e-skin

The dream of having a robot do the dishes may get a step closer with a touch-sensitive electronic skin made of flexible sensors, according to engineers at University of California at Berkeley. And presumably, it wouldn't get dishpan hands.

In a letter published by Nature Materials, the researchers describe a low-power but robust material that would have some of the properties of human skin, such as the ability to feel and touch. Such artificial skin might also help restore limb feeling to amputees.

The e-skin is based on inorganic single crystalline semiconductors. The engineers including Ali Javey and Kuniharu Takei grew germanium/silicon nanowires on a cylinder and then rolled them onto a polyimide film substrate, depositing the wires in a pattern.

The result was a shiny, thin, and flexible electronic material organized into a matrix of transistors, each of which with hundreds of semiconductor nanowires.

A pressure-sensitive rubber was added to the surface of the matrix for sensing. It has the ability to detect pressure from 0 to 15 kilopascals, equivalent to the force needed to grasp light objects. A robot with e-skin hands could handle wine glasses without breaking them.

To show how it can detect pressure, a rubber mold in the shape of the letter C (for "Cal") was placed over the matrix, and about 15 kilopascals of pressure was applied. As seen in the study, the matrix pixels imaged the pressure profile into a blurry but recognizable C.

E-skin for robot applications is under development by other groups, including an MIT-Peratech partnership working on spiky metallic nanoparticles. DARPA, which helped sponsor the Berkeley research, has a Revolutionizing Prosthetics program that is investigating the creation of synthetic skin to improve artificial limbs. … Read more