Patent ID: 7823467

Claim:
A tactile sensor capable of determining a direction from which a force is applied, comprising: (a) an electroactive polymer comprising: (i) an ion-exchange membrane formed into a convex dome having an outer surface and an inner surface; (ii) a plurality of flexible electrodes disposed on the outer surface of the ion-exchange membrane, so that each of the plurality of flexible electrodes covers a different circumferential segment of the outer surface of the convex dome; and (iii) a base flexible electrode disposed on the inner surface of the ion-exchange membrane; (b) a plurality of electrical conductors that are electrically connected to the plurality of flexible electrodes and to the base flexible electrode to convey output signals from the plurality of flexible electrodes and the base flexible electrode, wherein distortion of a segment of the ion-exchange membrane caused by a force applied to the flexible electrode covering the segment causes the segment of the ion-exchange membrane to produce an output signal indicative of a magnitude of the force, wherein relative differences in the output signals conveyed from the flexible electrodes covering the different segments of the convex dome are further indicative of a direction of the force acting on the tactile sensor; and (c) an elastomeric support disposed within a concave cavity formed under the convex dome, the elastomeric support preventing a force applied against one or more of the plurality of flexible electrodes from inverting the ion-exchange membrane.