An electrostatic lower stator axial-gap polysilicon wobble motor. I. Design and modeling

This paper presents design issues and a theoretical model of electrostatically driven axial-gap polysilicon wobble motors. The motor design benefits from large axial rotor-to-stator overlap and large gear ratios, and motor designs with rotor radii of 50 and 100 /spl mu/m are capable of generating torques in the nanoNewtonmeter range at high electrostatic fields. Because of the large gear ratio, smaller angular steps and lower rotational speed are obtained, compared to radial-gap motor designs. Aspects like gear ratio, torque generation, excitation schemes and torque coverage, normal forces, friction, rotor kinetics, and dynamical behavior are addressed. The motor design is compliant to the integration of gear linkages with respect to mechanical power transmission.