Performance of microcontacts tested with a novel MEMS device

Abstract

Most practical MEMS actuators generate forces ranging from several micronewrons to one or two millinewtons. In order to explore the feasibility of low-resistance contacts for MEMS relays, we explored the force-resistance relationship for gold-gold microfabricated contacts. The effect of apparent contact area on resistance has also been examined for areas between 10 and 90,000 /spl mu/m/sup 2/. The force/resistance relationship of these fully-microfabricated flat microcontacts correlates well with traditional theory and previous experimental results. The average measured resistance varied between 20.5 m/spl Omega/ and 62.9 m/spl Omega/. Decreasing contact area and contact force lead to higher overall contact resistance. However, reducing the apparent contact area by orders of magnitude only had a marginal effect on the overall contact resistance, even when the apparent contact area was orders of magnitude less than the theoretical actual contact area (/spl pi/r/sub c//sup 2/). Furthermore, the force required for a stable microcontact was determined to be below 0.6 mN and therefore within the force range of a MEMS actuator.