Testing and simulation of comb-driven MEMS relay by applying digital image correlation technology

In this paper, digital image correlation (DIC) technology is developed to measure the in-plane deformation of the MEMS relay by using an optical microscope with a CCD camera. The mechanical-electronic behavior of a bulk-micromachined relay driven by a comb actuator for lateral motion is tested and simulated. Due to the small size, the deformation measurement of the MEMS relay is very difficult in a macroscopic scale. The digital image correlation technology was employed to determine the dimensions and displacements of the MEMS relay. Based on the video films and the collapse deformation of the structure, the pull-in voltage was obtained that represented the instability characteristic of the micro-system. Meanwhile, the instability behaviour of the MEMS relay was numerically simulated with an electronic-mechanical coupling analysis. The simulation results are in good agreement with the experimental ones, which verify the feasibility of the DIC technology for other MEMS devices.