Dielectrophoretic manipulation of drops for high-speed microfluidic sorting devices

We demonstrate a high-throughput drop sorter for microfluidic devices that uses dielectrophoretic forces. Microelectrodes underneath a polydimethylsiloxane channel produce forces of more than 10 nN on a water drop in an inert oil, resulting in sorting rates greater than 1.6 kHz. We investigate the dependence of such forces on drop size and flow. Alternate designs with electrodes on either side of a symmetric channel Y junction provide refined control over droplet selection.