Protein Fibers Can Become Electrical Wiring

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Protein Fibers Can Become Electrical Wiring

http://medicalnewscenter.com/out/out.cgi?

http://www.sciencedaily.com/releases/2008/11/081125113322.htm

Researchers at Linköping University in Sweden have succeeded in

creating electrical wires consisting of protein fibers encased in

plastic. The 10 nanometer thin fibers are self-organizing and

compatible with biological systems.

" For the first time, we have created proteins that conduct current

extremely well but can also function as semiconductors in

transistors, for example, " says Mahiar Hamedi, who developed the

technique together with Herland and associates at the Division

for Biomolecular and Organic Electronics. The technology is described

in his doctoral dissertation.

Last year Mahiar Hamedi made headlines with his invention of

conductive textile fibers, which can be used to produce electronic

cloth. Now he has scaled down that technology by a factor of about a

thousand.

These nano fibers are produced in ordinary test tubes. One component

is amyloid fibers, long, stable protein fibers that occur naturally

in living organisms and can cause, among other things, nerve

disorders in humans and animals. The other component is a conjugated

polymer (PEDOT-S), a plastic material that conducts current. When the

two are mixed in water, the plastic attaches to the fibers and forms

a conductive shell that is merely a handful of atoms thick.

" The beauty of the self-assembly process is the ease under which

PEDOT-S binds onto the amyloid fibrils directly in water without the

need of any heat, and in a matter of a few minutes " Hamedi writes in

his dissertation.

By providing the fibers with charged outgrowths, it is possible to

get the molecules themselves to form desired structures. This can be

an inexpensive and effective way to create extremely tiny three-

dimensional electronic circuits.

Using their nano fibers as a channeling material, Mahiar Hamedi and

his associates have constructed fully functional electrochemical

transistors that work in the area of 0-0.5 volts.

The dissertation also describes a method for creating nano patterns

in conductive plastic. As organic material is beginning to be used in

more and more advanced electronic circuits, there is a need to fit a

huge number of components in a tiny area. The solution is to form the

plastic in a mold with structures that are smaller than the

wavelength of visible light - and therefore invisible!

The dissertation Organic electronics on micro and nano fibers - from

e-textiles to biomolecular nanoelectronics was publicly defended

November 21, 2008. External examiner was Malliaras, Cornell

University, USA.