Flexing Synthesized Biceps

Corinna Wu at MIT's Technology Review reports on a discovery made by researchers at the University of British Columbia in Canada that could be the key to the development of an artificial biomaterial that mimics the elasticity of human muscle. The results of the study are reported in Nature. The difficulty in developing such a biomaterial, says Wu, is that it's hard to create anything that can take large amounts of strain and still change shape. But the material synthesized by the UBC researchers achieves the elasticity of muscle by mimicking the microscopic structure of the muscle protein titin, she adds. "The structure of titin resembles a string with beads — globules of folded protein sequences are connected by floppy, unstructured sequences," Wu says. "Hongbin Li, a chemist at the UBC, and his colleagues … chose a mechanically stable protein sequence that folds in on itself to form globules, and another protein called resilin to serve as the floppy connectors." They call the result "mini-titin," a structure which resembles titin, though on a smaller scale. They then chemically linked the protein strands together to form a hydrogel and found that it behaved like real muscle, Wu says. Artificial muscles could one day be used to repair muscle damage and even to control robots without using motors, she adds.