For years, researchers have been working to replicate the delicate sense of touch in robots. So far, the prototypes have been complicated and costly.
But now a team of Chinese scientists has built a much cheaper, simpler version of the technology, which they say could deliver "unprecedented opportunities" for artificial intelligence.
The hardest part of building artificial skin is sensitivity. A low-sensitivity skin is fairly easy to construct, but ramping the sensitivity up usually requires boosting the number of embedded electrodes. That increases both costs and the bulkiness of the skin.
To avoid this problem, the Chinese team came up with a method for detecting contact location and pressure using electrostatic induction - the same technology used in wireless charging devices. It measures the change in an electric field when another electric field passes nearby.
The resulting skin, created from ultra-thin plastic film, contains just four electrodes - compared to other prototypes of a similar size that contain up to 36. In tests, it proved to be sensitive enough to "feel" a honey bee that flew towards and away from the skin.
Even more impressively, it also harvests mechanical energy from a robot's movements and turns it into an electric current. That makes it entirely self-powered, avoiding the need for batteries and wires to be attached.
As well as allowing for robots that can sense the world around them, the technology could also be used in prosthetics to allow amputees to regain a sense of touch. A similar 'skin' could be applied to the surface of an artificial hand and connected to the body's nervous system.
The research was published in the journal ACS Nano.