Patent ID: 7163611

Claim:
A system for selectively concentrating an agent within a fluid medium, said system comprising: a first traveling wave grid having (i) a first substrate, (ii) a first plurality of closely spaced and parallel electrically conductive electrodes extending across said first substrate, and (iii) a first plurality of buses providing electrical communication with said first plurality of electrodes; a second traveling wave grid having (i) a second substrate, (ii) a second plurality of closely spaced and parallel electrically conductive electrodes extending across said second substrate, and (iii) a second plurality of buses providing electrical communication with said second plurality of electrodes, wherein the plane of the second grid is oriented at an angle of from 10° to 170° with respect to the first grid; an effective amount of a fluid medium adapted to accommodate said agent undergoing migration therein, said fluid medium in contact with at least a portion of said first plurality of electrodes and at least a portion of said second plurality of electrodes; at least one voltage controller providing a multi-phase electrical control signal to said first plurality of buses, said first plurality of electrodes, said second plurality of buses, and said second plurality of electrodes, wherein said voltage controller is configured to apply said control signal to said first traveling wave grid and said second traveling wave grid such that said agent migrates through said fluid medium at least partially across said first traveling wave grid in a direction generally perpendicular to the direction of said first plurality of electrodes, and then further migrates through said fluid medium at least partially across said second traveling wave grid in a direction generally perpendicular to the direction of said second plurality of electrodes.