A bi-directional electrothermal electromagnetic actuator

A bi-directional microactuator powered by the combination of electrothermal and electromagnetic forces is successfully demonstrated using both the Poly-MUMPs surface micromachining process and a 50 μm SOI process. High output force has been measured from fabricated actuators in both DC and AC operations at non-resonant frequencies. Surface micromachined actuators can move several microns and exert more than 100 μN of force, while the larger SOI actuators can move several tens of microns and exert more than 20 mN of force. Reliability tests show that the SOI and surface machined actuators have been in operation for more than 1 million and 100 million cycles, respectively, with no sign of degradation.