Abstract:
The design and fabrication process of fully self-aligned nickel electrostatic wobble micromotors with stators overhanging above rotor are reported. The micromotors were fabricated using quasi-LIGA technology, in which the electroformed nickel was used as a structural material for stator, rotor and bearing, and electroformed copper as a sacrificial and self-aligned layer to obtain small gaps between movable and stationary parts. In addition, all the key fabrication processes were performed at low temperature. The experimentally obtained gap between rotor and stator, rotor and bearing is 2.5 and 1.3
μm, respectively. The experiments show that the micromotors wobble at a bias of 15V, and rotate continuously at bias of 30~55V. It is found that the rotation speed and gear ratio depend on the frequency and voltage of pulse bias.