High displacement, high force piezoelectric actuator and sensor

Abstract

A piezoelectric actuator and sensor which develops unusually high forces and displacements, and which is very rugged and durable, was invented by NASA at the Langley Research Center, Hampton, Virginia. Face International Corporation, under license from NASA Langley, has furthered the development of this actuator/sensor technology, and has successfully brought it to commercial production. Trade-named THUNDER, the device derives its improved performance from two unique features. First, THUNDER is composed of a piezoelectric ceramic core which is enclosed in a sandwich having metal foil faces. The metal faces are bonded with a very strong hot-melt adhesive which enables the actuator, operating as a unimorph, to develop large displacements and support heavy loads without failure. Second, through unique design features, the ceramic core of THUNDER is subjected to thermal expansion during manufacture. The thermal effects place the faces of the ceramic in compression so that it can undergo severe bending without cracking. The combination of the described design features of THUNDER permit its operation as a sensitive motion sensor and voltage generator as well as making it a superior solid state actuator.