Piezoelektrischer Aktuator

摘要

A piezoelectric actuator in which of the piezoelectric layers 23a and 23b, being the outermost layers of an actuator body 26 with a layered structure onto which are formed an outer electrode 31 and an outer electrode 32 on both end surfaces 29 and 30, the piezoelectric layer 23a is made piezoelectrically active as a result of making an extension portion 34 of the first outer electrode 31, through the piezoelectric layer 23a, face inner electrodes 25 with a polarity which is different from that of the extension portion 34, while the piezoelectric layer 23b is made piezoelectrically inactive as a result of either making an extension portion 35 of a second outer electrode 32 face, through the piezoelectric layer 23b, the inner electrodes 25 with a polarity which is identical to that of the extension portion 35 of the second outer electrode 32 or as a result of not forming an extension portion on the outer electrode. This causes the displacement value caused by bending to be added to the usual d31 component displacement, thereby increasing the amount of displacement as a whole.