winding wires made from the purest copper. They can’t be wider than several hundred nanometers. “With those dimensions, the wire should have the desired mechanical characteristics, more or less”, he explains. Microfabri-cation of such tiny structures calls for lithography techniques on a flat surface. Still, the wiring will be designed to move away from the surface upon stretching.

The trick is to remove the silicon surface and move the microchips and wiring, including the tiny pillars, to a rubber surface. For this step Hoefnagels will be working very closely with Ronald Dekker of Philips. “Philips is an important contributor to the project; we’re free to use their clean room for almost 200,000 euro, and then there’s the 800,000 I received from NWO.” The process they’ve planned is unique in the world, he believes. His competition focuses

primarily on larger structures. “There’s a group in the US that does comparable research, but they work with rubber from the very first step in production, and that material just has a lot of downsides.”Hoefnagels will use the Vidi Grant to appoint a doctoral candidate to test the stretchability of the wiring. It’s quite the specialist job considering the wire is so thin it’s not even distinguishable with an optical microscope. Hoefnagels’ Mechanics of Materials group therefore decided to develop an ultra-sensitive nano tensile that can measure what’s under the electron microscope. Another doctoral candidate will simulate the measurements on the computer. In the final phase of the five-year project, a postdoc will fit the stretchable electronics into the ultrasound detector.

Hoefnagels, a material mechanics expert, will be the pivot of the project. Eventually, he’ll have to connect all the pieces of the puzzle, which should result in a unique product with endless potential uses. As a way of saying goodbye, at the end of the interview he mentions several other uses. “An electronic skin for robots wired with a bunch of sensors regulating pressure, temperature, proximity, stretchability et cetera, for example. And a stretchable CCD detector can create an artificial retina for the eye. The latter has non-medical implemen-tations as well. High-quality cameras require expensive lenses that correct lens errors. Eyes don’t need correction, because the retina isn’t flat, but part of a ball. That implies that a bent CCD consisting of stretchable electronics would make for much better cameras in mobile phones, for example.”

Interview | Tom Jeltes

State-of-the-art electronics, integrated in stretching material that can be used as a sort of second skin to cover the heart,

the brain, and nerves, or even as an artificial retina. Dr.ir. Johan Hoefnagels hopes the invention will allow for all kinds of futuristic

medical uses. Last month he was awarded a Vidi Grant to make his dream come true.

The possibilities of stretchable electronics are endless

Mechanics of Materials developed a special, ultra-sensitive nano tensile