Scientists have long known about the strength, resilience and elasticity of spider silk, which has properties far superior to even cutting-edge synthetic fibres like Kevlar. But scientists didn’t realise until recently that 400 million years of evolution have allowed these scary little creatures to develop silk with built-in shape memory, i.e. it can regain its initial configuration without any external stimulus. This discovery was made by Olivier Emile and Albert Le Floch of the French University of Rennes’ Laser Physics Laboratory and their colleague Fritz Vollrath in Oxford (reported in Nature, 30 March 2006).
When reconstructing Beth’s 1936 Princeton kinetic experiments, using light to turn a blade, the Rennes/Oxford team noticed that the thread from which the blade was hanging – spider silk – didn’t behave like other threads. So they went out into the lab garden and down to the cellar to capture specimens of Areneus Diadematus (garden spider) and Pholcus (daddy-long-legs spider), and even took a trip to the Besançon insectarium to obtain specimens of the Madagascan Nephilas (giant orb-weaving spider), to take a close look at the exceptional qualities of their silk. Olivier Emile believes that the silk’s torsional properties could be used to develop twist-free climbing ropes for mountaineers. And because spider silk is made of protein built from amino acids, torsion experiments could unlock the secrets of protein folding mechanisms and give rise to a wide range of applications, even going so far as the treatment of prion diseases such as Bovine Spongiform Encephalopathy, the dreaded mad cow disease. It may be an untangled web we weave…