Electrostatic pull-in analysis of a nonuniform micro-resonator undergoing large elastic deflection

Pull-in analysis of an electrostatically actuated nonuniform micro-resonator under large elastic deflection has been investigated with a focus on qualitative analysis to understand the essence of nonuniform cross-section on the determination of pull-in voltage. Here, a microcantilever beam with nonuniform cross-section has been adopted to develop a mathematical model considering the important features such as structural nonlinearities, nonlinear electrostatic distribution, and linear viscous effect. The individual effect of each design variables on the diagnosis of the critical voltage and corresponding critical deflection due to pull-in has been graphically depicted. The results in the static condition have been verified with the findings obtained via COMSOL multi-physics software. Present result indicates that a nonuniform microbeam configuration strengthens the structural stability by switching the pull-in voltage up to a higher value. Similarly, stable pull-in deflection within the restriction of pull-in instability has been also augmented. In addition, it has been shown that the nonuniformity within the beam structure is highly sensitive to the nonlinear effects. Hence, outputs provide a useful insight of pull-in behavior and enable an understanding of safe and smooth operating range of microelectromechanical system devices.