Patent ID: 8795498

Claim:
A method of size-exclusion based separation of a bin of particle sizes using a cross-flow system comprising: flowing particles of interest using dielectrophoresis in a cross-flow orientation over a polymer trench network of high aspect ratio hydrogel monoliths attached to a solid surface and patterned in series to form the trench network wherein the trench network is comprised of a reversible binding surface; spacing the high aspect ratio hydrogel monoliths to produce a tunable gap for the size-exclusion based separation wherein the tunable gap is a function of trench wall height, trench wall thickness, and trench width; and adjusting the temperature of the polymer trench network above or below a critical solution temperature to control the opening of the trench network to trap at least one of the particles of interest in the trench network; whereby adjusting the temperature below the critical solution temperature of the polymer used in the polymer trench network closes the network by causing the hydrogel monoliths to swell parallel to the solid surface thus trapping lower scale particles in the trench network and adjusting the temperature above the critical solution temperature of the polymer opens the network releasing the previously trapped particles.