PIEZOELECTRIC ACTUATOR

摘要

A piezoelectric actuator where increase in external dimensions is avoided, that has large vibration amplitude, whose resonance frequency is adjustable, and that has high reliability. A piezoelectric actuator has a piezoelectric element (1a) having a piezoelectric body (3a) whose at least two opposite surfaces expand and contract depending on condition of an electric field, a restraining member (21a) for restraining the piezoelectric element (1a) at at least either of the two surfaces, a supporting member (4a) provided around the restraining member (21a), and beam members (22a) in which both ends of each of the beam members are fixed to the restraining member (21a) and to the supporting member (4a) and having a neutral axis of bending, the axis being in the direction substantially parallel to the surfaces to be restrained.