Draper Prize Program 4-24-12

7/28/2019 Draper Prize Program 4-24-12

1/10

Reflectionsof Dr. Martin SchaDt

Upon the occasion of his 2012 Draper Prize LectureApril 24, Boston Museum of Science & Cambridge Science Festival


2/10

I grew up in a small country

village in the northern part o

Switzerland where, in the 1940s

and 50s, no one ever thought

o going to university, including

mysel, even though I made many

daring physical and chemical

experiments. Admittedly, some

experiments were not appreciated

by our neighbors, especially

when they interered with

radio reception or were o noisy

pyrotechnical nature!

Since I did not have a camera

when I was young, I have no

pictures o my early experiments.

Today I regret this because some

o my early electronic tube radios

and transmitters looked quite

interesting, aintly resembling

haystacks. I made my experiments essentially with bits and pieces rom scrap radios (the

unit price o a scrap radio was $5, which was a small ortune at the time). Precautions

to saeguard the operator rom electrical shocks were not considered. Later, havingearned some money during my apprenticeship, I was able to build more sophisticated

transmitters and even buy a small Hallicraters short-wave radio.

Since university was not an obvious

alternative, I began a our-year

apprenticeship as an electrician in

Basel, the oldest university town in

Switzerland (ounded 1460). I very

quickly realized that I wanted to learnmore about science, so I caught up on

studies at evening school and passed

Dr. Martin Schadt

Physicist and Inventor 2012 Draper Prize Recipient

Dr. Martin Schadt in his Roche Lab in 1988.

One of Schadts (illegal) short-waveradio stations (1954).


3/10

my entrance exams or university. Having a keen interest in experiments, I was especially

ascinated by physics and its technological implications.

While pursuing my masters degree in experimental physics, I became interested in

organic semiconductors, quite an exotic topic at the time. I liked the interdisciplinary

research approach and the reedom to design and prepare my own experiments and

equipment. Few groups world-wide were doing research on organic semiconductors, and

the only regular lecture on solid-state physics at the University was oered by my thesis

advisor, Proessor E. Baldinger. He was an outstanding teacher in solid-state electronics,

both encouraging and supporting unconventional research projects.

Ater completing my thesis in 1967, I

was granted a two-year postdoctoral

ellowship at the National Research

Council (CNRC), Ottawa, Canada. In the

group o D. F. Williams, I continued my

research on electronic charge-transport

and related optical properties in molecular

crystals. Because o the inecient

charge carrier injection into organic

crystals a prerequisite or electron-hole

recombination and generation o lightemission I developed more ecient

hole-injecting electrodes. These new

Now, as so oten happens

in physics, new surprising

ndings were made! Contrary

to initial thought, I could show

ater numerous experiments

that it was not necessary

or the electric eld to ullyunwind the liquid crystal helix.

Schadts rst TN-LCD prototype made in 1971 to convince the Roche

Board of Directors of the operability of the Twisted Nematic (TN)-Effect.


4/10

solid-state electrodes permitted electrically

insulating organic materials to be converted

into considerably ecient light-emitting organic

semiconductors. This paved the way or newoptical and electronic experiments.

One problem was that the electrodes were highly

sensitive to residual water, which limited their

lietime to seconds in an ordinary lab atmosphere.

Ater having remedied this problem, I successully

developed the rst solid-state organic light

emitting display (OLED), which led to my rst

U.S. patent. Due to the 1mm-thick anthracenesingle crystal that I used, more than 100V were

required to generate sucient light output rom

the display. This voltage was much too high or

semiconductor drivers.

My two-year ellowship ended at this stage.

Discouraged by the large gap between the

perormance o my simple OLED prototype and

industrial targets, I elt pessimistic about the

uture o organic semiconductors and decided to

switch elds. In act, it wasnt until 25 years later,

ater chemical vapor deposition (CVD) had been

developed, that C.W. Tang and S.A. VanSlyke at

Kodak demonstrated that ecient low voltage

operation o OLEDs was possible by using very

thin (


5/10

Wolgang Helrich, who had

let RCA to join the Roche

liquid crystal group. Inspired

by a polarization observa-tion made by the French

crystallographer Mauguin in

1911, Helrich had the idea

that the long axes o ini-

tially twisted nematic liquid

crystal molecules between

crossed polarizers could be

switched by an electric eld

perpendicularly, causing anoptical change.

