Research On Micro-Electromechanical Systems And Nano-tribology

With the development of Mechanics and Electronics incorporating and the infiltration of micro-electronics technology coming into every field of mechanical engineering, the microminiaturization of mechanism has been great accelerated. In recent years, with the development of Micro/Nano Science and Technology, MEMS marked with tiny shape and small operation size have become a high-technique to understand and rebuild the world in microcosmic realm. As the dimension reduces to a certain range, however, many physical phenomenon are quite different from that of the macro-view world, especially in the case of friction. The phenomenon of tribology have been studied with the synthetical analysis based on experiment investigation for many years, and people have found many disciplinarians and brought many acting models, but still it is hard to know the real principle of friction. With the reducing of the objects'dimension and lucubrating in friction, many experiments indicate that the classic Amontons formula: F =μNfalls short of the law of micro-friction obviously. Researchers have found that the friction keeps direct ratio with slipping velocity of a interface in atomic scale. Even in macro scale, the friction modulus is not a constant, it varies with the slipping velocity. This has been proved in the rubber friction experiment.As there are so many conflicts between the phenomenon above and the classic theories, the thesis starts off with the Hertz contact theory, using the relation between microshape change and force, we analyse the cause of friction, and prepare for the elastic contact model. The Fuzzy Set has been introduced, and we list some membership functions in common used. Using the Fuzzy theory which connect the accuracy and the illegibility, we can turn the uncertain factors in friction research to believe. A half-microspherical model simulating the surface shape of solid is founded by Greenwood-Williamson(GW) model. Raising a surface single half-microsphere contactive elasticity model based on Hertz theory, we build dynamical equations. We adding the dynamical equations with the membership function, and gained the relation between Micro/Nano friction modulus and slipping velocity(μ? v). It products a effective method to research the principle of Micro/Nano friction.