Active Micro Motor Bearing

For motions in the micro-world mechanical friction and wear severely limit performance and lifetime. For linear and oscillatory motion, flexure hinges help to overcome this limitation, they are successfully implemented for e.g. linear accelerometers or precision instrumentation. In the case of full rotation at high speed, contact-free support is one of the most promising solutions. Potential applications include gyroscopes, optical choppers, discdrives for data storage and optical scanning for various instruments. Common to all these applications is the requirement of high precision of the rotor position. Therefore purely passive means of levitation such as e.g. paramagnetism, Meissner-Ochsenfeld, flux-pinning, A C bearings, will not suffice. Such systems will often need position sensing and active motion control. These facts motivate the further development of active micro bearings. The first steps in this direction were presented in earlier papers [1]. Here we report on the continuation of these efforts. The main result reported is the contact free suspension and rotation of a rotor of submm dimensions with active bearings.