Microcomputer-based measurement of bubble dielectrophoresis

Publisher Website
Google Scholar
Abstract
An experimental system for the investigation of the dielectrophoresis of bubbles in isomotive electric fields is described. Nitrogen bubbles of radii less than 0.25 mm are injected into transformer oil filling the interelectrode space of the specially shaped electrodes required to generate the isomotive fields. The electrode assembly is aligned so that the effect of increasing the dielectrophoretic force is to reduce the terminal velocity of rising bubbles. A microcomputer, interfaced to an optoelectronic light detector, is used to measure the transit times of bubbles between a triple light beam arrangement at various applied fields. Details of the measurement procedure are given together with the means used for generating the bubbles. Typical data are presented and their analysis support the present use of the system for the study of bubbles and other types of particles in non-uniform electric fields.