Dielectric induction micromotors - field levitation and torque-frequency characteristics

The characteristic motor operation of miniaturized dielectric induction motors is discussed with respect to microfabrication in semiconductor technology. The influence of a fluid filling the interspace between rotor and stator is explained. Electirc field traps can be produced by appliying a.c. and also rotating electric fields of high frequencies using appropriate electrode geometries. At certain frequencies, negative dielectrophoresis can be used for self-centring of a spherical or disk-shaped rotor in field traps. It is discussed how the resistance to abrasion can be increased by avoiding mechanical bearing elements. Remarks on the design of induction motors arc added.