Researchers at Stanford and also UC Berkeley have developed ultra-sensitive artificial skin. For example, the Stanford group's elastic polymer "skin" detected a fly and butterfly on it, expressed by a change in the amount of electric charge the materials could hold. The UC Berkeley researchers constructed their skin from a grid of semiconductor nanowires laid out on pressure-sensitive rubber. Each nanowire intersection functions as a transistor "pixel" that changes current based on the pressure. While prosthetic skin is a long-term goal, the nearer application is in robotics. From Nature News:
Fully working artificial skins will need to do more than detect pressure and bend. "The ultimate prosthetic skin should behave like our own skin," says Stephanie Lacour, a materials scientist from the University of Cambridge, UK. That would mean the skin being able to detect sideways shear forces – such as those produced by scratching a twig down your leg – as well as pressure. "This is one of the most difficult things to implement," she says.(UC Berkeley's Ali) Javey agrees that there are many challenges to overcome to make a fully functional artificial skin, not least integrating that skin with the brain. But applications in robotics could come much sooner, he says. The next step is to scale up production so that enough artificial skin can be made to cover an entire robot's body, Javey says.
"Artificial skins detect the gentlest touch"
