Sensitivity enhancement of a MEMS sensor in nonlinear regime

The aim of this study is to enhance the sensitivity of a micro electro mechanical Gyroscope in nonlinear regime. Sensitivity enhancement is achieved by applying appropriate Hoping voltages which pushes the micro-beam to the basin of attraction of a desired periodic attractor. The studied model is a silicon clamped–clamped micro beam actuated by an electrostatic voltage which is a combination of a constant DC and a harmonic AC voltage in the drive mode direction and a pure DC voltage in the direction of sense mode. The external angular velocity about the horizontal axis is used to create the Coriolis force along the sense mode. The governing differential equation of the motion is derived using Hamiltonian principle and discretized to two nonlinear Duffing type ODE’s using Galerkin method. Shooting method is utilized to obtain the frequency response curve, and to capture the periodic solutions of the motion. The stabilities of the periodic orbits are investigated by the Floquet theory. The results depict that the response of the system is highly affected by the applied DC and AC voltage; corresponding to a constant DC voltage, the more is the AC voltage, the more is the sensitivity. Based on the DC voltage the system exhibits both hardening and softening effects. The capacity of the capacitors is determined and the effects of the various applying Hoping voltages on capacity of them are investigated. The frequency response curve of the micro-beam for various quality factors are obtained and compared with the literature.