"Soft" and "gentle" are two words not often used to describe the grasp of a robot, but thanks to the work of a team of researchers at Cornell University, future androids may well have an especially delicate touch. Using extra-sensitive optical detectors built into a soft prosthetic hand, the researchers have demonstrated a prototype that is able to tell by touch whether fruit is ripe, or to modify the pressure exerted on a material simply in response to the way it feels.

The prototype made use of a combination of LEDs and photosensors incorporated in bendable tubes (known as elastomeric optical waveguides) and used as detectors of curvature, elongation, and force. These were then embedded in a stretchable, soft artificial hand, allowing the researchers in the Organic Robotics Lab at Cornell to use these devices to electronically register a large range of feedback and control the hand accordingly.