Design and Manufacturing of an Electrostatic MEMS Relay for High Power Applications

This paper addresses the design and manufacturing of a crab-leg based MEMS relay for a high power application. Thanks to a contact resistance lower than 100 mΩ, the relay can hold a current in the order of magnitude of an Ampere without further thermal limitation for the final application. First, an analytical model of the relay, considering its geometry and the contact resistance, is presented. The model is developed in order to focus on the contact deformation. It ensures a low bending moment due to the target contact deformation below 1 nm reducing thus the contact resistance. The design has also been done to overcome the internal resonance frequencies of the future application, i.e. electrical motor. Then, a novel manufacturing process for thicker MEMS is proposed based on micro-fabrication techniques. Finally, the performances of the relay are evaluated and a contact resistance as low as 65 mΩ (comparable to the state-of-the-art) for an applied force of 5 mN, much lower than values reported in the literature is presented.