Contrary to the lack o

interest shown by RCA

management towards this

idea, I was immediately

attracted and began to design and perorm a series o electro-optical experiments

or investigating its easibility. In the late all o 1970, I was able, or the rst time, to

reproducibly switch and observe polarization changes in a twisted nematic LC-congurationunder the microscope. Now, as so oten happens in physics, new surprising ndings were

made! Contrary to initial thought, I could show ater numerous experiments that it was

not necessary or the electric eld to ully unwind the liquid crystal helix, i.e. to switch the

long molecular LC-axes vertical to the cell substrates. To my own astonishment, I ound

that a ew volts were sucient to block light transmission. This was a more than 20-

times lower voltage than we had initially expected to be required or complete vertical LC-

Dr. Martin

Schadt in

his Roche

Lab in 1979.

First page of the Swiss TN-LCD patent of Helfrich and Schadt,led Dec. 4, 1970.


6/10

alignment. The experiments showed that it is enough or the electric eld to deorm only

the central part o the TN-helix to achieve an electro-optical eect. We patented the

new eect on December 4, 1970, which became known as twisted nematic (TN)-eect,

and published the surprising results. A theory describing the electro-optics o twisted

nematic LC-congurations did not exist at the time. It was only developed three years

later by Dwight Berreman at Bell Labs, NJ. In the same year, Peter Brody realized the

rst thin-lm transistor (TFT)-addressedTN-LCD.

With the exception o two years

o research in biophysics due to

interruption o liquid crystal research

by Roche in 1971 my R&D activities

ocused on the development o

electro-optical eld-eects or liquid

crystal displays and new, industriallyviable liquid crystal materials. The

TN-invention was licensed world-

wide by Roche to the emerging liquid

crystal (LCD)-industry. TN-LCDs

initiated a paradigm change rom

dynamic scattering displays towards

todays fat panel eld-eect liquid

crystal display industry. I supported

this development with my teamby advancing the experimental

techniques or determining all relevant

LC-material properties, searching

or correlations among molecular

Drs. Schadt and Helfrich received the

Munich and Aachen Prize for Technology

and Natural Sciences for invention of the

TN-LCD, Berlin, 1994.

First page

of the TN-

LCD patent

granted in

Japan (which

looks very

picturesque).


7/10

structures, display perormance, and materialproperties. As a result, the pharmaceutical

company, Roche, established itsel as a major

liquid crystal supplier or the emerging LCD-

industry. Moreover, I invented the linear

photo-polymerization technology with my

collaborators in 1991, enabling alignment and

optical patterning o monomer and polymer

liquid crystals on suraces by light rather than

mechanically. The technique opened up novelLCD operating modes with broad elds o

view and short response times. New optical

polymer thin-lm applications became easible.

Examples include high resolution patterned

A Polarization Microscope picture of one ofSchadts rst TN-LCD experiments made at

Roche in the fall of 1970 which virtually failed.

The picture looks like a work of art rather than

an element of a TN-LCD. Some of the black

parts in the picture, however, showed signs of

an electro-optical effect; i.e. optical switching

upon voltage application.

optical retarders or 3D-LCDs,

polarization sensitive optical

security elements, and optically

anisotropic integrated opticsdevices, among others.

I headed the Liquid Crystal Re-

search Division o Roche until

1994. Based on the photo-align-

ment technology, my Division was

spun out as the company ROLIC

Ltd, an interdisciplinary Research

and Development Companywhich I headed as its rst CEO

and delegate o the Board o Di-

rectors until my retirement rom

the operating business in 2002.

Since then, I have been active

as an independent inventor and

scientic advisor to research

organisations and industry. I

am a Fellow o the Society o

Inormation Display and o the

European Academy o Sciences,

holding more than 106 U.S.

patents. I have published 182

papers in leading scientic

journals. Among other awards, I

am the recipient o the IEEE Jun-

Ichi-Nishizawa Medal and the2012 Draper Prize.

In my Draper Prize Lecture at the

Museum o Science, Boston, in

April 2012, I presented the his-

torical development o todays

eld-eect LCD and LC-mate-

rial technologies as well as the

world-wide interdisciplinary con-tributions o physicists, engineers

and chemists to the successul

story o fat panel displays.


