Simulation of shaped comb actuator for controlled displacement applications

A shaped, interdigitated comb drive is introduced as a viable actuator for microtweezers. The device offers prescribed output force for known actuation voltage steps. As a result, controllable displacement is achieved. Partial device closure and engagement force control are possible through the achieved step-movement. The displacement is linked to the change in capacitance due to the varying engaging geometry of the device.; Finite element analysis is used to simulate the electrostatic actuated, shaped comb drives operating under DC conditions (zero actuating frequency). A parametric multiphysics model is developed using the Arbitrary Lagrangian-Eulerian (ALE) formulation. Results show the coupled interaction between the electrostatic and mechanical domains of the transducer. The analysis is based on the evolution of electrostatic force versus comb finger engagement. The relationship between incremental lateral displacement and actuation voltage illustrates the potential for stepped movement for a shaped comb drive. Additionally, through numerical simulations, this project determines an ideal design for a DC-actuated comb drive, which has controllable force output and stable engaging movement.