Researchers from University of Cambridge, UK, including one of Indian origin, have designed a super strong, stretchy artificial spider silk, composed almost entirely of water. The fibres, which resemble miniature bungee cords as they can absorb large amounts of energy, are sustainable, non-toxic and can be made at room temperature, and it may be used to make eco-friendly textiles and sensors.

The fibres are spun from a soupy material called a hydrogel, which is 98 per cent water. The remaining 2 per cent of the hydrogel is made of silica and cellulose, both naturally available materials, held together in a network by barrel-shaped molecular "handcuffs" known as cucurbiturils. The chemical interactions between different components enable long fibres to be pulled from the gel.

The fibres are pulled from the hydrogel, forming long, extremely thin threads a few millionths of a metre in diameter. After roughly 30 seconds, the water evaporates, leaving a fibre which is both strong and stretchy. Darshil Shah, from Cambridge says although their 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.

The fibres are capable of self-assembly at room temperature, and are held together by supramolecular host- guest chemistry, which relies on forces other than covalent bonds, where atoms share electrons. They think that this method of making fibres could be a sustainable alternative to current manufacturing methods, added Shah.

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 few synthetic fibres which have this capacity but high damping is one of the special characteristics of spider silk.