Development of a levitated micromotor for application as a gyroscope

A miniature rotating gyroscope is described, in which a 0.5 mm aluminium ro tor is levitated, rotated, and constrained by a combination of electromagne tic induction and electrostatic forces generated from a unique planar coil design. Integrated into the planar coil design are the sense electrodes tha t allow the angular-rate of the device to be measured about two orthogonal axes, and acceleration along the third, producing a multimode inertial sens or. In this paper, the results of electrostatic, rotation, and thermal meas urements, together with the finite element and analytical modelling are pre sented. Excellent agreement is found between the electromagnetic and electr ostatic experimental measurements and modelling. A simple viscous drag mode l is proposed to explain the experimental rotational measurements and its l imitations are discussed. (C) 2000 Elsevier Science S.A. All rights reserve d.