Shape of things to comeSelf-healing plastic demonstrated
University of Illionis researchers show material that can repair itself multiple times without any external intervention
Self-healing plastic: More and more items and gear used by soidliers and first responders are made of plastics. It is good news, then, that researchers at the University of Illinois at Urbana-Champaign (UIUC) have made a polymer material that can heal itself repeatedly when it cracks. It should be considered as a very important step toward self-healing medical implants and self-repairing materials for use in airplanes and spacecraft and on the battlefield. It may also be used for cooling microprocessors and electronic circuits, and may show the way toward plastic coatings that regenerate themselves.
Fighting Illini researchers have reported of advances with self-healing materials already six years ago, but Technology Review’s Prachi Patel-Predd reports this is the first time anyone has made a material that can repair itself multiple times without any external intervention, says Nancy Sottos, materials-science and engineering professor at UIUC and one of the researchers who led the work. “It’s essentially like giving life to a plastic,” says Chris Bielawski, a chemistry professor at the University of Texas at Austin. The ultimate goal would be to create materials that mend themselves, he says, and “this is an amazing proof of concept.”
Sottos and her colleagues have designed the new material, reported in this week’s Nature Materials (sub. req.) to mimic human skin. We know from our own experiences that if the skin’s outer protective layer is cut, the inner layer, which is infused with a dense network of tiny blood vessels, transports nutrients to the cut to help with healing. The self-healing material consists of an epoxy polymer layer deposited on a substrate that contains a three-dimensional network of microchannels. The epoxy coating contains tiny catalyst particles, while the channels in the substrate are filled with a liquid healing agent.
Practical self-healing materials may be a few year away, but the day of using them in prosthetics and medical implants made from biocompatible self-healing materials can already be imagined. Initially the cost of these materials may be on the high side, but in the future, different chemistries could lead to cheaper self-healing materials, says Bielawski. “You could use cheap epoxies … that you can buy at Home Depot … as a healing agent,” he says.
