TACTILE SHEAR SENSING USING ANISOTROPICALLY CONDUCTIVE POLYMER

A new technique for tactile shear sensing using a z-direction-only conductive polymer material is discussed. A thin layer of the material is in situ cured, in the presence of a z-direction magnetic field, on the surface of a circuit board containing a contact-pad array. A small metallic cursor embedded in an overlaid elastomeric skin slides over the z-direction conductive polymer upon shear motion, and its change in position is detected by the occurrence of simple circuit connections between neighboring contact pads. This shear sensor has the advantages of being compliant, transparent, able to accommodate pad height variations, and capable of high-resolution sensing. It may also serve as temperature and pressure sensor because of the characteristic and reversible variation of the z-direction electrical resistance in the conductive polymer upon changes in ambient temperature and contact pressure. The new sensor may be useful for potential applications such as touch-sensitive controllers for computer-related products and robotic skins.