A Simple Method for Extracting Piezoelectric Coefficient d31 by Fitting Experimental Data with an Analytical Model

This work presents a simple method to extract the piezoelectric coefficient d31 based on analytical model fitting. A theoretical circuit model is developed for a piezoelectric circular membrane actuator based on PZT thin film. The circular diaphragm consists of a 12 µm silicon layer, an 800 nm thick PZT layer, and a 200 nm Ti/Pt layer, featuring a single 50% inner top electrode coverage. The proposed model is validated by the finite element method with a 2D axisymmetric model of a PZT piezoelectric membrane. Further, piezoelectric coefficient d31 is extracted by fitting the Laser Doppler Vibrometer (LDV) experimental result with the analytical model.