关键词: 微机电系统, 微流体, 速度滑移, Knudsen数, 分子碰撞

Abstract: Stratification theory of the gas film was proposed herein, which was based on molecular motion and collision law of the gas in the film between plates. The film was divided into near wall layer, thin layer, continuous flow layer. And the basis for dividing thin layer and continuous flow layer was also given, in addition, physical model and its corresponding equations were proposed. Flow patterns and pressure distribution in the height direction were simulated and calculated by LAMMPS(large-scale atomic/molecular massively parallel simulator). It is concluded that with increasing gas flow rate, the pressure of gas film is decreased, continuous flow layer thickness is increased, the thickness of the thin layer is decreased. There is no layered pressure in the gas film anymore, velocity slippage may be ignored.

Key words: micro-electro-mechanical system(MEMS), microfluidics, velocity slip, Knudsen number, molecular collision