Abstract: A device for dielectrophoretic manipulation of suspended particulate matter comprises a plurality of interleaved layers of electrically conductive and non-conductive material wherein at least one channel is defined through a plurality of the interleaved layers of electrically conductive material.

Abstract: Apparatus for detecting particles in a liquid, comprises an evanescent optical sensor having an electrically conducting layer, and means associated therewith for providing an electric field at or adjacent the sensor surface. Preferably, the optical sensor is a surface bound sensor based on a metal-clad leaky waveguide structure. A DC potential applied to the metal layer and a parallel counter electrode provides a uniform electric field, which drives deposition of the particles on the sensor surface. Alternatively, an alternating potential applied to a electrically conducting layer configured as an electrode and counter electrode induces an electro-osmotic bulk flow in the liquid which drives deposition of the particles on the sensor surface.

Abstract: There is disclosed apparatus for collecting particles from a liquid, comprising a first electrode having an upper surface defining one or more substantially circular areas of a predetermined diameter separated from a counter electrode, having an upper surface bounding at least in part the circular area or areas of the first electrode, by a predetermined gap and means for applying an alternating potential difference of a predetermined magnitude at a predetermined frequency lower than the charge relaxation time of the liquid across the electrodes whereby particles from the liquid are focused onto the circular area or areas of the first electrode through an induced electro-osmotic flow in the liquid.