LAMINATE TYPE PIEZOELECTRIC ACTUATOR ELEMENT

摘要

A laminate piezoelectric actuator element (10) comprising plural laminated piezoelectric subunits (5) each of which comprises piezoelectric ceramic layers (1) for generating longitudinal electrostrictive strain with a voltage, internal electrodes (2) for applying the voltage to said piezoelectric ceramic layers, and piezoelectrically-inactive portions (7) which correspond to parts of the piezoelectric ceramic layers (1) having no internal electrodes laminated thereon. The piezoelectric ceramic layers (1) and the internal electrodes (2) are alternatively laminated on each other to form a piezoelectric subunit (5). An adhesive member (3) having an attaching area equal to or smaller than an area of each internal electrode (2) is provided between the neighboring piezoelectric subunits (5) to thereby attach and assemble the plural piezoelectric subunits to form the piezoelectric actuator element (10) and form slit portions (9) between the laminated piezoelectric subunits (5) in such a manner as to surround the adhesive member (3). The piezoelectric actuator element (10) further includes external electrodes (4) provided at both sides thereof in such a manner as to be connected to the internal electrodes (2) to apply the voltage to the internal electrodes.