Scientists dream of prosthetics and robots with electronic skin that can convey heat and pressure just like the real thing, but there's a big problem getting in the way: the outside world. Bumps and scrapes can damage these sensors, and it's not really practical to toss these skins in the trash when they're no longer useful. UC Boulder researchers hope to fix that. They've developed an e-skin that can communicate temperature and pressure, but is both self-healing and fully recyclable. You could take a cut on a synthetic arm without panicking, and reuse any damaged 'tissue' to make replacements.
The trick is the use of a unique polymer (polyimine) laced with silver nanoparticles. It can still conduct electricity and withstand stress, but its covalent atomic bonds make it both self-healing and recyclable at room temperatures. It just has to use widely available ethanol compounds to patch itself up, and you can degrade the polymers using a recycling solution that separates the silver from the skin in question.
Any practical uses are a long way off, but they're definitely on the horizon. You can easily use a modest amount of heat and pressure to make the skin wrap around curved surfaces, so it's ideal for smart prosthetics or advanced robots that may need both ruggedness and a delicate grip. All told, e-skin is becoming more of a practical reality outside of the lab.