The magazine for reseach and innofation (Spring 2003

7/30/2019 The magazine for reseach and innofation (Spring 2003

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s

Spring 2003

S E C U R I T Y

M A T E R I A L S

H E A L T H C A R E

A Question of Identity

Invisible Revolutions

Before Illness Strikes

T H E M A G A Z I N E F O R R E S E A R C H A N D I N N O V A T I O N

Pictures of the Future


2/43

Scenario 2015:Hidden Wonders

Intelligent Materials: Invisible Revolutions

Adaptronics: New Materials Take ShapeBioengineering:Surprising Symbiosis

Nanotechnology: Great Oaks from Little Acorns

Facts and Forecasts: Nano 101 The Economics of the 21st Centu

Interview with U.S. Nobel Prize Laureate Prof. Richard E. Smalley

Interview with British Nobel Prize Laureate Prof. Harry Kroto

Combinatorial Chemistry: In Search of Substance

Innovation News: Mars Lander, PDA Navigation, New Cell Phone Ide

Research Partnerships:How to Mail a Smile

Transrapid: Only Flying is Faster

Patent Researchers: Ultrasound Diagnostics, Fuel Injection Technolo

Interview with Guido Grtler: Committed to International Standards

Feedback / Preview

Even or especially in a difficult market environment, an old sayingamong savvy entrepreneurs remains valid: Innovations are always indemand, whether as a tool for reducing costs or a means of increasing sales

and achieving higher returns. Today, those who fail to launch the right new

product at the right time will be punished on the market more severely thanever before. There are also additional challenges to be met, such as achieving

a global presence while retaining the capacity to respond to local market

demands or responding to the pressures generated by up-and-coming

firms from countries such as China, which not only operate with cost advan-

tages, but also have highly educated and qualified workforces.

Siemens is in an excellent position to meet such challenges. Innovationshave always been one of the foundations of our success and are thereforea core element of our corporate culture. Siemens invested 5.8 billion euros in

research and development in business year 2002. Altogether, 53,100 men

and women work directly on enhancing our innovative power, putting us at

the top of the patent rankings in Germany, Europe and the U.S.

Nevertheless, promoting innovation in a strategic manner and turning itinto business success requires continual effort at all levels. This involvesrepeatedly asking oneself the following questions: Are we taking the right

approaches to ensure that we not only recognize trends but also establish

them? Are we sufficiently exploiting the synergies available to such a broad-

based company? Are we using our resources efficiently? Is our project man-

agement organization effective enough from the initial idea all the way to

marketing? And, finally, are we developing a sufficient number of innovation-

focused managers?

Siemens developed the Pictures of the Future method as a means ofaddressing such questions as described in the October 2001 issue ofthis magazine. But thats not all. As part of our top+ Business Excellence Pro-

gram, we are making use of a number of tested instruments for strengthen-

ing our innovative power, including top+ Trendsetting and top+ Innovation

Benchmarking. The latter enables us to see how our own innovative ability

measures up to that of our strongest competitors. With the help of innova-

tion radar, we can identify the potential for improvement and develop new

approaches to solutions for example, in cross-Group cooperation , knowl-

edge management, idea development and evaluation, as well as employee

motivation and development.

In addition, we have extensive experience in establishing international net-works, as illustrated by our partnership with Tsinghua University in Beijing(see p. 30). Finally, the articles in the Materials, Security and Healthcare

segments of this issue clearly demonstrate that the measures described

above have succeeded in ensuring that Siemens remains one of the worlds

leading innovators.

InnovationsAre Alwaysin Demand

Prof. Dr. Klaus Wucherer

is a Member of the

Corporate Executive

Committee of SiemensAG and is, among other

things, responsible for

the top+ Business

Excellence Program.

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PICTURES OF THE FUTURE E D I T O R I A L

Cov

e

r (top right): When color strips

are projected onto aface, the result-

ing pattern can be used to deter-

mine the faces 3D structure - and

thus confirm the persons identity.

Bottom left: A photo detector con-

sisting of fullerenes nanometer-

sized soccer balls made of carbon.

M A T E R I A L S

P I C T U R E S O F T H E F U T U R E C O N T

F E A T U R E S

Scenario 2015:How to Catch a Thief

Biometric Applications: A Question of Identity

Biometric Technologies: Body Language

Interview with Prof. Christoph von der Malsburg: Face Recognition

Facts and Forecasts: The Next Mega-Market

Smart Cameras:Getting the Picture

Sensor Networks:Sensors That Organize Themselves

Data Networks:Viruses, Worms and Hackers

Interview with Marc Rotenberg: Privacy or Security?

S E C U R I T Y

Scenario 2010:An Ounce of Prevention...

Imaging Trends: Before Illness Strikes

Interview with Prof. Jrg Debatin: A Picture of Health

Software Solutions: A Uniform Imaging Interface

Telemedicine: Getting Well with the Web

The Sooner the Better wit h Molecular Diagnostics

Facts and Forecasts: Tapping Markets for Tiny Labs

Interview with John Clymer: Does Preventive Medicine Pay?

Interview with Dr. Sue Barter: Why Screening Saves Lives

H E A L T H C A R E


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Here's a date to mark in your calendar: December 23, 2003. That's when the

Beagle 2, the lander of the European Space Agency's Mars Express Mission, will

separate from Mars Express, parachute through the thin atmosphere, and touch

down on the Red Planet. Expected to be launched in May, the 34-kg lander will

carry a highly integrated package of environmental sensors, cameras,

microphones, spectrometers, sample collection systems and communications

gear. The key instruments will analyze soil samples, rock and the atmosphere to

seek signs of past or present life. To ensure the success of the mission, these

extremely sensitive instruments will have to reach their target an area in the

northern hemisphere with only a gentle impact. To accomplish this, the lander

must deploy gas-filled bags at exactly the right altitude to cushion its contact with

the surface. The gas bags, which will wrap themselves around the lander, will be

fired by a device called a Radar Altimeter Trigger developed by Roke Manor

Research (RMR), a UK-based business owned by Siemens. This 400-gram sensor

can measure distances to within less than 13 centimeters at an altitude of up to

100 meters above the surface. Whats more, it functions even under the planets

most adverse atmospheric conditions. RMRs radar sensor was selected for this

mission by the European Space Agency (ESA) because of the Siemens

researchers expertise and experience in the field of sensor technology. AFP

At CeBIT 2003, Siemens engineers

presented a cell phone that doubles as a

virtual mouse. A camera built into the

back of the phone tracks the motions of

a stylus held behind the phone,

interpreting the image of the stylus tip

as a mouse pointer, which appears as a

red dot on the phones large-format

color display. The red dot moves

synchronously with any movement of

the stylus. The pointer can be used to

select numbers or to input graphic sym-

bols. The virtual mouse can also be used

to play games that could not be imple-

mented on cell phones until now. NA

Museums, airports, factories, univer-

sities. Our society is full of huge groups

of buildings that can seem almost as

complicated to sort out as the mythical

Labyrinth at Cnossus. Yet quicklyfinding your way through modern

mazes may soon become child's play

thanks to a system called Enterprise on

Air now being tested at Siemens. Like a

personal guide, the system directs users

equipped with a wireless, mobile

Windows CE terminal such as a PDA,

smart phone, or webpad to a desired

destination. It accomplishes this feat by

using broadband technologies such as

Siemens engineers have invented a

space-saving roll-up display for cellular

phones. The display is about 0.3 mm

thin and contains electrochromatic

molecules that can change from

colorless to blue when a voltage is

applied. At CeBIT 2003 in Hanover,

Germany, researchers also demon-

strated a screen that can display several

pictures in a sequence. NA

Landing on Marswith a Gentle Bounce

Cell Phone Is a Virtual Mouse

Your OwnPersonal Guide

Ready to Roll

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PICTURES OF THE FUTURE I N N O V AT I O N N E W S

