4 W Power MEMS Relay With Extremely Low Contact Resistance: Theoretical Analysis, Design and Demonstration

Abstract

This paper reports on the unprecedented 4 W power microelectromechanical systems (MEMS) relay with a contact- force-maximizing structure in a dual-contact material system. A MEMS relay with dual (hard and soft) contact materials is known to have high durability in hot-switching conditions, and the contact force is also considered to be the most important factor that contributes to an efficient reduction of the contact resistance. We devised a contact-force-maximizing structure with a plate-type suspended structure and in-plate springs and applied it to a dual-contact material system to achieve extremely low contact resistance. The fabricated MEMS relay successfully operated sequential switching between the dual contact materials in the contact-force-maximizing structure and thereby showed an extremely low contact resistance of 1.65 $\text{m}\Omega $ with a switching time of $7 {\mu \text {s}}$ at an operating voltage of 80 V. Thanks to the contact-force-maximizing structure with the dual-contact material system, the fabricated MEMS relay achieved a lifetime of up to $1.3\times 10^{\mathbf {3}}$ cycles in the hot-switching conditions of 4 W (10 V/400 mA) in an air atmosphere with a negligible variation of the contact resistance. This power level is the highest reported to date. [2020-0223]