Micromachined active tactile sensor for detecting contact force and hardness of an object

We propose a new type of micromachined tactile sensor that can detect both the contact force and hardness of an object. It consists of a diaphragm with a mesa structure, a piezo-resistive displacement sensor on the diaphragm, and a chamber for pneumatic actuation. We designed the device so that it detects the touch of human finger distinguished from that of hard bodies. We fabricated devices by micromachining technologies to prove the principle. The sensor element is 6.0 mm/spl times/6.0 mm/spl times/0.4 mm, and it has a displacement sensing element of piezo-resistor at the periphery of the diaphragm structure. We experimentally confirmed the characteristics of the device by using pneumatic actuation.