A RESONANT, DIELECTRIC MICRO-MOTOR DRIVEN BY LOW AC-VOLTAGES (LESS-THAN-6V)

An asynchronous, dielectric micro-motor consisting of an AL-SiO2 rotor of 50 to 200 mu m diameter was driven with 4 or 8 circularly arranged electrodes in water. The motor elements were fabricated by micromachi ning. Each electrode was designed to be an oscillatory circuit with a sharp resonance frequency in the upper kHz-range. The resonances at al l electrode tips increase the voltage in the stater-rotor gap by a fac tor of up to 15. As a result, the dielectric rotor operates in a sharp frequency window at 5 V-pp excitation as if driven with more than 75 V-pp. With square wave pulses, the higher order Fourier-components ind uce several changes in rotor spin direction within two frequency decad es. The micro-motor has been driven for hours without noticeable wear. It developed high starting torques and was useful for circular water pumping. The system has the advantage of very sensitive frequency depe ndence and the low drive voltages (below 10 V) can be produced by most electronic circuits.