Simulation Study and Reliability Analysis of Low Actuation Voltage Cantilever Based RF MEMS Switch

This paper reemphasizes the importance of material consideration to design a low pull-in voltage MEMS switch. We have simulated different variants of a cantilever-based MEMS switch with variations in length, thickness, and material of the cantilever beam. The simulation study provides an understanding of a suitable cantilever design to achieve low operating voltage MEMS switch. We have further simulated the mechanical properties of these designs of the cantilever beam for a low operating voltage by computing the equivalent electrostatic force which is the input to the mechanical simulations performed using ANSYS. The electromechanical simulation provided similar trends of deflection and validates some aspects of the cantilever beam design especially for the material choice that can aid to achieve a low actuation voltage. The paper also provides a better understanding of the deflection variations that can be seen with change in material; when a switch is actuated, the deflections for actuation hover around 2/3rds of the gap in a cantilever-based RF MEMS switch with a standard deviation of 0.3 μm. The key contributions of the paper is: 1) showing that the cantilever beam design is critical for achieving low actuation voltage, 2) deflections of the cantilever at actuation voltage depends on the material used and can be around 2/3rds of the gap and can be slightly less for some materials, and, 3) a comparative simulation study between electrostatic and mechanical simulations to provide information on structural integrity of the simulated cantilever beams for MEMS switch.