The majority of micropumps developed result in pressure differences of less than about 3 mH_2O. In this work, a vacuum micropump with cascaded chambers is proposed; it is composed of two layers of reciprocal actuated membranes and two layers of check valves. Design of the vacuum micropump with electrostatic and piezoelectric actuators as well as cantilever check valves is proposed. The selection of actuation modes and actuation valves is addressed. Two theoretical design functions are derived to calculate the maximum attainable vacuum with the operation rounds of the membranes and the cascaded stage number. The analyses suggest that large membrane displacement, small dead volume of the chamber, and small backward leakage rate are preferred in obtaining higher vacuum. The increase of chamber stage numbers results in an exponential increase of the vacuum. The relationship between the vacuum and operation rounds is also similar to that between the vacuum and stage numbers: the more rounds the vacuum micropump is operated for, the higher the vacuum is obtained. The designed vacuum micropump can be integrated into the current IC techniques with batch production and high pumping ability.
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