Patent ID: 8273242

Claim:
A method for extracting charged molecules from solution comprising: providing a first substrate having an array of pillars on a surface wherein the array of pillars is coated with an insulating coating and the pillars comprise an electrode within the insulating coating and a second substrate having an array of pillars on a surface wherein the array of pillars is coated with an insulating coating and the pillars comprise an electrode within the insulating coating; wherein the surface of the first substrate having an array of pillars is placed in proximity to the surface of the second substrate such that the array of pillars of the first substrate and the array of pillars of the second substrate interdigitate and create a channel between the pillars of the first and second substrate; and wherein the channel between the pillars of the first and second substrate has a dimension that is less than 500 μm, flowing a solution containing charged molecules through the channel under conditions that allow charged molecules to adsorb onto surfaces of the pillars; and applying an electric field across the channel to cause any absorbed charged molecules to de-adsorb from surfaces of the pillars.