Researchers produced super-strong silk feeding carbon nanotubes to silkworms
Researchers now report a clever way to make the gossamer threads even stronger and tougher: by feeding silkworms graphene or single-walled carbon nanotubes. The reinforced silk produced by the silkworms could be used in applications such as durable protective fabrics, biodegradable medical implants, and eco-friendly wearable electronics, they say.
In contrast to regular silk, the carbon-enhanced silks are twice as tough and can withstand at least 50% higher stress before breaking. The team heated the silk fibres at 1,050 °C to carbonise 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 fibres had a more ordered crystal structure due to the incorporated nanomaterials. The electrical conductivity of the carbon-reinforced silk might make it suitable for sensors embedded in smart textiles and to read nerve signals
To make carbon-reinforced silk, Yingying Zhang and her colleagues at Tsinghua University fed the worms mulberry leaves sprayed with aqueous solutions containing 0.2% by weight of either carbon nanotubes or graphene and then collected the silk after the worms spun their cocoons, as is done in standard silk production.