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1997
Journal Article
Titel
A resonant, dielectric micro-motor driven by low ac-voltages
Abstract
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 micromachining. Each electrode was designed to be an oscillatory circuit with a sharp resonance frequency in the upper kHz-range. The resonances at all electrode tips increase the voltage in the stator-rotor gap by a factor of up to 15. As a result, the dielectric rotor operates in a sharp frequency window at 5 Vpp excitation as if driven with more than 75 Vpp. With square wave pulses, the higher order Fourier-components induce several changes in rotor spin direction within two frequency decades. 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 dependence and the low drive voltages (below 10 V) can be produced by most electronic circuits.