The present invention provides a nanostructured device comprising a substrate including nanotroughs therein; and a lipid bilayer suspended on or supported in the substrate. A separation method is also provided comprising the steps of supporting or suspending a lipid bilayer on a substrate; wherein the substrate comprises nanostructures and wherein the lipid bilayer comprises at least one membrane associated biomolecule; and applying a driving force to the lipid bilayer to separate the membrane associated biomolecule from the lipid bilayer and to drive the membrane associated biomolecule into the nanostructures.