8/10

Electro-optical Response of Lipid Membranes

Because Roche as a pharmaceutical company was interested in cell mechanisms/

interactions and because I had decided to stay with the company ater Roche

stopped nematic LCD R&D in 1971, I started looking or interesting problems in

the eld o articial molecular bilayer membranes (black lipid lms).

Since atty acids exhibit liquid crystalline properties, this enabled combining my

interests in electronic transport phenomena and electro-optical eects with bio-

physics. Lyotropic LCs (atty acids) are essential components o our cell mem-

branes. Without their liquid crystalline long range order, blood cell membranes,

or instance, could not exist.

When I started reading biophysics literature to get ideas or experiments, I came

across a publication by an MIT proessor who had investigated the electro-optical

response o lipid bilayer membranes doped with vitamin A acid. He explained hisresults with a semiconductor band model. As a solid-state physicist, this puzzled

me because an important prerequisite or band models is a periodic lattice made

up o a very large number o atoms/molecules in transport direction. Because bi-

layer membranes consist o just 2 molecules in transport direction, I did not under-

stand his results and conclusions. Thereore, I decided to repeat his experiments.

Ater several months o hard work and struggling with tricky experimental condi-

tions, I discovered that he was indeed wrong. He had not measured cell mem-

brane eects but the optical response o his electrolyte/electrode combination.

I developed an electronic analogy model o the photo-response o lipid bilayermembranes doped with Vitamin A, which properly explained the experiments, and

was lucky to publish my rst work in biophysics research in a renowned journal:

M. Schadt. Photoresponse o bimolecular lipid membranes pigmented with retinal

and vitamin A acid, Biochimica and Biophysica Acta, Vol.323, 351-366, 1973.

The Effects of Neurotransmitters on Electrical Brain Response

Based on my earlier PhD work on charge carrier transport in molecular crystals

and rom a comment o a chemist riend who mentioned that Roche manuac-

tured ionophores (molecules which transport ions across cell membranes) in the

U.S. to prevent chickens in large arms rom catching a deadly disease, I thought

Ventures into Biophysics Research


9/10

this topic would be interesting. Wondering whether I could dope my

membranes with this ionophore to nd out which type o ions were re-

sponsible or the chicken eect, I discovered interesting correlations.

And I was just about to write up the results or publication when I met

a neurologist in the medical research department o Roche who used

the same ionophore to extend the lie o his dogs in his studies o theeects o neurotransmitters on electrical brain response. I wondered

whether the ion selectivity ound in my membranes would correlate

with neurotransmitter transport and started to extend my experi-

ments to neurotransmitters. The results were very interesting indeed.

I ound that not only ion transport was selective, but that neurotrans-

mitter transport across ionophore-doped membranes was selective

as well. The next step was to investigate whether the specic neu-

rotransmitters which my colleague ound most ecient in his dogswould also be most ecient in my experiments, which was the case.

This was an exciting result because it showed that experiments with

simple bimolecular membranes can correlate with the mechanisms in

complex living cell membranes. We published the results in:

M. Schadt and G. Husler, Permeability o lipid bilayer membranes to

biogenic amines and cations: Changes induced by ionophores and cor-

relations with biological acitivites, Journal of Membrane Biology, Vol.

18, 277-294, 1974.

And, What If?

At this stage o my short but very interesting biophysics R&D time,

and because Seiko Epson had approached Roche in the meantime to

license the twisted nematic (TN)-LCD patent rights, Roche suggested

that I restart interdisciplinary LCD- and LC-material research which

had been stopped in 1971. Apart rom its world-wide TN-licensing

activities, Roche became a major LC-material supplier or the emerg-ing LCD industry.

Sometimes I wonder what would have happened i I had continued

working in biophysics; well, unortunately one lives only once.


10/10

The Draper Prize was instituted by

the National Academy of Engineering

in 1988 at the request of Draper

Laboratory to honor Dr. Charles Stark

Draper and increase public awareness

of the contributions of engineering to

society. The prize is awarded annually

for innovative engineering achievementsand their reduction to practice in ways

that ultimately have improved the well-

being and freedom of humanity.

For more information, visit

www.draperprize.org.

www.draper.com#*

Documents

Draper Prize Program 4-24-12