841 hellbaum et al the complete disclosure of which is expressly incorporated herein by reference in such piezoelectric devices the power is generated through the distortion of the piezoelectric device as described in the above incorporated patent piezoelectric device 38 is a layered composite in which individual materials are layered wherein the bottom layer is stainless steel the middle layer pzt ceramic and the top layer aluminum the layers are bonded to each other by means of an adhesive applied therebetween to form a laminate as the laminate is autoclaved during processing the laminate is heated and compressed allowed to cook and then cooled to room temperature during cooling the mismatch in coefficients of thermal expansion cause the material and ceramic layers to contract at different rates thereby putting the ceramic in compression at room temperature this results in a pre stress internal to the individual layers which provides the characteristic curvature of the device the design of piezoelectric device 38 produces relatively high voltage outputs for a given displacement amplitude thereby simplifying system design and packaging at upper end 42 of piezoelectric device 38 mass 44 is secured thereto by any suitable means including soldering bolting a bracket tape or the like mass 44 is preferably a dense material such as a block of lead steel or copper mass 44 is shown in fig2 in a resting position with piezoelectric device 38 extending from engine 20 at point 40 to mass 44 in a direction substantially perpendicular to the direction of movement of the piston as indicated by arrow 28 the transverse.