Contact Research On MEMS Rough Surface

The MEMS is the development and application of science and technology in the research field of micro world. The MEMS products have the promising prospect and potently commercial value. These products play a more and more important roles in the commercial competence. In order to be into market, MEMS faces many key problems , such as the sticking problem, the electrostatic force computing problem, the micro-flow problem, the nano-friction problem, the inspection problem, the membrane stress problem and the surface rough degree problem etc. MEMS would not be obtained a wide market if these problems could not be solved.This thesis discusses the nano-contact that affects the MEMS performance. The nano-contact is firstly analyzed carefully. Secondly, an engineering practical calculation way of the nano-contact is put forwarded and discussed. The main conclusions are following: 1) The "stick" phenomenon is analyzed. The conclusion, which the "stick" problem belongs to the nano-contact problems, is obtained. The research ways of the nano-contact problem are introduced, and emphasized on the molecule dynamic and the continuum medium mechanics. 2) The adhesions of several typical "stick" models are analyzed by the way of continuum medium mechanics. In order to solve the contact problems with the rough surfaces in the practical use, a new model is put forward. The limitations of traditional theory are summarized. In addition, the error rules of the traditional method are analyzed. 3) The rough surfaces with the stick phenomenon are discussed. Take the contact between micro cantilever and substrate as an example, the thesis analyzes the rough surface appearance and establishes a physical model of rough surfaces contact with the random distribution. The conclusion, which the traditional method agrees with the practical adhesion only when the clearance is very small, is obtained. The bigger the gap is, the more obvious the error is. The factors influencing the adhesion are discussed.