A new examination of silkworm cocoons suggests how they could inspire lightweight armour and environmentally-friendly car panels.
Scientists from Oxford University’s Department of Zoology studied 25 types of cocoons for clues to how the structures manage to be very tough but also light and able to ‘breathe’.
Fujia Chen, David Porter, and Fritz Vollrath report in Journal of the Royal Society Interface on their research into the factors that enable cocoons to protect their occupants.
‘Cocoons protect silkworms in the wild as firstly a hard shell, secondly a microbe filter and thirdly as a climate chamber,’ Fritz tells me, adding that this order of importance will change depending on the threats and environmental conditions faced by each species.
The lightness of cocoons is down to both the material they are made of – silk – and the way that this is turned into a layered composite material with a clever arrangement of silk loops that are woven together with gum only at the intersections.‘By controlling the density of the 'weave' the animal controls the material properties of each layer, and by having different properties for different layers the animal can make tough yet light structures,’ Fritz explains.