Displacement Analysis of a Piezoelectric Based Multi-layered Micropump Diaphragm

Abstract

This paper presents the diaphragm displacement analysis of multi-layered circular piezoelectric actuator (MCPA) using analytical, numerical and experimental methods. The piezoelectric zirconate titanate (PZT) actuator model examined in this study consists of a structure with 3 different diameters and 7 layers. The multi-layered and multi-covered actuator model was composed of three main layers in different radii and thickness with silicon, brass and the PZT and four additional layers with silver and bonding. When creating an analytical model, the effects of all layers were taken into account on the static deflection performance of the actuator. The classical laminated plate theory based on Kirchhoff thin plate theory was used in the analytic modelling studies of the actuator. The mathematical model, which is the solution of the static displacement equation of the non-homogenous for the MCPA of the micropump, depends on the applied voltage and pressure load together with the material and physical properties. The electric-solid coupling of the piezoelectric actuator and the silicon diaphragm layer under the effect of applied voltage load, and the silicon-fluid coupling under the uniform fluid pressure were simulated by numerical modelling with finite elements. In addition, the maximum displacements of the MCPA with silicon exposed to uniform flow pressure and electric voltage load were measured at different frequencies experimentally. It was observed that the results obtained from the analytical model, finite element analysis and experimental studies were sufficiently compatible with each other. Using the verified analytical model, the effects of layer thicknesses, layer diameters and adhesive layer on actuator static displacement performance are discussed.