Miniature pressure sensor and pressure sensor arrays

Abstract

An improved pressure sensor element and pressure sensor array is formed by a cathode layer, a cathode tip attached to the cathode layer, and an anode layer opposing the cathode layer. The magnitude of the electron current flowing between the cathode tip and the anode layer is dependant on the field strength at the cathode tip, which is dependant on the separation between the cathode tip and the anode layer. As a deflectable anode layer is deflected towards the cathode tip, the field strength increases, causing a corresponding change in the magnitude of the flow of electrons. The cathode tip is separated from the anode layer such that electron current is produced at relatively low voltages by tunneling or field emission. The exact method of current production is selected by controlling the initial separation between the anode layer and the cathode tip. Pressure sensor elements are produced using a series of fabrication processes including forming a hole in an insulating layer deposited on the cathode layer, depositing a cathode having a cathode tip into the hole thus formed, and bonding the anode layer onto the insulating layer, thereby forming a pressure sensor element. A plurality of pressure sensor elements are fabricated into pressure sensor arrays by this method. Pressure sensor elements or pressure sensor arrays are thus produced at low cost.