A device is provided having a flow passage with at least one surface and at least one electrode pair positioned thereon for effecting fluid flow through the flow passage. When at least one electrode of an electrode pair of the at least one electrode pair is powered, a sheath region is generated in the flow passage, wherein the sheath region has a high electric field relative to the remainder of the flow passage. In an embodiment, one electrode of the electrode pair is separated from the other electrode of the electrode pair by a horizontal, vertical, depth, and/or total distance of about 1 microns.