Integrated magnetic microrelays: normally open, normally closed, and multi-pole devices

A fully integrated magnetically actuated micromachined relay has been realized. This particular device uses a single layer coil to actuate a movable upper magnetically responsive platform. The minimum current for actuation was 180 mA, resulting in an actuation power of 33 mW. Devices have been tested which can make and break 1.2 A of current through the relay contacts when the relay is electromagnetically switched. Operational lifetimes in excess of 300,000 operations have been observed. A normally closed relay has also been developed through the addition of permanent magnets to the microrelay. These devices have also been able to electromagnetically switch 1.2 A of current. Multi-pole devices, which contain more than one pair of contacts per coil have also been realized, and possess comparable performance characteristics to single-pole devices