Experts at Siemens Automation and Drives Group have developed a miniature

laboratory that continuously monitors fluid processes. Potential beneficiaries

include brewers, who, until now, have had to withdraw samples manually in order

to monitor the status of fermentation. Furthermore, sample analysis has relied on

the use of expensive equipment in a laboratory setting. By providing continuous-ly updated information every few minutes, the new "lab on a chip will vastly

simplify process control. At the heart of the mini lab is a process based on capillary

electrophoresis in which liquids are decomposed into their component parts in

electric fields. This process takes place in a system of minute tubules that analyze

only a few billionths of a liter. The entire system is small enough to fit on a credit

card. NA

wireless LAN or Bluetooth. GPS is used

for positioning outside buildings,

whereas infrared signals are used

inside. Unlike GPRS/UMTS services, the

emphasis here is on access to the local

broadband network, combined with

much greater precision in positioning

than is possible in mobile phone

networks. Regardless of whether the

user is a maintenance engineer trying

to track down a defective pump or a

visitor searching for an out-of-the-way

conference room, users share the same

spontaneous access to locally available

data. AFP

In a few years, your car may be a

actually show you how to get to w

you want to go. A navigation co

developed by researchers at Sie

VDO Automotive uses augmreality the fusion of rea

computer-generated pictures t

the guesswork out of driving

system uses a tiny video camera lo

behind the rear view-mirror to

tinuously monitor the view ahea

camera's output, which appears

navigation monitor, is augmente

graphic processor that uses

regarding the vehicle's position

route to highlight the section o

Cars that ShoWhere to Go

Labon a Chip

the vehicle will need to follow

display could also incorporate fe

such as three-dimensional a

Naturally, it will be supporte

corresponding audio instruc

Impractical map representations w

a thing of the past. Researchers ca

however, that, because of the

number of calculations requir

superimpose real-time directio

video images, as well as the ne

develop a flawless man-ma

interface, a great deal of add

work will be needed before augm

reality can hit the road.

Demonstration of a flexible

display. Electrochromatic

molecules change color when

voltage is applied.

An augmented reality image of whe

car needs to go is superimposed on

images of the vehicles actual locati

A built-in camera converts a mov-

ing stylus behind the cell phone

into a pointer on the display.

The European Space Agencys

Beagle 2 is expected to touch down

on the Red Planet on December 23.

Enterprise on Air uses wireless

technologies to guide visitors to their

destinations.

A few billionths of a liter is

all it takes to analyze the

contents of a liquid such as beer.


4/43

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Hidden WondersMay 2015. Michel Louis is a professor of bio-organic

nanomaterials science who lives in Paris. Since he retired,

hes had more time for his favorite hobby telling people

in the local caf about the wonders of materials.

Iwas involved in materials researmore than 40 years. It started back1990s with the discovery of fullerene

Dieu, that was a new kind of material

of like soccer balls made of pure carbo

a hundred million times smaller. Th

fascinated an entire generation of ch

And after some German astrophysicis

was actually trying to make artificial in

lar dust succeeded in producing a large

ber of fullerene molecules, well, just

S C E N A R I O 2 0 1 5 M A T E R I AMATERIALHIGHLIGHTS

Small Worlds Quantum Harvests

Interview with Nobel LaureateRichard Smalley on the opportuni-ties and risks associated withnanotechnology.

Great Oaks from Little Acorns

Nanotechnology is coming ofage. Particles one-millionth of amillimeter in size will help re-searchers improve surface prop-erties and develop vest-pocket-sized supercomputers.

In Search of Substance

Thanks to automatic analysesand computer simulations at theatomic level, it will be possible todiscover new materials muchfaster than in the past.

Surprising Symbiosis

The marriage of biology and

technology will give rise to nervecells on silicon and gas-detecting proteins.

New Materials Take Shape

Future materials will be capableof adapting to their environmentand counteracting unwantedvibrations.

Page 23

Page 26

Page 12

Page 15

Page 18

Magnetic layers for

smaller memory chips

Piezomats counteract

annoying vibrations

Hip joints of biocom-

patible materials

Foamed magnesium is

light and stable

Fuel cells provide

power for cell phones

LEDs compete with in-

candescent light bulbs

New notebook displays

use nanotubes

2015

Dateline Paris, 2015: The cafes and

boulevards havent changed much.

However, new invisible materials are

now integrated in many everyday ob-

jects. Applications include foamed

magnesium in lightweight bicycle

frames, biocompatible materials in ar-

tificial hip joints, nanotechnology for

mini fuel cells, notebooks and brightly

illuminated displays, and piezofoils

that actively control car roof vibrations.


5/43

M A T E R I A L S S C E N A R I O 2 0 1 5

every research institute and university went

crazy. We did too. It was really exciting re-

search. And it was only the beginning, be-

cause right after that a Japanese scientist in-

vented nanotubes tiny cylinders that are

also made of carbon, sort of like rolled up

graphite. Nanotubes soon replaced fullerenes

because you could do a lot more interesting

things with them much more easily.

Garon, would you bring me a glass of pastis,

please?

You see the man with the notebook at

the next table? That ultraflat display hes got

is based on nanotubes that are laid out like

blades of grass in a field. Each of the tubes is

about a nanometer thick and emits an elec-

tron beam that excites one pixel on the

screen. A nanometer is a billionth of a meter

how about that?

But nanotubes arent the only new mate-

rial that have been discovered over the last

20 years. Remember how you used to have

to wait for minutes for your computer to boot

up? No, youre too young for that. But thats

how it was. Man, did that take long! Today

you just press a fingertip on an identification

sensor that checks to make sure its really

you, and all the programs are on nest-ce

pas? Its the magnetic permanent storage

chips that do it. The computer knows exactly

what state it was in when the power was

turned off. As a result, you dont have to

shut down the computer anymore either

and that was an operation that sometimes

took even longer than booting it up.

The really fantastic thing about these

new materials is that theyre all over the

place, but you cant see them because theyre

hidden. You see that lady over there talking

on her cell phone? The phones powered by a

mini fuel cell, and its got plenty of nanotech-

nology in it too. Young people dont think

about these things anymore they just stick

a methanol cartridge into the phone once

every couple of weeks. When I was young,

we used to have to drag a battery charger

around.

Basically, everythings gotten a lot easier.

Look at the bicycle that courier over there

has. Just about all the parts are made of

nanostructured metal magnesia foam. The

stuff weighs practically nothing. But you

cant see that when you look at it. Its all on

the inside. This nanostructuring concept real-

ly did catch on amazingly quickly. I was one

of the people who played a role in its devel-

opment back then. The thing is that a mater-

ials ability to withstand stress doesnt change

even if you get rid of about half the atoms

but its got to be the right half, mon Dieu!

We learned a lot from nature. A bone, for

example, is very light but nevertheless stable.

And speaking of bones, take a look at that

fellow with the cane over there. Ill bet you a

pastis hes got an artificial hip. But thats not a

problem today. The things last forever with

the new materials theyve got, and theyre

absolutely biocompatible. Ill have one of

them myself, if I ever need it.

The best thing about the new implants is

that they adapt to the way theyre used over

time. Now thats intelligent material! Cars

have got that kind of material too. Dont be-

lieve me? Well, did you ever wonder why the

really expensive cars are so quiet inside? Oh,

youve got a cheap car? Well, Ill tell you any-

way.

Theyre quiet because the roof contains

an adaptive mat made of piezo fibers, which

are actually ceramic and stretch out or con-

tract when you apply voltage to them. That

makes it possible to dampen vibrations.

Theres a sensor that measures the interior

noise level and an electronic control system

that stimulates the fibers in a way that neu-

tralizes undesired frequencies. Naturally, the

system still lets you listen to the radio or your

favorite CD. Amazing, nest-ce pas?

You want to see a new material thats re-

ally visible? Just turn around and look at that

billboard outside and the lighting here in the

caf. Its all LEDs. Just ten years ago it would

have been unbelievably expensive to light up

an entire room with them. I tell you, the

good old light bulbs days are numbered.

These LEDs are fantastic they last forever,

can take on all different colors and get by

with hardly any electricity. Now thats what I

call a real technological revolution! Oh, Ive

got to go now. It was nice talking to you.

Take care of yourself. Au revoir.

ONorbert Aschenbrenner

I N T E L L I G E N T M A T E R I AL S M A T E R I A

Invisible RevolutionsWood, stone, ceramics for thousands of years people have made use of all

kinds of naturally available materials. But things are changing in a big way. Researchers

are now customizing materials for a variety of purposes, and theyre even doing it

at the atomic level. The future belongs to intelligent materials.

For thousands of years people had to

make do with the materials that nature

provided them with things like wood and

stone, and metals such as gold, lead and cop-

per. Even after the advent of iron forging,

clay furnaces and glass-making, it was nearly

two thousand years before any great leap in

materials science occurred. Materials re-

search as an independent discipline didnt

even exist 50 years ago, says Dr. Peter Paul

Schepp, Managing Director of the German

Society for Materials Research (DGM). Devel-

opment scientists basically used the materi-

als they could find in a catalog, he adds.

