The invention comprises two key components: dielectrophoresis (DEP) and reversible binding surfaces. DEP has become an important tool for trapping dielectric particles. Moreover, DEP can manipulate cell movement as dictated by the intrinsic dielectric constant of the cell without modification. DEP therefore provides a mechanism by which to force targets in a flow channel to a reversible binding surface. By building selectivity into the binding surface, the capacity to choose which targets can be held after the dielectric field is turned off, providing a separation strategy that does not suffer from fouling issues, as large foulants can freely pass over the surface through the flow channel.