Use of combined dielectrophoretic/electrohydrodynamic forces for biosensor enhancement

Dielectrophoretic and electrohydrodynamic forces have been demonstrated in the literature to cause movement of particles across the surface of planar electrodes when exposed to low-frequency (approximate to1 kHz) electric fields. In this paper we describe the development of this phenomenon for collection of particles, covering a range of sizes, out of a liquid and focusing them at the centre of a novel electrode consisting of large interlocking circles. The volume of analyte across which this effect is observed is significantly larger than has been reported for conventional dielectrophoretic arrays. By altering the experimental conditions, particles can either be collected or cycled across the surface and then removed. This technique offers great scope for enhancement of surface-based detection methods.