This situation has changed dramatically.

Our knowledge of materials has exploded

over the last two decades, says Rainer Nies

from Strategic Marketing at Siemens Corpo-

rate Technology (CT). Nies, a physicist,

headed a study of new materials. The study

found that although researchers in th

refined known materials for use with n

plications, todays materials sci

chemists, physicists and even biologis

computer scientists create customize

materials. And the future will bring

advances. Were on the verge of a n

an age of intelligent materials, say

The buzzwords of the future w

nanotechnology, bioengineering and

tronics. Researchers in the latter field

tempting to create materials that can

to various environmental conditions

example, construction support materi

can dampen oscillations by themselv

p. 12). Biomaterials include biopolym

tificial spider-silk fibers, biomorphic ce

made from materials such as cardboa

maintain the source materials basic

tures, and materials for medical applic

such as artificial tissue elements (see

Rainer Nies of Siemens Corporate

Technology uses ropes to demon-

strate advances in materials re-

search. Each one can hold three

tons. Yet their cross sections vary

from 22 millimeters in the case of

the hemp rope to six millimeters for

the high-performance polymer cord.

Hard drive vs. organi

molecules:

A layer of organic molec

can store 1,000 times m

data per square centime

than a hard drive.

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6/43

processes. For instance,

DGMs Schepp points to

superplastic forming, a

process that makes it

possible to significantly

reduce the cost of manu-

facturing components.

The final contours are

created in virtually one

step casting is the

only conventional tech-

nique that can accom-

plish anything similar to

this, says Schepp. Turn-

ing and milling are nec-

essary only for fine detail

work. Definitely re-

quired, however, is

thermo-mechanical pre-

treatment of the material

in a manner thats precisely tailored to its

properties. This treatment refines the grain

structure of the material to such a degree

that the grains flow like sand into the form,

which they then completely fill, requiring

only a maximum of ten percent of the pres-

sure needed with conventional methods. Su-

perplastic forming is a particularly suitable

technique for manufacturing medical im-

plants. An artificial thigh bone, for example,

consists of titanium alloys, which are very ex-

pensive and difficult to

machine. But when such

implants are produced

on a large scale, sub-

stantial savings can be

achieved because

milling-related waste

can be significantly re-

duced.

Experts agree that

successful materials de-

velopment today de-

pends on achieving a

new dimension in inter-

disciplinary approaches.

Not only do researchers

from various fields have

to work closely together

during every stage of

development; but the

individual components of a part must inter-

act in an optimized manner as well. It is also

very important that future users be inte-

grated into the process early on.

Ceramics Under Stress. A good example of

the successes that have been achieved in

modern materials research is a diesel injec-

tion system from Siemens that is controlled

by piezo crystals (bottom right). In piezoelec-

tric applications, a ceramic expands when a

voltage is applied. The injector exploits this

effect to open and close a valve, explains Dr.

Karl Lubitz from Siemens Corporate Technol-

ogys Materials Research department. Lubitz

developed the key component for the piezo

injector for automotive supplier Siemens

VDO. More than ten years of research went

into the piezo injector, which can pump a cu-

bic millimeter of diesel fuel at a pressure of

1,600 bars into an engine combustion cham-

ber in less than a millisecond. Such targeted

injection not only causes the engine to run

more smoothly and quietly; it also cuts fuel

consumption and emissions.

The injection component, which is

coated with a plastic, is extremely complex

it has 360 ceramic layers. Nevertheless, it

is only a small part of a system in which each

component is critically important for the

proper functioning of the whole.

Light bulbs vs. LEDs:

Red LEDs are three timesmore efficient

than conventional

incandescent light bulbs.


Nanotechnology ultimately focuses on indi-

vidual atoms that are maneuvered piece by

piece in a completely controlled manner to

create a material (see p. 18). Richard Smalley,

an American Nobel Prize laureate in chem-

istry, is convinced that nanotechnology in

particular will dramatically change the world

we live in (see interview on p. 23). German

experts share Smalleys view. According to a

study conducted by the Electronic Techno-

logy Association (VDE), microsystems tech-

nology and nanotechnology have the great-

est innovation potential, ahead of even

information technology and biotechnology.

Foamed Metal. Even without nanotechnol-

ogy, however, the ability to combine known

materials with new production methods

means that the amount of materials used in

industry will continue to increase. Foamed

lightweight metals, for example, could be

transformed into especially light, yet stable

components for aerospace or automotive ap-

plications. Such materials are very rigid while

weighing relatively little. Similar properties

are exhibited by composite materials contain-

ing fibers made of high-strength or very rigid

materials, such as glass or carbon, which are

incorporated into plastics.

The variety of materials can also be in-

creased through improved manufacturing

M A T E R I A L S I N T E L L I G E N T M A T E R I AL S

When we started this project, hardly

anyone believed we would be able to control

fuel injection using piezo ceramics, says Dr.

Andreas Kappel from Corporate Technologys

Microsystems department. But Kappel gradu-

ally succeeded in convincing everyone that

the technology would work. And its a good

thing he did. Siemens VDO is going to post

billions of euros in sales in the next few years

with this development, he adds proudly.

The technologys potential isnt even close to

having been exhausted. Kappel and his

team are now able not only to simulate a

functioning injector all the way down to its

microstructure, but can also observe it in op-

eration. This enables them to run numerous

tests to improve injection in a very short pe-

riod of time, without having to install the ac-

tual component in an engine.

From Simulations to Promising Mixtures.

Such computer simulations have become an

important tool in all areas of materials re-

search. They make it possible to predict how

materials will behave at various tempera-

tures, under load, and at different times

throughout their life cycles on the atomic

level and as a complete component. Further-

more, when it comes to finding the best ma-

terial for a particular application, mathemati-

cal models are rapidly replacing

trial-and-error techniques. Researchers can

use combination methods to study in one

process step a variety of mixtures of

chemical elements with regard to their suit-

ability, and they can then extract the most

promising mixture from

the vast amounts of re-

sulting data (see p. 26).

But even the best

supercomputer cannot

replace the experience

of a scientist. To be suc-

cessful, you need a team

that has a commitment

to continuity in its re-

search, says Dr. Bern-

hard Stapp, Head of Re-

search at Osram Opto

Semiconductors. And he

knows what hes talking

about, since his team of researchers is mainly

responsible for the increases that have been

achieved in the efficiency of light-emitting

diodes (LEDs). LEDs offer significant advan-

tages in converting electric current into light

(see graphic). Depending on the conditions

in which they are used, they can run for up to

100,000 hours. If left on ten hours a day,

they will continue to operate for nearly 30

years. They are also extremely robust, and

their efficiency rating is many times higher

than that of a normal light bulb. LEDs have

already replaced conventional technologies

in certain areas, such as

interior lighting for auto-

mobiles, and are set to

take over vehicle tail-

lights as well.

LEDs, which have a

chip-edge length of less

than half a millimeter,

have benefitted not only

from dr amatic improve-

ments in materials, but

also from special surface

structures. LED produc-

tion involves depositing

several crystalline layers

onto semiconductor disks at temperat

between 600 and 1,000 degrees C

Every single parameter whether te

ture, pressure, wafer rotation speed,

composition is critical for achieving

timal product that can also be pro

mass produced. A big problem with t

terials used in LEDs (gallium-indiu

minum-phosphide or gallium-indium-

is their extremely high refractive inde

is, most of the light produced is reflec

ward at the edge where the crystal me

air. Researchers have gotten around th

internal reflection problem by produ

surface with specially shaped profile

significantly improve the degree o

emitted. Improvements of this sort,

with constant material refinement, h

creased efficiency by a factor of 30

decade since 1970.

We have to do more than just fi

best phosphor, says Stapp. We also h

be able to recognize and control the co

relationships between materials, pro

and applications. Adds Karl Lubitz: T

team effort. A researcher working in is

would have no chance of succeedin

new materials. ONorbert Aschenb

0

0,01

0,1

1

10

1970 1975 1980 1985 1990 1995 2000 2

Luminous flux in lumenat a current of 20 mA

Material composition

GaAsP

GaAIAs

InGaN

InGaN

GaN

SiC

In

GaAIAs

GaAsP:N

GaP:N

InGaA

Copper vs. nanotubes:

Inch for inch, a wire made

of nanotubes conducts

electricity one thousand

times better.

