Precise control of small displacements of a stacked piezoelectric actuator by means of layer-by-layer driving

This paper describes a stacked (multilayered) piezoelectric (PE) actuator in which both small and large displacements can be generated with a high degree of accuracy. This operation is achieved by driving the individual layers of the multilayered PE actuator. Such multilayered actuators are sandwich-structured, with a thin, (/spl sim/50 /spl mu/m) electrode layer between each pair of thin (/spl sim/100 /spl mu/m) PE-ceramic layers, so driving an individual layer of the stacked PE actuator was difficult. This difficulty was overcome by using polyamide deposition and a YAG-laser process so that each layer had an individual connection to the power supply. Each layer of the present multilayered PE actuator is thus driven by a corresponding pair of electrodes, and each pair of electrodes can be individually controlled.