PIEZOELECTRIC ACTUATOR, PIEZOELECTRIC VIBRATION DEVICE, AND MOBILE TERMINAL

摘要

[Problem] To provide a piezoelectric actuator, a piezoelectric vibration device, and a mobile terminal, with which even greater flexural vibration can be achieved. [Solution] This piezoelectric actuator (1) is characterized by being provided with: a stacked body (4) having, stacked therein, internal electrodes (2) and piezoelectric layers (3); and surface electrodes (5) on one main surface of the stacked body (4), said surface electrodes (5) being electrically connected with the internal electrodes (2). The piezoelectric actuator (1) is further characterized in that: the internal electrodes (2) include first poles (21) and second poles (22); an active section (41) in which the first poles (21) and the second poles (22) of the internal electrodes (2) overlap each other in the stack direction, and inactive sections (42) in addition to the active section (41) are included; the thickness of the active section (41) is greater than that of the inactive sections (42); and another main surface of the stacked body (4) is flat.