Effect of Electrode Pattern on the Performance of Unimorph Piezoelectric Diaphragm Actuators

摘要

This paper presents a study in which clamped unimorph piezoelectric diaphragms are tested to determine the importance of the pattern of the electrodes that supply the driving charge to the actuator. In previous work, it has been shown that such a diaphragm, when used as an energy harvesting device, can generate a much increased charge in response to an applied pressure when the electrode has a "regrouped" pattern. Regrouping refers to the process of segmenting the electrodes into regions that are electrically disconnected and then reconnecting those regions such that some have reversed polarity. The circular diaphragm actuator studied in this paper works somewhat the opposite of an energy harvester. That is, applied charge is used to generate diaphragm deflection as opposed to applied pressure generating charge. Four unimorph diaphragm actuators, with different electrode patterns, were tested in this work. According to analytical and experimental results, it is shown that a factor of seven increase in diaphragm deflection can be obtained with regrouping.