Abstract

A tactile sensor for sensing an object in contact therewith. In its preferred form, the sensor comprises a plurality of layers disposed in a sandwich arrangement. A top layer is comprised of a flexible, electrically-insulating material and a plurality of parallel flexible conductive rods. A bottom layer is comprised of an electrically-insulating material and a plurality of parallel conductive rods that extend at right angles to the conductive rods of the top layer, thus forming a sensory array comprising a plurality of superimposed intersection points arranged in a grid pattern. An intermediate layer is comprised of a resilient, electrically-insulating material in which is disposed a plurality of parallel conductive posts that extend perpendicular to the plane of the three layers. These posts are comprised of a resilient conducting material. Each conductive post is disposed at one of the sensor's aforementioned intersection points so as to electrically couple one of the conductive rods of the top layer to one of the conductive rods of the bottom layer. The conductive rods are formed with a selected cross-section, in order that changes in the amount of pressure exerted on the sensor will produce corresponding logarithmic exchanges in the contact surface area, and hence electrical contact resistance, established between the conductive rods and those conductive posts disposed beneath the points of pressure.