Piezoelectric driver device with integral piezoresistive sensing layer

摘要

A unimorph or bimorph piezoelectric 'bender' formed into a flat- (or edge-) wound helix wherein there is an additional laminate layer of a piezo-resistive material 709 the function of which is for sensing and responding to the actual deflection of the bender device. It also discloses a method for making this type of device by co-extrusion of a sinterable paste of the appropriate composition.