https://phys.org/news/2018-10-transparent-flexible-material-silk-nanotubes.html

"Silk is a very interesting material. It is made of natural fibers that humans have been using for thousands of years to make high 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."

As explained by the authors in the video below, these regenerated silk fibroins (RSFs) however typically are chemically unstable in water and suffer from inferior mechanical properties, owing to the difficulty in precisely controlling the molecular structure of the fibroin proteins in RSF films. Bedewy and his NanoProduct Lab group, which also work extensively on carbon nanotubes (CNTs), thought that perhaps the molecular interactions between nanotubes and fibroins could enable "tuning" the structure of RSF proteins.