Researchers from the Georgia Institute of Technology have fabricated arrays of piezotronic transistors capable of converting mechanical motion directly into electronic controlling signals. The arrays could help give robots a more adaptive sense of touch. Mimicking the sense of touch electronically has been challenging, and is now done by measuring changes in resistance prompted by mechanical touch. The devices developed By Georgia Tech scientists rely on a different physical phenomenon – tiny polarization charges formed when piezoelectric materials such as zinc oxide are moved or placed under strain. In the piezotronic transistors, the piezoelectric charges control the flow of current through the wires just as gate voltages do in conventional three-terminal transistors.
“Any mechanical motion, such as the movement of arms or the fingers of a robot, could be translated to control signals,” explained Zhong Lin Wang, a Regents’ professor and Hightower Chair in the School of Materials Science and Engineering at the Georgia Institute of Technology. “This could make artificial skin smarter and more like the human skin. It would allow the skin to feel activity on the surface.”