Multi-layered piezoelectric bimorph actuator

We have developed a multi-layered bimorph actuator whose power consumption is low and whose displacement is large. Each actuator layer comprises a piezoelectric element and elastic plate. Because volume of the piezoelectric element is constant, the actuator expands in the direction of applied voltage, but contracts in the perpendicular direction. This bends the elastic plate, amplifying displacement. Layer number determines actuator force. We also developed in-pipe locomotive mechanism utilizing the developed actuator and conventional stack type piezoelectric actuator. The power consumption and moving speed of two-actuator mechanism were investigated. The mechanism of the multi-layered actuator moves 2.5 times faster compared with that of the conventional one, and consumes only 1/80 of electric power of the conventional one.