Self-healing materials take cue from nature

BBC : Self-healing materials—whether metal, plastic, or a carbon composite—have been around for almost a decade. Now Nancy Sottos and coworkers at the University of Illinois at Urbana-Champaign have developed a new, nature-inspired technique, which they describe in the Journal of the Royal Society Interface. It involves impregnating plastic with a fine network of channels, each less than 10 ^-8 meter in diameter, which can be filled with liquid resin, writes Leila Battison for the BBC. The microvascular networks spread out in the material to function much like an animal’s circulatory system, supplying the healing agent to all areas. Syringes on the outside of the material put the liquid resin under constant pressure so that when a crack appears, the pressure drives the fluid into it. Materials that could repair themselves as they crack would have many uses, including in civil engineering.