Super-tough, super-stretchy artificial spider silk spun from water
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Researchers from the University of Cambridge have developed a new tough and super-stretchy material that is 98 per cent water.
Spider silk is among the strongest materials in nature, boasting a range of useful properties. Consequently, it is a popular subject of study for researchers hoping to create synthetic versions of the fibre, which could be used in laboratory instruments and consumer technology.
While some attempts to create artificial spider silk have been successful, these methods typically require the use of solvents and high temperatures, and lack the strength – or other properties – of natural silk.
“We have yet to fully recreate the elegance with which spiders spin silk,” said Dr Darshil Shah of the University of Cambridge’s Department of Architecture.
Dr Shah and his colleagues at Cambridge – a collaboration of architects and chemists – set about creating their own artificial spider silk by “spinning” fibres from hydrogel: a material which is 98 per cent water and 2 per cent silica and cellulose. These are naturally occurring materials, held together in a network of molecular bridges and cucurbiturils.
The chemical interactions between these components allow for long, thin fibres to be extracted from the gel, just a millionth of a metre in diameter. After approximately 30 seconds, the water evaporates, leaving a strong, super-stretchy fibre.
These fibres are stronger than artificial silks, viscose, and mammalian hair. They resemble tiny bungee cords, being capable of absorbing large amounts of energy, much like natural spider silk.
“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 Shah. “However, our fibres are non-toxic and far less energy-intensive to make.”
The sustainable approach to creating the fibres is a cause for celebration for the researchers; unlike other methods for creating artificial spider silk, this method can be carried out at room temperature, and is entirely non-toxic. The researchers hope that their technique could be adapted to improve the manufacture of other synthetic fibres, which often have high energy requirements, and are toxic.
“We think that this method of making fibres could be a sustainable alternative to current manufacturing methods,” he concluded.
The researchers hope that their material could be used in textiles, sensors and other materials.