Optical evaluation of the large signal behaviour of piezoelectric disc actuators to increase the precision of micro diaphragm pumps

Abstract:
The piezoelectric actuator and its electromechanical coupling largely influence the performance of a piezoelectric micro diaphragm pump. Therefore, it is crucial to investigate this property to understand and improve the pump. In this study, we introduce an experimental setup to investigate the large signal behaviour of piezoelectric disc actuators optically using a white light profilometer. Obtained results are reproducible with an error of 5 % and in good agreement with comparative measurements using strain gauges. The comparison of singlelayer and multilayer actuators shows less elongation for the multilayer at same electric fields. However, the multilayer material does not saturate and reaches similar elongation at roughly half the voltage the singlelayer ceramic needs. The introduced setup is well adapted to evaluate actuators prior to piezo mounting to a pump and enables targeted lifetime evaluations.