L E D L UM I N OS I T Y H AS I N C RE AS ED B Y L EA PS A ND B OU

LEDs (left) and piezo injectors for diesel vehicles (right) are two shining examples of

successful materials development at Siemens. But its not just better materials that

count improved processing also plays a vital role.

Scientists have boosted the efficiency of LEDs by a factor of 30 every deca

since 1970. The graph shows the amount of light emitted by LEDs at a sp

fied current consumption, the colors that could be achieved at the time, a

the range of materials used. Source: Osram.

Ga: Gallium, As:Arsenic, P:Phosphorous, N:Nitrogen, Al: Aluminum, In:Indium


7/43

From fibers that register mechanical stress in airplane rudders to

automobile roofs and magnetic resonance tomographs that coun-

teract vibrations and cut noise a quieter, safer world is taking

shape thanks to developments in adaptronic materials.

Memory Metal in the Dishwasher. Only re-

cently, a memory metal actuator a wire

made of nitinol (a nickel-titanium alloy)

produced in Kautzs laboratory went into pro-

duction. The wire is part of an optical sensor

in the latest range of dishwashers produced

by Bosch and Siemens. This optosensor

measures the calcium content of the water

up to ten times during the dishwashing pro-

gram and uses this data to regulate the re-

lease of a special salt. The memory wire,

which is activated by a small jolt of electric

current, is designed to open a small valve

that expels water from the sensor. In the

process, the wire, which is ten centimeters

long, contracts by five millimeters and devel-

ops astonishing strength in spite of being just

0.25 millimeters thick. Because the wire au-

tomatically reacts to voltage changes, com-

plicated control technology is unnecessary,

says Kautz. All in all, the optosensor and its

entire mechanism is no larger than the small-

est pocket calculator.

Meanwhile, Siemens CT researchers are

working on integrating a sensor, an actuator

and a regulator into a single tiny component.

That would open up a new range of poten-

tial applications, says Holger Hanselka, direc-

tor of the Fraunhofer Institute for Structural

Durability (LBF) in Darmstadt, Germany.

Hanselka, who works at the University of

Darmstadt, is one of a handful of people

around the world who teaches adaptronics.

These compact and lightweight adaptive

materials are ideally suited for integration

into lightweight production materials, he

12 P ic t u res of t h e Fu t u re | Spr in g 2 0 0 3

New Materials Take ShapeThe thin, slightly bent metallic thread thatDr. Stefan Kautz is holding between hisfingers looks like a piece of ordinary florists

wire. But you only have to touch it to realize

that this wire is made of a very special mater-

ial. The metal feels soft and warm, like a

blend between a fishing line and a copper

wire. Kautz holds the thread over a flame.

Within seconds, the bent wire curls itself into

a perfect paper clip.

Kautz, a specialist in memory metals at

Siemens Corporate Technology (CT) in Erlan-

gen, Germany, is working on materials that

can remember the shape into which they

were originally formed. These substances

are evolving into a promising production ma-

terial that could open a new field known as

adaptronics the marriage of adaptation

and electronics.

Adaptronics engineers are after some-

thing new. They want to develop materials or

components that are so smart they can auto-

matically adapt to their surroundings. Under

ideal circumstances, these materials combine

sensors, regulators and actuators in a highly

compact space.

According to experts such as Siemens

Kautz, such materials are multifunctional.

That is, they can register alterations in their

surroundings for example, changes of

temperature and respond immediately.

The first prototype components of this sort

have already been produced. Memory met-

als are excellent examples of adaptronics,

says Kautz, who explains that If they are

heated or subjected to a voltage, they

change shape. They do this by means of a

simple, temperature-dependent alteration of

their atomic lattice structure no complex

electronic manipulation is required.

Piezofibers in airplane rudders

could detect cracksand significantly

simplifysafety checks.

P ic t u res of t h e Fu t u re | Spr in g 2 0 0 3

says. According to Hanselka, lightweight ma-

terials are the wave of the future in fields

such as automobile and airplane production.

However, due to their low mass, such materi-

als tend to vibrate, thus generating noise and

other problems. Adaptive materials can help

here, as they can register when a material

starts to vibrate. The sensors signal is

processed by a regulator, which then causes

time hardened into a gel by means of chemi-

cal reactions or changes in temperature. This

creates long threads which then gently coag-

ulate into crystalline piezofibers without

breaking. These fibers are so fine that they

can be easily integrated in lightweight com-

posite materials, says Dr. Dieter Sporn of the

Fraunhofer Institute for Silicate Research

(ISC) in Wrzburg, Germany, which played a

transmits an electrical pulse back to th

which then bends in a particular dir

The fiber generates a kind of count

that blocks the vibration in its early s

Combined with the appropriate so

this kind of closed-loop control can c

even large components.

Piezofibers and Quiet Cars. To fi

what kinds of future developments m

possible in adaptronics, scientists rep

ing over 20 companies and researc

tutes have been involved in the Adap

Pilot Project. The goal of this initiative

was supported by the German Ministry

search and concluded in late 2002,

develop components that could be u

create adaptronic products. One of th

ucts developed in the project was an

tive car roof made of lightweight m

that could effectively dampen vibrati

ing piezofoils and piezofibers. Accord

Hanselka, this technology is ready

next generation of vehicles. He e

however, that this kind of car roof will

be installed only in a small number

mium-segment vehicles.

Dieter Sporn believes that the fibe

have a future in the aerospace indust

example, the rudder units of todays

jets consist of composite materials.

M A T E R I A L S A D A P T R O N I C S

an actuator to dampen the vibrations

through countermovements.

In view of this, Hanselka and others are

placing high hopes in a new generation of

piezomaterials, which are true masters of

versatility. The materials can transform elec-

trical energy into mechanical energy and vice

versa. Some cigarette lighters, for example,

generate the energy that sparks the flame

from a piezocrystal that is put under me-

chanical pressure. A joint project carried out

by a number of Fraunhofer Institutes has suc-

ceeded in spinning piezomaterials into long

fibers that are only 20 to 30 micrometers in

diameter. In this process, the fibers are pro-

duced using the so-called sol-gel process.

The sol is a solution of molecules that is

pressed through tiny nozzles and at the same

key role in the development of this process.

In the past, piezo components were gener-

ally so big that they interfered with the struc-

ture of lightweight materials.

Both the new fibers and the piezo foils

that have long been in use can simultane-

ously fulfill the functions of a sensor and an

actuator. For example, if a piezomaterial is

activated by undesirable vibrations, it gener-

ates an electrical signal that can be inter-

preted by a controller. The controller, in turn,

tion of these units for hairline cracks a

den damage is a time-consuming proc

the rudder unit must be scrutinized w

trasound. Adaptive materials would

this process unnecessary. A me

piezofibers integrated into the materia

detect cracks that subject the fibers

chanical tension and directly transmit

formation to analytical software, says

adding that piezofibers could signi

simplify safety checks.

Metal with a memory.

A deformed paper clip returns

to its original shape when

exposed to flame.

Researchers at the Fraunhofer Institute

have succeeded in spinning ceramic

piezofibers into long, thin threads that

are ideal for adaptronic materials.


8/43

Ceramics with the microstructure of trees, nanocatalysts in bacterial proteins, nerve cells on micr

chips bioengineering is set to create a surpising symbiosis of nature and technology.

Surprising Symbiosis


It is a remarkably delicate architecture.Three elastic strands of collagen windaround each other in loops, forming neatly

stacked and networked spiral columns that

incorporate hollow spaces at regular inter-

vals. Tiny crystals of hydroxyapatite, a min-

eral containing calcium phosphate, are di-

rected to the correct locations in these

spaces, where they grow and fill the gaps.

The result is a living ceramic substance incor-

porating pores and channels where cells are

anchored in essence, a bone. The struc-

ture of the substance, a combination of soft

proteins and hard minerals, lends it charac-

teristics that at first seem contradictory. Bone

is hard but not brittle, rigid but flexible. It is

lightweight and porous, yet can bear consid-

erable mechanical loads. Stable and yet con-

stantly changing, bone can even heal itself. It

is truly a wonder of nature.

