Piezoelectric pseudo-shear mode actuator made by L-shape joint bonding

A new type of pseudo-shear mode piezoelectric actuator is described which u ses a particular bonding design on a multilayer piezoelectric ceramic stack . In this actuator, long thin rectangular surface electroded PZT piezoelect ric sheets are stacked and epoxy bonded at alternate ends. The poling direc tions in the sheets are selected such that a com mon potential difference a pplied to the plates produces alternate lengthening and contraction through the action of d(31) and thus a cumulative displacement over the whole leng th of the effectively "folded" ceramic. The rectangular stack of plates th us "shears" over to produce a substantial shear angle, hence the title of p seudo-shear mode actuator. In this paper, a new higher strength bonding for the anchoring of the alternate ends is discussed, and shown to permit the generation of large unloaded surface displacements and a high blocking forc e.