Fatigue and retention properties of the shape memory piezoelectric actuator

Abstract

The piezoelectric actuator generates mechanical strain by application of the external electric field due to its piezoelectricity. The piezoelectrically induced strain is principally linear with the applied electric field. Thus, in order to maintain its piezoelectric displacement, continuous dc voltage is required. On the other hand, the shape memory piezoelectric actuator which we recently proposed has different property. The shape memory piezoelectric actuator utilizes the domain switching strain, which is irreversible strain. Utilizing the domain switching, the actuator generates irreversible displacement by application of a pulsed voltage. In other words, the actuator can maintain its displacement without voltages. For the shape memory piezoelectric actuator, its retention property without voltages is important. In this study, the fatigue by continuous cyclic operation and the retention property were investigated.