In recent years, researchers have been

studying the principles supporting such per-

fectly adapted biological structures, and ma-

terials developers are now trying to put that

research to practical use. Inspired by natures

capabilities, these experts are using cells, bio-

molecules and biological concepts to create

new materials. Nature has optimized its mat-

ter over millions of years were trying to

profit from that, says Rainer Nies, who is

working on potential applications in th

of bioengineering at Siemens Co

Technology (CT) in Erlangen, Germany

Researchers would like to duplic

ganic materials precise structuring,

can be measured in nanometers (o

lionth of a meter). Similarly precise sy

materials would make it possible to

miniaturize electronic and optical c

nents and enhance their properties.

stance, Prof. Peter Greil and his team

University of Erlangen are using biom

as templates for industrial materials.

process, Greils team decomposes a p

wood in a nitrogen atmosphere at

M A T E R I A B I O E N G I N E E R I N G

Electron micrograph of a sna

nerve cell. The cell is held in plac

on a microchip by means of plasti

studs, each of which is a mer

20 micrometers in size

Technology

Piezofibers,

polymers,

patches

Memory

metals

Electrorheo-

logical and

magneto-

rheological

materials

Magneto-

strictive

materials

Photo/

thermo/elec-

trochromicmaterials

Glass fiber

sensors

Hollow fibers

and micro-

capsules

How it Works

Mechanical stress is con-

verted into an electrical volt-

age and vice versa

Electric current or an increase

in temperature give rise to a

change in shape

An electrical voltage or mag-

netic field causes the re-

versible solidification of liq-

uids by making microscopic

particles in the liquid link up

Reacts with an increase in

length even at weak mag-

netic fields (similar to piezo)

Materials that change their

color or transparency accord-

ing to the effect of light, heat,or electric fields

External influences change

the propagation of light in the

fiber

Hollow fibers or capsules in a

material release fluid/active in-

gredients when they are

destroyed

A D A P T R O N I C A P P L I C A T I O N S T O D A Y A N D T O M O R R O W

Possible Applications

Damping vibrations in components (car bod-

ies, MR equipment, etc.); active changes in

sections of rotor blades and wings to cut

noise and save energy; increase in compo-

nent strength (active prevention of deforma-

tion); monitoring of component status when

used as a sensor

Actuators for valves or interlocks; damping

vibrations; components: memory metal con-

tact pads as microchip mounts that can be re-

leased by a change in temperature

Exact adjustment of shock absorbers to road

surfaces; hydraulic valves; control using tactile

joysticks (force feedback); movement control

of knee and joint prostheses

Use as actuators, sensors, vibration dampers

Climate-controlling windows that control the

sunlight coming into a building or a car;

changing the light-absorbing properties ofphotovoltaic

facilities

Detection of temperature variations, pressure,

mechanical stresses, vibrations, accelerations,

magnetic fields

Emergency lubricants in cutting or grinding

tools; plastics that heal themselves by releas-

ing liquid adhesive in hairline cracks

Existing Applications

Actuators for injection pumps and

valves, compact electric motors

Interlocks and valves made of

memory-metal wires, strips or

springs (e.g. dishwasher sensor);

medical instruments for

microsurgical procedures

Introduction of the first products in

the next months

Sensor for shop security

Prototype climate-controlling win-

dows and photovoltaic glass

Various prototypes

Self-healing materials; capsules

with emergency lubricants; wax-

filled capsules with a heat-insulat-

ing effect; corrosion prevention

Market Potential

Very high; many applications

in the near future

Increased degree of integra-

tion in complex electrical and

electronic systems in the next

few years; further use in

surgery

Growing potential in the next

few years

Mass-produced articles in a

few areas

Increasing importance, espe-

cially in the area of energy op-

timization for buildings

First applications in coming

years

Established mass-produced

item; a large number of new

products and applications in

the next few years.


M A T E R I A L S A D A P T R O N I C S

Adaptive piezotechnology can also help

to make driving safer. Prof. Hans Meixner,

head of the Sensor and Actuator Systems

Competence Center at Siemens Corporate

Technology Center in Munich, is developing a

new automotive sensor designed to ensure

that tomorrows airbags inflate correctly. To

this end, stretch measurement strips made of

piezofibers will be integrated into vehicle

seats. As the degree of stretching depends

on the occupants weight, passengers will be

better protected in the event of a crash. At

present, airbags inflate with the same degree

of force, regardless of whether a small child

or a heavy adult is sitting in the seat. Thanks

to the information provided by stretch mea-

surement strips, future airbags will inflate

with an intensity that will softly cushion each

passenger.

Quieter MR Scanners. Another promising

application area is medical electronics. For in-

stance, Dr. Hans-Georg von Garen and his

colleagues at CT in Munich and Erlangen are

working on piezofibers that can dampen vi-

brations in magnetic resonance (MR) tomo-

graphs. Because the magnetic field gener-

ated by these machines must constantly

change its direction as it moves along a pa-

tients body, forces are generated that cause

the funnel of the patient entry tube to vi-

brate. At 120 decibels, the resulting noise

can be as loud as a jet plane taking off. The

worst problems are caused by low frequen-

cies, which disturb not only the patient inside

the MR machine, but also medical personnel.

Garen and his team hope to dampen these

vibrations by using numerous strips of piezo-

foil the size of small bandages. When glued

to the funnel, the strips of fiber act as sensors

and actuators simultaneously. The challenge

is to determine exactly how the funnel is vi-

brating at a given time, and how the vibra-

tion dampers can be precisely controlled.

O Tim Schrder


9/43

However, such growth can take place

only if the physical and chemical conditions

in the reactor resemble those in the human

body. This in turn requires the presence of

numerous sensors and sophisticated con-

trols. If you want to grow a bone implant, for

example, the cells must be put under pres-

sure, just as they are under natural condi-

tions in an organism. Only then will they be

stimulated to grow in the desired direction.

Pompes group is trying to generate this pres-

sure with the help of tiny piezo actuators that

vibrate at high frequencies. These actuators

are very similar to the structural components

that Siemens produces for direct fuel injec-

tion in diesel engines (see p. 9). The rapidly

increasing demand for tissue produced by

biotechnological means is in any case a

strong incentive to overcome any difficulties

that still remain, according to Pompe.

Nerve Cells on Microchips. Even more so-

phisticated approaches are being pursued in

an attempt to unite living cells and technical

components for example by combining

nerve cells and semiconductor electronics.

The long-term goal is a hybrid neurochip that

could be used to build neuroprostheses such

as those that would enable blind people to

see again. Another possibility would be a

In other words, the nerve cell and the chip

communicate with each other, and they do

so in a manner that does no harm to either

of them. When connected to a pond snails

nerve cells, a silicon chip of this kind will

function for weeks or even months.

But thats only the beginning. As soon as

you have a network of roughly 100 neurons,

in which each individual neuron can be mon-

itored or selectively stimulated, it will be pos-

sible to experimentally test the basic con-

cepts of brain research for the first time ever.

A number of theories today attempt to ex-

plain how living neural networks function,

Fromherz doubts whether researchers

able to connect more than ten neurons

next five years.

Fromherzs team is therefore pur

parallel strategy that promises faster

They are using naturally grown neur

works consisting of sections of rat

connected with microchips. One prob

that the rat neurons cannot be triggere

vidually, only in groups. The scientists

cusing on the hippocampus, the area

brain that plays a key role in learnin

neon has built a semiconductor chip c

ing 10,000 transistors to meet the s

needs of these experiments. The rese

can use the chip to investigate the ac

of nerve cells at previously impossible

tions. Fromherz has high expectatio

their research. Id like to use the bra

tions as a learning network controlle

microchip, he says. Such basic resea

believes, will make it possible to find o

nerve tissue communicates with micro

The results of such research could,

ample, help speed up the developmen

artificial human retina. Although the c

of an electronic eye may still lie far

future, bioengineering is already

tremendous strides. Whether its nan

lysts in bacterial proteins, artificial bo

artificial organs bioengineers are c

materials with previously undrea

properties. These materials are well o

way to creating a new symbiosis of

and technology. OCarola H

Prof. Peter Fromherz is studying how nerve cells talk with silicon transistors.

A chip with real nerve cellscould not only

help us to understand the brain it could

also help us to reproduce it in miniature.

neurocomputer that combines the capacities

of biological and electronic intelligence.

Prof. Peter Fromherz at the Max Planck Insti-

tute of Biochemistry in Martinsried, Germany

have already succeeded in making two or

three neurons grow on a silicon chip accord-

ing to a preset pattern. The chip is now being

used to stimulate a nerve cell. The cell con-

ducts an electrical impulse via biological con-

tact points called synapses to another neu-

ron, whose activity, in turn, leads to a change

in the voltage at the transistor lying under it.

and some computers also operate according

to this model. But only a neurochip will en-

able researchers to observe the behavior of

an actual nerve network cell by cell.

