Development of a levitated micromotor for application as a gyroscope

A miniature rotating gyroscope is described, in which a 0.5 mm aluminium rotor is levitated, rotated, and constrained by a combination of electromagnetic induction and electrostatic forces generated from a unique planar coil design. Integrated into the planar coil design are the sense electrodes that allow the angular-rate of the device to be measured about two orthogonal axes, and acceleration along the third, producing a multimode inertial sensor. In this paper, the results of electrostatic, rotation, and thermal measurements, together with the finite element and analytical modelling are presented. Excellent agreement is found between the electromagnetic and electrostatic experimental measurements and modelling. A simple viscous drag model is proposed to explain the experimental rotational measurements and its limitations are discussed. (C) 2000 Elsevier Science S.A. All rights reserved.