JP2645628B

PURPOSE:To prevent generation of stress breakdown due to concentration of stress strain at the boundary between an active region and an inactive region, prevent insulation breakdown, and then increase the amount of displacement to be generated. CONSTITUTION:A number of thin plates 10 where an internal electrode 14 is formed are laminated on the surface of an electrostrictive/piezoelectric material 12 and then each internal electrode is alternately connected at every other layer by a pair of external electrodes. Each thin plate is provided with an electrode leading part 16 for continuing the internal electrode to one of external electrodes and an electroless part 18 for preventing continuity between the internal electrode and the other external electrode. N types of electroless parts which are different in width are avaliable (N; an integer) >=2). Then, assuming that their relationship is W1