Non-biological applications are also con-

ceivable. For example, the human brain eas-

ily performs many tasks that are difficult or

impossible for a computer. But a future mini-

brain on a chip might be able to connect

items stored in a memory bank by means of

associations. However, the process of devel-

oping such a chip may be long and difficult.

M A T E R I A L S B I O E N G I N E E R I N G

dimensional layers with perfect pore struc-

tures, even in an artificial environment.

These surfaces can have a much larger area

than that of a single bacterium, says Mertig.

They can also be mounted on solid sub-

strates such as the semiconductors and met-

als used in microelectronics. In effect, they

act as nano-scaled egg cartons, whose cavi-

ties can be used selectively to deposit metals

that are effective catalysts, such as platinum

and palladium.

The metal complexes in the cavities can

not outgrow their biomolecular cages the

bacterial pores. A regular pattern of particles

is thus created in which the particles have a

diameter of just two nanometers. This pat-

tern simultaneously emerges at millions of

locations, a key requirement for future mass

production of nanostructures. The precious-

metal particles are also situated at intervals

of just a few nanometers, meaning that their

specific surface area is vast. The larger a cata-

lysts surface, the more reactive it becomes.

Siemens plans to exploit this catalytic po-

tential to develop devices such as highly sen-

sitive gas sensors. Here, the protein mem-

brane, metal particles and all, will be

mounted on a pyrosensor, where the mini-

catalysts can then accelerate a chemical reac-

tion such as the oxidation of carbon monox-

ide. Since these clusters are more than one

order of magnitude smaller than those con-

ventionally used, chemical reactions can be

initiated even at relatively low temperatures.

The pyrosensor measures the reaction heat

that is generated and transforms it into an

electrical signal that indicates the concentra-

tion of the toxic gas.

This project is still in its infancy. The key

components the pyrosensor and the pro-

tein layers on technical carriers have been

developed, but they still need to be com-

bined. One thing that wont be a problem is

the lifetime of the biological structure in-

volved. There are indications that the pro-

teins remain stable for over a year. In any

case, they are not indispensible for the sen-

sors proper functioning. They are only a

means to an end in the production process,

says project manager Dr. Reinhard Gabl of

Siemens CT. He estimates that a finished

product will be ready in about three years.

At first glance, the growth of catalysts in

proteins doesnt seem to have much to do

with natural processes. However, this proce-

dure is based on the same principle of bio-

mineralization that applies to bone forma-

tion. In both cases, the biological template

the bacterial protein or collagen framework

guides the germ formation and the

growth of a solid inorganic mass. The differ-

ence is that in the case of the bone the inor-

ganic material is hydroxyapatite, while the

surface layers contain metal particles.

A Liver Grows in a Reactor. If artificial mate-

rials can be created by means of biological

processes, why not create new materials

identical to natural ones? Man-made bioma-

terials are, for instance, in great demand in

prosthetic devices. But this application re-

quires living cells preferably taken from the

patients themselves. Tissue engineering in

bioreactors can be used to transform the cells

into customized replacement parts (e.g.

bones, cartilage, liver tissue). These receive

all the nutrients they need to grow, and, if

necessary, a framework to attach themselves

to. The cells then grow into the desired tissue

in accordance with their respective genetic

programs.

1,800 C, leaving behind a skeleton of pure

carbon. Liquid or gaseous silicon is then

pumped into the chamber, bonding with the

carbon to form silicon carbide, an extremely

hard compound (see image below). The key

point is that the woods cellular structure is

preserved in a kind of petrified image; its

almost impossible to produce a comparably

porous ceramic material using conventional

methods. Such biomorphic ceramics could

someday be used as catalyst carriers, filters,

high-temperature insulation or construction

materials.

Bacterial Cages for Precious Metals. Wolf-

gang Pompe and his team at the Technical

University of Dresden are taking a different

approach. They are using bacterial proteins to

generate densely packed nanoclusters of pre-

cious metals for use in catalysts and sensors.

Many types of bacteria, such as Bacillus

sphaericus, have numerous uniformly sized

pores in their protein coverings, allowing ma-

terials to freely move in and out of the cell.

Its like a molecular strainer, explains

Michael Mertig, a member of Pompes team.

The researchers isolate protein molecules

and then exploit their capacity for self-organi-

zation. If chemical conditions are right, the

proteins will reorganize themselves into two-

16 P i c t u r e s o f t h e Fu t u re | S p r in g 2 0 0 3 P i c t u re s o f t h e Fu t u re | S pr i n g 2 0 0 3

The cell structure of pine wood exactly reproduced in a silicon carbide ceramic.


10/4318 P i ct u res of t he Fut u re | S pr i ng 2 00 3 P ic t ure s of t h e Fu t ure | Spr in g 2 00 3

Great Oaks

from Little Acorns

Materials with completely new properties,

quantum dots, nanotubes, microchips

that rewire themselves in short, nano-

technology is likely to be the most

promising innovation of the decade.

M A T E R I A L S N A N O T E C H N O L O G Y

Its as hard as glass and transparent. But it

isnt what it appears to be, says Dr. Wolf-

gang von Gentzkow, who heads the Center

for Functional Polymers at Siemens Corpo-

rate Technology (CT) in Erlangen, Germany.

In fact, the object is actually a type of plastic.

If you were to look at it with an electron mi-

croscope, you would be able to see small par-

ticles silicate plates that make the polymer

very hard and heat-resistant. Measuring less

than 100 nanometers across, the plates are

narrower than the wavelength of light

which makes them virtually invisible.

Welcome to the world of nanotechnol-

ogy, a place where small things, namely

nanometer-sized particles, can have a big im-

pact. A nanometer is one millionth of a mil-

limeter. Thats approximately one fifty-thou-

sandth the diameter of a hair. Too small to

bother with? Not according to Berndt Sam-

singer of Capital-Stage, a Hamburg, Ger-

many-based investment company that spe-

cializes in nanotechnology. Says Samsinger:

The impact of this new field in coming years

will be greater than that of biotechnology

and the Internet combined during the last

decade.

Market hype aside, Gentzkows particles

are relatively simple. Their layered silicates

have a structure similar to that of puff pastry

and are, for example, used in such mundane

products and processes as cat litter and paper

production. The layers can be separated with

sodium or calcium ions, and when treated

with organic ions can also be expanded in

such a manner that they detach from one an-

other when incorporated into plastics. This

results in individual, tiny silicate plates. If they

are added to a polymer at a ratio of up to five

percent, the mixture inherits the properties

of both substances. In other words, it be-

comes transparent and strong. It is also inex-

pensive to produce and can be manufactured

in large quantities. Experts predict that in

about two years the amazing material will be

mass produced and used as a plastic-coated

lens for very bright and temperature-stable

light-emitting diodes.

But the plastic from Erlangen has one big

drawback: it looks utterly unexceptional.

When you hear the word nano, which

means dwarf in Greek, you are more apt to

think of miniature submarines that prowl

through the bloodstream and annihilate can-

cer cells, or of miniature robots made of a

handful of atoms that cooperate and repro-

duce themselves as described in Michael

Crichtons new novel Prey, for example. But

thats pure science fiction, and its very

doubtful whether there will ever be applica-

tions of that sort, says Rainer Nies, who

wrote a study titled Impact of Materials at

Siemens CT in Erlangen (see p. 9). Pioneering

innovations? They will probably be the ab-

solute exception, says Nies, who studied

physics. Instead, many small innovations will

gradually appear in completely ordinary

products but the net result will probably

be just as revolutionary.

Chip Structure at the Limit. The manufac-

turers of microchips are depending on nan-

otechnology for their very survival. Moores

Law, which predicts that the number of tran-

sistors per unit area of chip will double every

18 months, will hold true until approximately

2010. But what happens when chip struc-

tures supposedly drop below 100 nanome-

Infineon researchers have deliberat

grown nanotubes on a silicon wafer

quence on left). The enlargement in

bottom left image shows an individ

nanotube. The cube (top right) cons

several hundred thousand nanotube

which are seen in close-up (bottom)

mm= millimeter, m =micrometer,nm= nanometer

Siemens researcher Dr. Wolfgang von

Gentzkow with a high-strength

transparent polymer full of nanoparticles.

The polymer could eventually serve as

a lens for light-emitting diodes.

2 mm

100 m

2 m

12 nm

ters? Thats the question that is occupying

Dr. Lothar Risch, who conducts research on

nanoelectronics at Infineon in Munich.

