Investigation Of Microcantilever Electromechanical System Dynamic

Micro-electro-mechanical system (MEMS) is a multidisciplinary technology. As one of the most important branch, MEMS dynamic is following the self-development of MEMS to become a new research area and focus gradually. Micro-cantilever is a typical structure and key component; therefore its dynamic characteristics affect design and performance of electromechanical coupled micro system directly. In this paper, the dynamics of micro-cantilever electromechanical coupled system was investigated.First, the characteristics of air damping, including sliding film damping and squeeze film damping was investigated. The model of sliding film damping and squeeze film damping, as well as damping coefficient were presented using Navier-Stokes equation and Reynolds equation respectively. Numerical simulation and ANSYS simulation were used to analyze the theoretical results of air damping.Second, the dynamic characteristic of micro-cantilever system under electrostatic actuation was investigated. The continuous model and nonlinear dynamic equation were analyzed using nonlinear dynamic method, such as KBM and IHB (Incremental Harmonic Balance) method. The relationships between structure parameters and system performance parameters, such as static displacement, natural frequency, dynamical response of free vibration and forced vibration were discussed by numerical simulation. On the basis of damping and micro-cantilever dynamic investigation, dynamic behavior of laterally oscillating micro comb-driven resonator was studied. The important performance parameters of resonator, such as natural frequency, comb capacitance, frequency response curve and quality factor were analyzed and discussed using ANSYS simulation and numerical simulation.Finally, nonlinear dynamic behavior of tapping mode atomic force microscope(AFM) under bounded random noise excitation was investigated. The micro-cantilever was modeled with a lumped-parameter model and the interaction between the micro-cantilever and sample was described by the Lennard-Jones (LJ) potential. Effects of the density of the random disturbance, material property parameter and contact angle of the meniscus force on the dynamic system were analyzed and discussed.