Behavior of unimorph rectangular piezoelectric diaphragm actuators

This paper presents a study in which clamped unimorph rectangular piezoelectric diaphragms are analyzed to determine the importance of electrode patterning. There has been a great deal of interest in getting increased deflection out of smaller piezoelectric devices with lower input power. In previous work, it has been shown that a clamped circular diaphragm can generate much increased deflection in response to an electric loading when the electrode has a "regrouped" pattern. Regrouping refers to the process of segmenting the electrodes into regions that are electrically disconnected so that the corresponding polarity can be set in opposite directions. The rectangular diaphragm actuator is studied in this paper to determine the effects of electrode patterns and the shape of the piezoelectric layer on the actuator's static displacement. From the analytical results, it is shown that regrouping the electrode pattern on a rectangular actuator can increase deflection, and subsequently volumetric displacement, by many times.