Rischs projects reach far into the future. He

estimates that components now being man-

ufactured in his lab as individual pieces will

not be used to produce marketable products

for at least ten years.

Risch builds field-effect transistors,

which are the smallest units of any chip.

Rischs FETs have a gate length of a mere ten

nanometers. The gate acts like a valve that

controls the electric current in a silicon chan-

nel that is only two nanometers thick. How-

ever, when the layers are that thin, the elec-

trons begin to tunnel through the gate as if

it were not even there. Rischs team there-

fore manufactured the prototype of a dou-

ble-gate transistor tilted 90 degre

which two gate electrodes sandwich t

con channel, thereby making it poss

them to control the current much m

fectively.

The next step is a quantum-dot m

module in which an insulator with a

length of 20 nanometers is placed be

the gate and the silicon channel. Less

is needed here for saving and deletin

quantum-dot memory of this kind is so

tive that even a single additional elec

the quantum dot shifts the charac

curve of the transistor noticeably. Qu

dots have made quite an impression

research community and scientists h

use them in supercomputers or in las

ultra-fast fiber-optic links.


11/43

Nano or Not? A chain of five to ten atoms amounts to approximately one nanometer a mil-

lionth of a millimeter. There is no standard definition of nanotechnology, but the most impor-

tant criterion is scale. Nanostructures are smaller than 100 nanometers. This includes thin lay-

ers that are only a few nanometers thick and take on new functions as a result. Nanotechnology

is particularly applicable to microsystems and microchips. Many properties of microsystems are

made possible by etching a silicon block (top-down approach), but in nanotechnology theres

also the bottom-up approach, whereby small building blocks (atoms, molecules, powders) are

used to manufacture larger systems, through self-organization if possible. Many properties of

nanocomponents are based on quantum effects that appear only at these tiny scales, where

the boundaries between physics, chemistry and biology become blurred. Nanoparticles are es-

pecially reactive because they have large surfaces relative to their mass. In a cube with edges

ten atoms long, almost half of the atoms are exposed to the area outside the cube. If the

edges of the cube are 1,000 atoms long, however, this is true of only 0.6 percent of the atoms.

T HE S OO T T HA T C H A NG ED T HE W OR L D

Prof. Alex Zettl has gotten his fingers dirty. Although it

looks like normal soot, the substance in his lab at the

University of California at Berkeley could change the

world, as its actually composed of tiny tubes and balls

of pure carbon. Zettls team has already used nano-

tubes (atomic model left) to make ball bearings and

electronic components.

M A T E R I A L S N A N O T E C H N O L O G Y

Two offices down from Risch is his

fiercest competitor, Dr. Wolfgang Hnlein,

who is working with carbon nanotubes.

These tubules of pure carbon have diame-

ters of between one and 30 nanometers and

lengths of up to one millimeter. They are

credited with possessing truly marvelous

properties. Depending on their structure,

they are either semiconducting like silicon,

or are capable of condu cting electrical cur-

rent a thousand times better than copper.

The tubes transport heat twice as well as di-

amonds the best thermal conductor

known. On top of that, they have 20 times

the tensile strength of steel, but are never-

theless flexible.

Everything thats possible with silicon is

also possible with nanotubes, says Hnlein.

not stored in capacitors but in miniature mag-

nets. Their polarity is reversed by a weak elec-

trical pulse, and their memory content is read

out electrically. The big benefit here is that

once stored, data bits can be retained for any

length of time. The PC memory modules used

today must be refreshed many times per sec-

ond and therefore need more power. A type

of storage that retained its memory would

also dramatically shorten the boot-up process.

His team can deliberately grow clusters of the

tubes on silicon which enables connec-

tions to be created between the layers of a

microchip. In the future, the conductors

could also consist of nanotubes, as could

diodes and transistors. And theres more: If

you place one nanotube directly on top of

another one and apply an electric field, they

bend and stick to each other until a voltage

pulse separates them again a tiny switch

that could also be used as a data storage de-

vice. Individual samples already exist in re-

search labs, but a reproducible manufactur-

ing method is still a long way off.

Nanotubes on Display. Nanotubes are ex-

pensive as much as 500 euros per gram.

But theyre likely to drop to just a few euros if,

as announced, Japanese companies begin

mass production this year. Koreas Samsung

has announced its intention to market its first

nanotube displays in 2003. Electrons can be

shot at a phosphor from the ends of the

tubes by applying an electric field as is the

case with conventional cathode ray tubes.

The difference is that the surface is totally flat

and there is no wear and tear. A nine-inch di-

agonal prototype that displays images in all

their glorious color already exists.

If transistors made of nanotubes one

day became as good as those made of sili-

con, my work would be superfluous, Risch

admits. But since no one can say for sure

whether nanotubes will make it possible to

squeeze 100 million transistors onto a chip,

he is likely to have work for years to come.

Nanotubes hold similarly untapped but

uncertain potential in other fields of re-

search. For instance, they might be used as

an admixture for particularly hard materials,

or as a hydrogen storage medium for fuel

cells. However, all such potential fields are al-

ready dominated by established technolo-gies. Whether nanotubes will be able to offer

viable alternatives is anyones guess.

At Siemens in Erlangen, Dr. Joachim

Wecker and his team are investigating mag-

netic multilayers that are only a few atomic

layers thick for use in future memory chips.

Such components are expected to hit the mar-

ket in 2004. Data bits in these MRAMs, are

Photodetector with buckyballs.

Siemens researchers use the nano-

scale soccer balls to convert light

into electricity. They are also work-

ing on an organic solar cell.


Technology

Nanopowder

Nanoscale surfaces

Nanotubes

Nanostructured chips

Nanoanalytics

Applications

Conglomerations of a few hundred atoms or

molecules that give known materials new

properties

Thin films made of a few atomic layers or

nanostructured surfaces have new properties

not seen in todays thicker layer structures

(can be used in membranes or cat alysts)

Single- or multi-wall carbon tubes with a

thickness of 1 to 30 nanometers, and withextremely high tensile strength and electrical

and thermal conductivity

Evolution of microelectronics into nanoelec-

tronics. Long-term goal is single-electron

components

Measuring and structuring

surfaces with atomic resolution

Possible Uses

Pigments for paints, cosmetics, medicines, transparent cera

with low sintering temperatures, scratch-resistant surfaces,

filled nanocapsules for self-repairing materials

Self-cleaning surfaces (Lotus Effect),

anti-reflection coatings, long-lasting implants,

scratch-resistant surfaces

Circuit conductors, transistors and diodes for memory (NRA

electron guns for flat-panel displays, reinforcement of cerammetals, plastics, hydrogen storage, nanotweezers, nanoactu

tors

Smaller memory modules and processors, magnetic data st

age, quantum dots for diodes, lasers, optoelectronics and il

nated displays

Scanning probe technology (laid the basis for

nanotechnology 20 years ago), mechanical data

storage (nano-record player)

T I N Y P AR T I CL E S W I TH D I V ER S E P R OP E RT I E S

Nevertheless, some fundamental ques-

tions remain unanswered. For instance,

Weckers team is still trying to determine if

there is a lower limit to the size of magnetic

structures. Calculations indicate that struc-

tures below 25 nanometers are not possible

because at that point ambient heat can nul-

lify the magnetization of the mini-magnets

and make stored data unreadable. Neverthe-

less, Wecker is optimistic that he will be able

to lower this value by a few nanometers.

Weckers goal is to develop components

that can be used in Siemens products. At the

circuits to accommodate new tasks.

products would profit if you could c

the hardware later on, says Wecker.

dio processor could become a video

sor, for example. Processor and m

could be combined on one chip wh

sources would adjust to fit each job.

Power for such frugal chips could

plied by the new organic solar cells t

Jens Hauch is developing at Siemens C

langen. In these cells, light is conve

electricity by a polymer semiconducto

synthetic is full of buckyballs nan

A magnetic memorya fewatomic layer

thick couldchange the worldof comput

top of the wish list, therefore, are tiny mag-

netic-field sensors for imaging processes in

medicine or for use as sensors in automo-

biles. Another project deals with reconfig-

urable logic chips in which tiny sandwich

magnets can be linked to form arbitrary logic

gates through alteration of the magnetiza-

tion direction. The millions of transistors in

todays microprocessors are hard-wired,

which means its not possible to change the

soccer balls made of 60 or 70 carbon

The cells energy yield is still a meag

percent, but Hauch is optimistic that h

will be able to manage ten percen

nanoscale power plants would not o

flexible but also much less expensive t

days silicon solar cells, which cost be

five and ten euros per watt of output.

counting on less than one euro per

says Hauch. OBernd


12/43


Considering all the hype that typically

goes hand in hand with new technolo-

gies, do you think the same could soon

happen to nanotechnology?

