The South Korean electronics manufacturer LG has officially unveiled its new G Flex phone, and it boasts a promising new feature: a “self-healing” coating on the back cover. Finally a phone that can go in the pocket with your keys, get scratched up, and, like the mutant superhero Wolverine, return to new.
Sort of. Self-repairing technology has been around for a little while, but it remains in its infancy. Bayer Materials, among others, offers a line of such coatings for use in everything from cars to kitchen cabinet doors. The limitation of these materials, however, is that they can only bounce back after relatively minor scratches—where the molecular bonds in the coating are bent rather than broken—and in many cases have to be heated for an extended period of time to do so.
Materials scientists are at work, however, on polymers with more dramatically properties that could actually heal after being cut wide open—more like human tissue and less like fabric being unwrinkled by an iron. One of those researchers is Marek Urban, a polymer scientist at Clemson who works with a sort of molecule called a polysaccharide, a long carbohydrate chain. Urban has been able to modify the chemical composition of the chains so they repair themselves, not only after their bonds are stretched, but when they’re broken. All you have to do to trigger the process is expose the material to light. In one version Urban made, the material turns red where it’s scratched, like a wound, then goes clear once it’s healed. Another variation doesn’t require light, but instead is catalyzed by carbon dioxide—so you can trigger the self-healing by blowing on the cut, the way a mother does on a child’s skinned knee.
Marek says he’s been approached by companies in a variety of industries, from biomedical device makers to defense contractors to automakers to cosmetics producers. “Nail polishes,” he says. “Anything that would extend nail polish for another week would be a huge, huge hit.”