An electrostatic lower stator axial-gap polysilicon wobble motor. II. Fabrication and performance

For pt. I see ibid., vol. 7, no. 1, p. 79-86 (1998). This paper presents the fabrication and first performance characteristics of electrostatically driven axial-gap polysilicon wobble motors. The fabrication is based on a four mask process using polysilicon surface-micromachining techniques. Three twelve-stator-pole wobble motor designs have been realized with rotor radii of 50 and 100 μm. Motors have been operated successfully at driving voltages as low as 6 V at speeds up to 150 rpm. The motor performance is characterized by gear ratio measurements and measuring starting and stopping voltages. Motor lifetimes of several million wobble cycles, comparable to operating times of several hours, have been obtained