One challenge for artificial limbs — whether they are attached to a robot or to a human as a prosthetic — is to sense pressure. The feedback from your fingertips tells you if you are gripping an object firmly enough. If it starts to slip, you can sense it and tighten your grip. This is difficult for artificial skin, but a group of Korean researchers may have the solution according to a paper published in ACS Nano.
The material is flexible; it can both bend and stretch, and still work. What’s more, it can sense the difference between four different forces: stretching, bending, direct pressure, and a shear or sliding force. The skin uses tiny plastic domes of piezoelectric material packed in a tight matrix. As the domes deform, they touch each other, creating new channels for electrical current to follow. The material is so sensitive that it can register the direction of air flowing over the artificial skin.
If this material can be produced at a reasonable cost, it could transform robotics and prosthetics. It would give them a skin that would approach human skin in its ability to sense its surrounding environment.