Pumping based on transverse electrokinetic effects

This work presents a strategy for microfluidic pumping based on transverse electro-osmotic flow in a channel with topographical features on one wall. In this channel, flow along the long axis is generated by an electric field applied across the channel. The pump operates at low (5–10 V) voltage and achieves pumping speeds up to ∼100 μm/s in submillimeter channels. The pump is straightforward to fabricate, contains no moving parts, and provides local control of the direction and strength of pumping. The performance of the pump scales favorably with decreasing size of a microchannel.