Research On Influence Of Fluid Damping On Resonance Characteristics Of MEMS Cantilevers

As the advantages of miniaturization,integration,intelligence,low cost and high efficiency,Micro/Nano-Electronic-Mechanical System(MEMS/NEMS)is considered to be another technical field which has a significant impact on the national economy and military after microelectronics.MEMS technology has become one of the indispensable technologies in the domain of biomedicine,resource exploration and mechanical engineering.The micro cantilever is the key object for the MEMS sensor,and has been widely used in the complex environment,such as liquid,gas,high temperature,high pressure and so on.The vibration characteristics of microcantilever structure are different in different fluids.Therefore,this article will explore the reasons for this difference.According to the theory of hydrodynamics,We can divided the fluid damping into added mass and viscous damping.When the Reynolds number of fluid Re is greater than 1000,the magnitude of added mass of fluid is greater than that of viscous damping,and then we can ignore the effect of the fluid viscosity.When the Reynolds number is less than or equal to 1000,the magnitude of added mass is equal to that of viscous damping,so we cannot ignore the effect of the fluid viscosity.Now we need to make clear the influence of these two damping on the resonant characteristic of the microcantilever.Therefore,we divided the fluid into two aspects,one is viscous fluid and the other one is non viscous fluid,and the vibration characteristics of the microcantilever structure in the two aspects are analyzed respectively.The innovation of this papers to created a new model of FEM fluid structural interaction,and further design the micro observation platform,vacuum equipment and laser displacement measuring equipment.And then the vibration test of microcantilever structure under different vacuum degrees is carried out.Finally,the three results of experiment,simulation and theory are compared and analyzed,and the correctness of our experiment and simulation of finite element is verified.