Patent ID: 8007648

Claim:
A device for electrokinetic transport of an aqueous solute, comprising an electrically insulating substrate; a conductor element for electrokinetic transport of the solute, the conductor element being in the form of a solid hydrophilic-matrix layer on the substrate, the matrix layer being in a substantially dry, inactive state wherein electrokinetic transport is substantially prevented; a pair of spaced apart electrodes in electric contact with the conductor element at spaced apart locations for applying an electric potential across the conductor element; and a cover layer for electrically insulating and encapsulating the conductor element on the substrate, the cover layer being made of an encapsulating material which is water vapour permeable, but impermeable to the solute; whereby exposure of the hydrophilic matrix to water converts the matrix from the inactive state to a hydrated, active state permitting electrokinetic transport of the solute.