Theoretical Analysis Of An Electrostatic Micro Pump With Membrane Actuator And Research On Related Bonding Technologies

Micro pump is the key component of a micro fluidic system and it has been widely researched and applied in the field of MEMS. Most micro pumps are used to pump gas or liquid with few pressure rise at present. The micro pump with high compression ratio is hard to develop because of the difficulty from operation mechanism and manufacture technologies. Such kind of micro pump can be planted into micro refrigeration system which is desirable in micro cooling of electronics.Electrostatic actuated micro pump is a good candidate for such application because electrostatic actuation can work under high frequency with fast-response. For future applications, a lot of modifications and improvements must be made to increase the pressure rise, Such as pump structure, material, modeling, optimization, micro-machining, MEMS techniques, bonding technique and fabrication. In this paper, the first half introduces a novel analytical model of electrostatic actuated membrane for micro pump. Then, the work focus on the manufacture of pump components and research on bonding technologies.An analytical model of electrostatic actuated membrane for micro pump with dual-cavity structure is done here. The model couples with applying energy conservation theory and test function method is used to predict the membrane shape at equilibrium and the pressure rise. Based on this model, parametric studies are carried out as well for better understanding of the electrostatic compression system. Through improvements step by step, pressure rise above 0.1MPa is proven to be possible.In the manufacture of micro pump, the pump cavity, the membrane and dielectric layer are made by micro-machining and MEMS techniques. In the research on bonding mechanism of micro pump, an aromatic thermosetting copolyester (ATSP) is synthesized in our lab to use as adhesive in solid-state bonding for silicon dioxide and polyimide. The tensible strength at bonding interface is above 1.5MPa in testing, which is adequate for application in micro pump fabrication.The analytical research on micro pump in this paper is helpful to design and manufacture of micro pump with electrostatic actuator. The research on low-temperature solid-state bonding technologies is important to micro pump fabrication. It can also promote the further application of polymide in the field of MEMS and electronics.