Dielectrophoretic Membrane Filtration Process by Integrating Microelectrode Array

Abstract

A coupled AC dielectrophoretic membrane filtration technique is proposed in this paper.This technique utilizes ACdielectrophoresis and preferential transport through a semi-permeable membrane. Simultaneous application of ACdielectrophoresis and membrane filtration can be used for separation of trace amounts of a target species from an emulsion. This can be achieved by embedding inter-digitated microelectrode arrays on a membrane surface used in a cross flow filtration system. The electrode array, when actuated by an AC signal, will create a dielectrophoretic force field to capture the target species onto the membrane surface from the flowing emulsion during cross flow filtration. This paper explains the theoretical principles underlying such a process, and describes a simple mathematical framework based on trajectory analysis for assessing the separation efficiency of the technique. Simulation results indicate that preferential transport of the emulsified water through themembrane in a cross flow filtration device can be significantly enhanced by incorporating an AC dielectrophoretic field in the process. The novel technique proposed here can lead to a highly efficient continuous separation process for dilute emulsions.