Fine transfer in electrical switching contacts using gold coated carbon-nanotubes

To improve the switching performance of MEMS relays, carbon nanotubes (CNTs) have been used to provide a compliant layer on switching contacts. In this study a Gold coated CNT composite surface synthesized on a silicon wafer, was mounted on the tip of a piezo-electric actuator and mated with a Au coated hemispherical surface. The switching contacts were tested under conditions typical of MEMS relay applications; 4V, 1-20 mA; with a static contact force 1 mN. The switching characteristics of the surfaces are investigated, with particular focus given to the opening and closing voltage transients. At opening, to evaluate the thermodynamic process associated with the contact interface known as molten metal transfer; and at closing to evaluate the bounce characteristics.