IC-processed electrostatic synchronous micromotors

Micromotors having rotors with a diameter of 120 μm have been fabricated and driven electrostatically to continuous rotation. These motors are built using processes derived from IC micro-circuit fabrication techniques. Initial tests on the motors show that friction plays a dominant role in their dynamic behavior. Observed rotational speeds have thus far been limited to several hundred rpm, which is a small fraction of what should be achievable if only natural frequency were to limit the response. Experimental starting voltages (60 V at minimum and above 100 V for some structures) are at least an order of magnitude larger than had been expected. Continuous motor motion has been observed for as long as one minute under three-phase bias at 200 V. Observations of reverse as well as forward rotor rotation with respect to the driving fields can be explained in terms of the torque/rotor-angle characteristics and friction for the motors.