Fundamental consideration of piezoelectric multilayer actuators with interdigital-electrode-type structure

This study deals with a piezoelectric multilayer actuator with an interdigital-electrode-type structure. This type of actuator is usually badly damaged when large displacements are generated, because of internal tensile stresses in the actuator. The effect of the number of ceramic layers in the actuator on the internal stress was investigated with the help of finite element simulation and experimentally fabricated actuators. Consequently, the actuator with less than 40 ceramic layers could generate large displacements without destruction, while the magnitude of displacement for the 40-layer actuator was 3.4 mu m for an applied direct current (DC) field of 150V.