A team of architects and chemists from the University of Cambridge have created a super stretchy, strong and sustainable artificial spider silk.
Spider silk is one of nature’s strongest materials, and scientists have long been attempting to mimic its properties for a range of applications, with varying degrees of success.
Described as a “miniature bungee cord” because of its ability to absorb large amounts of energy, the new artificial spider silk is ‘spun’ from a material that is 98% water and could be used to make textiles and sensors.
The technique used to create the new silk improves upon earlier methods of making synthetic spider silk because it doesn’t require high-energy procedures or extensive use of harmful solvents, and it could substantially improve methods of making synthetic fibres of all kinds, since other types of synthetic fibres do rely on high-energy, toxic methods.
“Although our fibres are not as strong as the strongest spider silks, they can support stresses in the range of 100 to 150 megapascals, which is similar to other synthetic and natural silks,” said Dr Darshil Shah from Cambridge’s Department of Architecture.
“However, our fibres are non-toxic and far less energy-intensive to make.”
The fibres designed by the Cambridge team are “spun” from a material constructed from naturally available materials called hydrogel, which is 98% water and 2% silica and cellulose.
By combining the different components, the scientists are able to pull long spider silk-like fibres from the gel.
After roughly 30 seconds, the water evaporates, leaving extremely thin threads behind – a few millionths of a metre in diameter – which are both strong and stretchy.
The strength of the fibres exceeds that of other synthetic fibres, such as cellulose-based viscose and artificial silks, as well as natural fibres such as human or animal hair.
In addition to its strength, the fibres also show very high damping capacity, meaning that they can absorb large amounts of energy, similar to a bungee cord.
There are very few synthetic fibres which have this capacity, but high damping is one of the special characteristics of spider silk. The researchers found that the damping capacity in some cases even exceeded that of natural silks.
“We think that this method of making fibres could be a sustainable alternative to current manufacturing methods,” said Shah. The researchers plan to explore the chemistry of the fibres further, including making yarns and braided fibres.