Patent ID: 7316769

Claim:
A method of separating molecules of varying length, the method comprising: (a) providing an apparatus that comprises a chamber having a first region that is adjacent to a second region, wherein the first region comprises a lower free-energy than the second region, and wherein the second region comprises a plurality of nanospaced pillars, and a composition comprising molecules of varying lengths in a fluid disposed in said first region; (b) applying a predetermined driving force appropriate to drive specific length molecules from the first region entirely into the second region, and to drive molecules longer than the specific length from the first region partially into the second region; (c) reducing or removing the driving force to cause molecules that are longer than the specific length molecules and that are not driven entirely into the second region during the application of the driving force to recoil back into the first region, thus resulting in the separation of molecules based on length, wherein the first region comprises a sufficiently lower free-energy than the second region such that the step of reducing or removing the driving force alone effects the recoil.