Instantaneous Evaluation of Friction Based on ARTC Tactile Sensor

A human can lift up an object with almost minimal grasping force regardless of the fiction coefficient between the fingers and the object, but the sensing mechanism for this remarkable task has not been well explicated yet. In this paper we propose a tactile sensor to detect a fiction coefficient at the moment of touch. With this sensor output we evaluate the largest lifting-force just before a slip happens, without any preliminary motions. The sensor has a sensing cell in the elastic body, which measures straidstress components parallel and vertical to the suface. Those plural stress/strain parameters at a point gives the fiction coefficient. A prototype sensor is fabricated with acoustic resonant tensor cell, and we examine that principle in experiments.