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more tear-resistant than steel. The researchers of HITS have – together with colleagues from Shanghai and Stuttgart – published new findings in the Biophysical Journal.

“The article is the result of an interdisciplinary project,” says Dr. Frauke Graeter. “We have linked physical modeling of biological problems with engi- neering techniques.” Besides the scientists of HITS, also Dr.-Ing. Bernd Markert (Institute of Mechanics, University of Stuttgart) and researchers of the CAS- MPG Partner Institute of Computational Biology Shanghai have been involved in the project.

Exact physical models can only be computed for very small fragments of silk fiber by today‘s com- puter technique. Even for supercomputers it takes months to compute single components. “We use the results of our own calculations and scale them up to the whole silk fiber, similar to an extrapola- tion,” explains Frauke Gräter. “To this end we use methods and techniques of engineers, which are for example used by crash tests.” Thus, the HITS-sci- entists can explore with their computer simulations how the whole silk fiber is responsive to mechanical force, if it is pulled for example.

The results of the study show, how the main com- ponent of the silk protein has to be arranged to achieve optimal breaking strength and elasticity. “The main components are on the one hand crystal- line, thus very ordered, assemblies and on the other hand soft, disordered units,” says Frauke Gräter.

Up to now, it was presumed that those two compo- nents of silk are arranged by accident. The scien- tists from Heidelberg have shown now, that silk is

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only really tear-resistant, if these components are arranged in continuous slices – “like filmy slices of salami,” says Frauke Gräter.

Up to now, there is no synthetic material which can compete with silk. “Our computer schemes can help polymer chemists to develop new materials which are both tear-resistant and elastic”, Frauke Graeter sums up.

Murat Cetinkaya, Senbo Xiao, Bernd Markert, Wolfram Stacklies and Frauke Graeter: Silk Fiber Mechanics from Multiscale Force Distribution Analysis, In: Biophysical Journal, Volume 100(2011), Issue 5, 1298-1305, 2 Mar- ch 2, 2011, DOI:10.1016/j.bpj.2010.12.3712: http://dx.doi.org/10.1016/j.bpj.2010.12.3712

Researchers at National Tsing Uha University had found a way to use silk membranes in flexible electronic devices. http://www.pcworld.com/article/221346/taiwan_re- searchers_turn_to_silk_for_flexible_edevices.html

Stanford researchers have developed an ultrasen- sitive, highly flexible, electronic sensor that can feel a touch as light as an alighting fly. Manufac- tured in large sheets, the sensors could be used in artificial electronic skin for prosthetic limbs, robots, touch-screen displays, automobile safety and a ran- ge of medical applications.

By sandwiching a precisely molded, highly elastic rubber layer between two parallel electrodes, the