Electronic hair could give robots a more human sense of touch

Electronic-skin prototypes are stretchy, thin films that can sense temperature, pressure and even monitor blood oxygen or alcohol levels. But most of these devices are missing a key feature of real skin that allows us to feel a wider range of conditions: hair. Now researchers at the Harbin Institute of Technology in China have combined hair-like wires with electronic skin to make a more versatile sensor for robots, prosthetics and other applications.

Robots and prosthetics are becoming ever more human-like, but the electronic skins designed to enhance their usefulness don't yet have the full range of tactile senses that we have. For example, they cannot ‘feel’ a light breeze. To capture that sensation, the researchers, Rongguo Wang, Lifeng Hao and colleagues, developed separate sensors that mimic this fine hair by sensing and detecting air flow.

They created an array of artificial hairs with glass-coated, cobalt-based microwires and embedded the ends of the wires in a silicon-rubber ‘skin’. The ‘hairy skin’ could repeatedly detect a range of pressures, including the landing of a fly, a light wind and a 4.5kg weight. When used with a two-finger robot gripping a plastic block, the new sensor was said to ‘feel’ slip and friction forces.