Latching micromagnetic relays

This paper describes the underlying principles, design and operation of a new type of latching micromagnetic relay. The device is based on preferential magnetization of a soft magnetic cantilever in a permanent external magnetic field. Switching between two stable states is accomplished by momentarily changing the direction of the cantilever´s magnetization by passing a short current pulse through a planar coil situated under the cantilever. Once the relay is switched, it is held in this nonvolatile state by the permanent external magnetic field. Latching operation has been demonstrated for devices having two different cantilever geometries and a variety of sizes. Characterization has been performed under dc and ac conditions. The minimum (lead-to-lead) resistance through the switch is approximately 50 mΩ.. The switching current and minimum switching pulse width are 79 mA and 0.2 ms, respectively. The operating voltage is about 5 V. The switching energy consumption is <9.3 μJ