Dynimic Characteristics And Flow Analysis Of Electro Micropump

The rapid development of micro-electro mechanical systems (MEMS) is remarkable.The micro fluidic system is an important part of the MEMS，of which micro pump is thekey execution unit. Electrostatic micro pump is a common micro pump structure, with theadvantage of short response time, small power consumption, good reliability and ICprocess compatibility, which has broad application prospects. This paper mainly presentsthe pump membrane vibration characteristics and port flow characteristics of theelectrostatic micro pump.First, the differential equation of undamped free vibration of electrostatic micro pumpmembrane is established. The natural frequency and modal shapes of the pump membraneare solved. The characteristics of mode shapes are also analyzed. How the structureparameters of pump membrane affect the natural frequency is analyzed as well.Secondly, the electrostatic driving force of the electrostatic micro pump is presented,and the static displacement of the pump membrane is solved. The requirement preventingpump membrane from being attracted to fixed electrode is analyzed, and the dynamicequation of pump membrane in the operational state is established. The free vibration ofthe pump membrane under the constant voltage and the squeeze film damping, as well asforced vibration under fluctuant voltage are solved by KBM method.The port characteristics of electrostatic valveless micro pump are researched, as wellas the efficiency of the pump. The micro pump flows under several different conditionsare calculated separately. The flow output characteristics of electrostatic valveless micropump are studied, and the influence of different parameters on the electrostatic micropumpflow is analyzed as well.It is quite difficult to optimize the structural parameters of the micro pump directlybecause that the constraint is complicated, and the optimization problem is appropriatelysimplified. The deformation amount of the pump membrane under the same conditions issetted as the optimization target, and then optimization for the pump membrane size isconducted. Modal analysis of pump membrane is conducted by the finite element softwareANSYS, and several mode shapes and natural frequencies are solved. By using ANSYScoupled analysis method, the static deformation of the pump membrane under a constantvoltage is solved as well. The theory is verified to be logical.