The compact modeling (or macromodeling) method for the MEMS devices is the key issues in MEMS system design and system level simulations. For constructing the compact modeling of the nonlinear silicon diaphragm actuated by a distributed electrostatic force

a nonlinear function fitting scheme is used after several finite element analysis running

where the energy date are calculated for constructing an analytical model of kinetic energy

strain energy and electrostatic co-energy of the system. Then all theses energy function is represented in the term of general mode coordinates and subjected into the Lagrange Equation to deduce the motion equations of the silicon diaphragm. Thus the macromodel was obtained. After that the macromodel was used to simulate the device’s quasi-static and dynamic characteristics. The simulation results were compared with the results calculated by finite element method. All results show that the compact model can capture the quasi-state and dynamic behaviors of the electrostatically actuated silicon diaphragm quite well. This compact modeling method can consider the effect of residual stress and geometry nonlinear and has a low computational cost.