Disclosed are microfluidic devices and systems for the desalination of water. The devices and systems can include an electrode configured to generate an electric field gradient in proximity to an intersection formed by the divergence of two microfluidic channels from an inlet channel. Under an applied bias and in the presence of a pressure driven flow of saltwater, the electric field gradient can preferentially direct ions in saltwater into one of the diverging microfluidic channels, while desalted water flows into second diverging channel. Also provided are methods of using the devices and systems described herein to decrease the salinity of water.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with Government Support under Agreement DE-FG02-06ER15758 awarded by the U.S. Department of Energy, and Contract EP-D-12-026 awarded by the U.S. Environmental Protection Agency. The Government has certain rights in the invention.