Enhancement of elementary displaced volume with electrostatically actuated diaphragms: application to electrostatic micropumps

This paper presents two ways to increase the elementary volume which an electrostatic micropump can move. These findings can be used to optimize micropumps in terms of volume stroke. First, the main characteristics of the electrostatic actuator are identified via a simple model based on a rigid plate attached to a spring. Then two different ways to increase the volume stroke by diaphragm deflection are presented. The first is explained via experimental results. In this case, the diaphragm is used in a hard mode by pulling it to the electrode. The second is explained via simulation and is presented with normalized results. Here, by modifying the electrode shape, the pull-in limit can be raised and a larger volume can be achieved.