Smalley: I dont think that nanotechnology

is as seductive an idea as the Internet. One

of the great seductive aspects about the dot-

com era was that you could make money

without building a big infrastructure.

Nanotechnology has never been sold that

way. For me it is the art and science of

making stuff that does something on a

nanometer scale. The verb does is very

important. And you have to have stuff first.

Weve been making stuff for thousands of

years. Now its new stuff and sexier stuff but

its still stuff and you have to make it. I dont

think it reaches a level of excitement for

investors and start-up companies to the

same extent that dotcom did during the two

years of its hype. But it will be with us for a

lot longer.

Nevertheless, this is a technology with

plenty of economic potential.

Smalley:Yes, but there arent many people

who have put big money in nanotechnology.There is quite a bit of awareness at least with

venture capitalists and investors in the U.S.

that this is a place where you have to be ex-

tremely careful about investing. I dont think

there has been a great flood of money. And

the $600 million the U.S. government

invested in this area is almost entirely in

basic research. I dont think it is a large

amount at all. In fact, I think it has to be

increased dramatically from that level.

Whats a good example of what nan-

otechnology can do for us?

Smalley:One of my favorite examples is a

special continuous carbon nanotube that is a

metallic quantum wire. This material would

have the ability to transport electrical power

more efficiently than copper at one-sixth the

weight and in a vastly stronger fiber. With

that one thing if we could make it cheaply

we could implement a worldwide electrical

grid. I think this will happen and this will

transform the world.

Is that part of your research?

Smalley:Very much. For over a decade now,

my group has been devoted entirely to car-

bon nanotubes. We have been making

them, studying them and trying to learn

how we can use them practically. For most

of this time my students have been obsessed

with a particular kind of carbon nanotube

that has just a single layer of carbon like a

tiny soda straw. We are increasingly focusing

on the challenge of spinning continuousfibers of this kind, growing them very much

like a single crystal.

How long is the longest single wall nan-

otube your group has produced?

Smalley:Around a tenth of a millimeter. But

we can spin these into continuous fibers

that are many meters in length very much as

you can spin a cotton fiber. To produce

quantum wire from these nanotubes,

nanotube need not be longer than a c

of microns. The electrons hop effortles

from tube to tube. If you were to build

coil of an electric motor out of such a w

its efficiency would be much higher. T

material would have a huge impact. W

working on that. And I think it will pro

be feasible within five years.

In your opinion, what areas in mate

science will probably experience the

significant breakthroughs?

Smalley: Its very likely that within a c

of decades there will be very little met

automobiles and airplanes. We will rep

not only the body panels, but most of

structural components with crafted ne

materials that are precise down to the

atom and are largely made out of carb

trogen, oxygen and some ceramics.

What about other fields?

Smalley: Im convinced that in a coup

decades the combustion engine will d

pear. Instead, there will be fuel cells, wwill be much cheaper. Nanotechnolog

be critical for enabling this achieveme

Fuel cells will burn hydrogen that is sto

a medium that we still dont know how

make. Thats definitely going to happe

it will have a huge impact on humanit

other example is computers, and all ki

electrical devices. Moores law will alm

Richard E. Smalley, 59, shared the Nobel Prize in Chemistry in1996 for the discovery of fullerenes. A professor of chemistry

Rice University in Houston, Texas, Smalley is dedicated to the

study of carbon nano-particles.

Small Worlds Quantum Harvest

M A T E R I AI N T E R V I E W


Raw materials are about as exciting asyesterdays newspaper. As most in-vestors know, the real economic action is in

refining new and existing materials. Take the

CD, for example. Its base material, a polycar-

bonate, is worth a mere one cent. But pro-

duction is worth 100 times that, and the cost

of the final product can easily exceed 15 eu-

ros. The economic relationship between raw

materials and final products is even more

dramatic when it comes to nanotechnology,

Experts agree that the targeted manipu-

lation of materials on the atomic level will

lead to the creation of scratch-free lacquers

and glasses that repel water. It will revolu-

tionize computer technology, lasers and dis-

plays, and open up new opportunities in

medical technology (see p. 18). Nanotech-

nology will become a normal part of nearly

all industrial sectors, says Dr. Andreas Leson,

a nanotech expert at the Fraunhofer Institute

for Material and Beam Technology in Dres-

den, Germany.

But how big is the current nano market

and how much will it grow in the immediate

future? According to Deutsche Bank, pure

nanotech products such as nanopowders or

nanostructured materials currently generate

revenues of approximately $22 billion world-

wide. The biggest benefactors of this busi-

ness are chemical companies. However, be-

cause nanotechnology does not represent an

independent industry, it makes more sense

to look at the final products that are im-

pacted by it rather than at the nanoproducts

themselves, says Dr. Matthias Werner, head

of the Deutsche Bank Innovation Team.

Werner calculates that the world market

for products that contain nanocomponents,

such as computer hard disks and displays

amounts to more than $116 billion. The Ger-

man Association of Engineers, on the other

hand, pegs the figure at only 50 billion eu-

ros, with the market growing at an annual

rate of 1517 percent. This figure includes

products whose functionality is to a large ex-

tent determined by nanotechnology, such as

read heads in computer hard disks, which

alone account for revenues of some 34 bil-

lion euros. The Sal. Oppenheim investment

bank estimates that the revenue potential of

nanotech products could be 200 billion euros

in 2005. And the U.S. National Science Foun-

dation predicts that revenues from all prod-

ucts based on nanotechniques could reach

$700 billion by 2008.

M A T E R I A L S F AC T S A N D F O RE C AS T S

Despite the huge differences between

these forecasts, corporations and govern-

ments are betting on the future of nano and

the new materials that are likely to be

spawned by its molecular construction kit.

Companies from the electronics, chemi-

cal and pharmaceutical industries will profit

from this technology, says Tim Harper, CEO

of CMP Cientfica, which specializes in moni-

toring global nanotech trends.

The race to develop nanotechnologies is

leading to fierce competition among the in-

dustrialized nations. Worldwide, govern-

ments and companies spent some $4 billion

on nanotech research in 2002. The highest

levels of government subsidies for such re-

search were recorded in Japan ($650 mil-

lion), followed by the U.S. ($604 million)

and the EU (just under $325 million). How-

ever, the figure for the EU does not include

what individual countries invested. In 2001,

for instance, Germany spent $153 million on

nanotechnology subsidies more than all

other EU countries combined. Says Ger-

manys Minister of Research, Edelgard Bul-

mahn: Were serious about making nano-

technology a major priority.

OAnette Freise

Nano 101: The Economics of the 21st Century

Chemistry / materials

Energy / environmentaltechnology

Medicine / life science

Automobile manufacturing

Electronics /information technology

Functional coatings

Nanoparticles/colloides

Colored solar cells

Nanomembranes

Nanoparticlesfor tires

Antireflection coatings

New sensors (GMR)

OLED(organic light emit-

ting diodes)

CNT composites

Quantum-point solar cells

Tissue engineering

Molecular early de-tection of cancer

Switchable lacquer paints

Molecular electronics

Spintronics

Magnetic fluids

Carbon nanotubes (CNT)

Targeted transportof active ingredients

Nanostructuredhydrogen storage units

Lab-on-a-chip systems,biochip arrays

Interference lacquer

Nanoscalable composites

Nanotubedisplays

Millipedehard disks

MRAM/FRAM-memory

Market readiness already achieved

Market development Prototypes Basic research

Market readiness in 0 5 years Market readiness in 5 10 years Market readiness in 10 15 years

N A NO T EC H NO L OG Y D E VE L OP M EN T T R EN DS A N D F I EL D S O F A P PL I C AT I ON

Source:VDIGermanAssociation

ofEngineers(2002)


13/43

What s your definition of nanotechnology?

Kroto: Molecules that do things.

Thats it?

Kroto: Well, Im thinking of molecules with

functions. You see, the real advances are in

neuroscience and the application of nano-

technology to produce molecules that have

interesting properties. Key molecules such as

haemoglobin illustrate the sorts of things we

might be able to make in the future.

What exc

The magazine for reseach and innofation (Spring 2003

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