Contactless manipulation of microparts by AC electric fields

Summary form only given. Small-scale devices for microparts handling employing an AC electric field boundary wave were proposed previously by the authors (1995). These devices, with various novel manipulation features, that instantly generate contactless microparts driving forces through electric field creation, have been designed and produced and experimentally validated. Particles as a special group of microparts have been taken as a substitute. On a thin protecting and insulating film interface above a series of encased and insulated parallel field electrodes, particles become either tribo-electrically or inductively charged through the application of balanced three- or six-phase voltages. The resulting nonuniform traveling field-wave conveys the charged particles perpendicular to the electrodes by repulsive forces in a hopping mode from electrode to electrode. Various particle materials with diameters up to 400 /spl mu/m have been examined; metal, glass, and plastic spheres showed the best performances. The transient charge distribution on particles and on the activated electric device, which is responsible for the particle conveyance, has been statically and dynamically inspected by a modified scanning electron microscope (SEM). Theoretical considerations and simulations underline the experimental findings.