Pretty soon, you won't be able to hide your limp handshake from someone with a prosthetic arm. At least that's the hope of the team of researchers at Stanford University who developed artificial skin that can sense touch. Engadget describes the team's invention—published Thursday in Science—as "two layers of rubbery plastic skin with a flexible circuit printed on." Billions of electricity-conducting carbon nanotubes are scattered between the layers. The closer they're squeezed together, the more electricity they conduct. "This is the first time a flexible, skin-like material has been able to detect pressure and also transmit a signal to a component of the nervous system," team leader Zhenan Bao says in a Stanford press release.
It's the second part of that process that's proved tricky. NBC News reports Bao and her team used something called optogenetics to show electric signals generated by the skin can get to the brain. Basically, they turned pressure signals into light signals then genetically engineered mouse cells to respond to them. But researchers are still a long way from testing that in a human, and Bao doesn't believe optogenetics is the long-term solution, according to Engadget. The team hopes to one day use their technology to make prosthetics that can feel like human skin, but they still have a ways to go. According to the press release, pressure is only one of six sensing mechanisms—such as friction and temperature—that help skin let you know whether you're, say, petting a cat or a cactus. (A young boy got a new bionic arm from Iron Man himself.)