Making a transparent flexible material of silk and nanotubes

The silk fibers produced by Bombyx mori, the domestic silkworm, has been prized for millennia as a strong yet lightweight and luxurious material. Although synthetic polymers like nylon and polyester are less costly, they do not compare to silk's natural qualities and mechanical properties. And according to research from the University of Pittsburgh's Swanson School of Engineering, silk combined with carbon nanotubes may lead to a new generation of biomedical devices and so-called transient, biodegradable electronics.

The study, "Promoting Helix-Rich Structure in Silk Fibroin Films through Molecular Interactions with Carbon Nanotubes and Selective Heating for Transparent Biodegradable Devices", was featured on the Oct. 26 cover of the American Chemistry Society journal AppliedNano Materials.

"Silk is a very interesting material. It is made of natural fibers that humans have been using for thousands of years tomakehigh quality textiles, but we as engineers have recently started to appreciate silk's potential for many emerging applications such as flexible bioelectronics due to its unique biocompatibility, biodegradability and mechanical flexibility," noted Mostafa Bedewy, assistant professor of industrial engineering at the Swanson School and lead author of the paper. "The issue is that if we want to use silk for such applications, we don't want it to be in the form of fibers. Rather, we want to regenerate silk proteins, called fibroins, in the form of films that exhibit desired optical, mechanical and chemical properties."