A Mew Model for an Electrostatically Actuated Miniaturs-Scale Diaphragm Compressor for Electronics Cooling

摘要

This paper presents a new approach for quasi-static modeling of an electrostatically actuated diaphragm compressor for miniature-scale refrigeration systems that can be used in electronics cooling. The compressor consists of a flexible circular diaphragm that is clamped at its circumference. A dome-shaped cavity encloses the diaphragm completely. Two valves control the inlet and discharge flows. Metallic electrode layers are deposited on the membrane and on the cavity surfaces. A potential difference is applied between the diaphragm and the cavity to pull in the diaphragm towards the cavity surface progressively from the outer circumference towards the center of the diaphragm. This zipping action reduces the volume available to the refrigerant gas, thereby increasing its pressure. The model developed in this paper uses a segmentation technique where the diaphragm is divided into a series of parallel-plate capacitors with movable plates that simulate the diaphragm deflection during actuation. For a sustained zipping actuation, the electrostatic force between the parallel plates must be higher than the elastic force induced by the stretching of the diaphragm and the pressure force of the fluid being compressed. A diaphragm pull-in voltage is calculated for a given geometry, material properties and pressure ratio. The model is compared with the literature and the results show a reasonable correlation.