Active feedback‐controlled dielectrophoretic levitation

摘要

Dielectrophoretic levitation of small metallic particles in insulating dielectric liquids is achieved using a microprocessor‐controlled digital feedback system. An optical detector senses vertical particle position and the error signal generated controls the voltage applied to the electrodes of the levitator cell. Experiments with single particles confirm a theoretical expression for the axial profile of the electric field. The method of images is used to calculate the effective dipole moments for chains of conducting particles. Experimental levitation data obtained using two‐ and three‐particle chains provide preliminary confirmation for these effective dipole moment expressions.