A material repairs itself multiple times.
A new polymer material that fixes its own cracks could be a step toward self-healing medical implants or self-repairing materials for use in airplanes and spacecraft. It consists of an epoxy polymer layer containing tiny catalyst particles, deposited on a substrate containing microchannels filled with a liquid.
When a crack in the polymer layer spreads to the microchannels, the liquid flows out and comes in contact with the catalyst, says Nancy Sottos, a professor of materials science and engineering at the University of Illinois at Urbana-Champaign and one of the researchers who led the work. Ten hours later, the liquid solidifies into a polymer.
Researchers have previously made self-healing plastics, but this is the first time anyone has made a material that can repair itself multiple times on its own. The material survived up to seven cracks before the catalyst stopped working.
“It’s essentially like giving life to a plastic,” says Chris Bielawski, a chemistry professor at the University of Texas at Austin. “This is an amazing proof of concept.”