Silkworm cocoon inspires new technology for lightweight armour and cars.
About 500 million kilograms of raw silk is produced for the global market each year, according to the researchers in an Oxford University press release. Although most of this is boiled down and unraveled for textiles, researchers from Oxford University believe silkworm cocoon properties could inspire advanced materials for use in technologies such as car panels, protective helmets and light-weight armour.
Researchers David Porter, Fujia Chen and Fritz Vollrath examined the structure of silkworm cocoons to find clues as to how the structures manage to be so tough, but also light and able to “˜breathe’. They reveal in the paper published in the Journal of the Royal Society Interface that these advances in materials could transform industries struggling with the rising cost and scarcity of raw materials, especially those in developing nations such as China and India.
Silkworm cocoons have evolved a wide range of different structures and combinations of physical and chemical properties in order to cope with different threats and environmental conditions. They protect silkworms as firstly a hard shell, secondly a microbe filter and thirdly as a climate chamber. Researchers note that the structure and morphology of the cocoons are far more important than the material properties of the silk fibres themselves.
“By controlling the density of the “˜weave,’ the animal controls the material properties of each layer, and by having different properties for each layers the animal can make tough yet light structures,” Vollrath says.
Given the vast availability of silkworm cocoons and the virtually carbon neutral production process, the utilisation of the cocoons for technologies such as car panels would be totally sustainable. The next stage of the scientist’s research is to find a way to replicate the structures found in cocoons or use them as a base material impregnated with gels as a way of developing a scalable production process.
“Silk cocoons are fully sustainable, non-perishable and climate-smart agricultural products,” Vollrath says. “They are also very light, tough composites. Using cocoons as base materials, in combination with equally sustainable fillers should help us make sustainable composites with many layers of complexity.”
Source: University of Oxford