1991 Articles

Microcavity vacuum tube pressure sensor for robot tactile sensing

White, R. C.; Allen, Peter K.; Jiang, J. C.

A novel microstructure pressure sensor for robot tactile sensing is currently under development. The design is based on a silicon vacuum diode configuration, which has a cold field emission cathode and a movable diaphragm anode. The cathode is a sharp tip. When a positive potential difference is applied between the cathode tip and anode, an electric field is generated at the tip that allows electrons to tunnel from inside the cathode to the vacuum outside, if it exceeds about 5×107 V/cm. The field at the tip and the quantity of electrons emitted or emission current are controlled by the anode potential. The anode deflects in response to differential pressure to produce current-change.