Patent ID: 7651600

Claim:
A concentrating device comprising: at least one microchannel, wherein said microchannel fluidically connects a first fluid reservoir and a second reservoir, and a second end; at least one nanochannel, wherein said nanochannel fluidically connects to said first and said second fluid reservoir by a microchannel and is fluidically connected to at least one additional fluid reservoir; a unit to induce an electric field from said microchannel across said nanochannel by applying a voltage between either a first or second fluid reservoir and at least one said additional fluid reservoir such that an ion depletion zone is formed within said microchannel, which provides an energy barrier to a species of interest; a unit to induce an electric field across said microchannel by applying a voltage between said first and second fluid reservoir; and a unit to induce an electrokinetic flow or pressure driven flow across said microchannel; and a conduit, through which a liquid comprising said species of interest can be made to pass; wherein said microchannel is linked to said nanochannel, and said conduit is linked to said microchannel.