AC Dielectrophoretic Filtration of Suspended Particles
Boris Khusid and Yueyang Shen. Chemical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102
Dielectrophoresis is the motion of an object under forces resulting from electric field gradients. The dielectrophoretic filtration technology differs radically from barrier-type mechanical filters. In particular, interception of flowing particles in a mechanical filter occurs when particles, whose size is larger than the filter pore size, are captured within the filtering medium as the fluid stream passes through. Unlike a mechanical filter, particles flowing through a dielectrophoretic filter are attracted towards the electrodes and captured in the filter by the dielectrophoretic force, even though their average size can be substantially smaller than the filter pore size. We report a new, economic, easily scaled up method for the fabrication of dielectrophoretic filters. The concept utilizes winding of metal and plastic meshes. In this design, two metal meshes serving as energized and grounded electrodes are mechanically and electrically separated with a plastic mesh. The proposed technology d allows for a reduction in the applied AC voltage and electric power by employing fine mesh materials. The captivity of an AC dielectrophoretic filter is governed by the mesh size, the particle size and polarizability, the flow rate, the field frequency, and the peak-to-peak voltage.