Performance of microcontacts tested with a novel MEMS device

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 μm². 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 mΩ and 62.9 mΩ. 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 (πr _c²). 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