Researchers at Tsinghua University in China have shown that feeding silkworms mulberry leaves sprayed with an aqueous solution containing a 0.2% (by weight) graphene or carbon nanotubes can result in reinforced silk that could be used in applications like durable protective fabrics, biodegradable medical implants, and wearable electronics.
This carbon-enhanced silk is said to be twice as tough as regular silks, and can withstand at least 50% higher stress before breaking. The team heated the silk fibers at 1,050 °C to carbonize the silk protein and then studied their conductivity and structure. The modified silks conduct electricity, unlike regular silk. Raman spectroscopy and electron microscopy imaging showed that the carbon-enhanced silk fibers had a more ordered crystal structure due to the incorporated nanomaterials.