Gold Coated Carbon-Nanotube Surfaces as Low Force Electrical Contacts for MEMS Devices: Part II, Fine Transfer Mechanisms

Material transfer in switching contacts is considered at very low currents, (below 20mA). The transfer process is critical to a wide range of electronic switching technologies and is a limiting factor for MEMs relays. A test system is described and characterized for bench-marking surfaces. This is followed by a study of Multi-walled CNT´s (MWCNT´s), synthesized on a silicon planar and sputter coated with a gold film. The planar surfaces are mounted on the tip of a piezo-electric actuator and mated with a Au coated hemispherical surface. The switching contacts are tested under conditions typical of MEMS relay applications; 4V, 1mA; with a static contact force of 1mN, results are presented on the bounce process and on the opening characteristic with respect to the melting and boiling voltages for the materials tested.