Applications stretch out for insect elastic

Scientists in Australia have synthesised a polymer based on the elastic protein resilin used to keep flies flying, fleas jumping and cicadas singing. The stretchy polymer has numerous potential applications across medicine and industry, the researchers claim.

Resilin can work time and again without wearing out, allowing flies to flap their wings up to 200 times a second. Flies can do this because of resilin’s high resilience - the ability to recover from deformation - and its long fatigue lifetime - the number of times it can be deformed without failing.

Christopher Elvin from CSIRO Livestock Industries, Brisbane, and colleagues cloned a fruit fly gene that encodes resilin, and used bacteria to express a recombinant, soluble form of the protein. 

Elvin developed a photochemical crosslinking method to mimic the tyrosine crosslinks in natural resilin. This turned the soluble recombinant pro-resilin protein into a high molecular weight polymer, which had better resilience than the best synthetic high-resilient rubber currently available. 

In nature, resilin’s tyrosine crosslinks can best be seen in dragonfly tendons, which contain resilin similar to that in fruit flies, says Elvin. He compared his synthetic version to dragonfly resilin. ’We find the same level of crosslinking in this material as is found in native resilin from dragonfly tendons,’ Elvin told Chemistry World. 

Resilin’s ability to bounce back can be exploited in the synthetic version, said Elvin. Applications could range from spinal disc implants and heart and blood valve substitutes to high-efficiency industrial rubbers, microactuators and nanosprings. Katharine Sanderson