Use of Piezoceramics as DC Actuators in Harsh Environments

摘要

Changes in the electrical resistance of PZT actuator materials under conditions of high DC bias, high humidity and moderate temperature have been studied with a view to improving the lifetime of DC actuators. Testing has mainly concentrated on the monitoring of the DC conductivity during exposure, but additionally PE loops and strain-field measurements have been carried out in-situ. Optical and Scanning Electron microscopy have been used to examine the samples after exposure. The results show that while the DC conductivity of the material increased, the piezoelectric nature of the material is preserved, and provided that the sample does not short circuit it will still function as an actuator. The cause would appear to be due to electromigration of the electrode material, although no direct evidence was found to support this.