Analytical model of electrostatic actuators for micro gas pumps

Abstract

We analytically predict the performance of electrostatic actuators for diaphragm micro gas pumps by combining energy minimization and the analytical solution for membrane deformation under uniform pressure. The tangential strain of the membrane is considered in the calculation of membrane deflection. Models for both single- and double-cavity pumps are established to define the restriction of the upper cavity on the membrane during actuation. The shape lines of the membrane in a double-cavity structure are demonstrated under different voltages. The influence of dielectric thickness and cavity geometry on pumping consequence is also discussed. In accordance with other simulation results on diaphragm displacement and chamber pressure rise, an electrostatic diaphragm micro gas pump with a relatively thin dielectric layer and a cavity of comparatively small depth and radius suitably generates high pressure rise. Furthermore, a double-cavity structure enhances pressure rise for the restriction of the upper cavity on the membrane during deformation.