New 'Water Chip' for Energy-Efficient Seawater Desalination

Chemists from the University of Texas at Austin and Germany's University of Marburg have introduced a new method to desalinate seawater - called electrochemically mediated seawater desalination - that consumes less energy and is much simpler than conventional techniques. The method can even run on a store-bought battery. The researchers apply a small voltage of 3.0 volts to a plastic chip filled with seawater, or 'water chip.' The chip contains a microchannel with two branches. At the junction of the channel an embedded electrode neutralizes some of the chloride ions in seawater to create an ion depletion zone that increases the local electric field compared with the rest of the channel. This change in the electric field is sufficient to redirect salts into one branch, allowing desalinated water to pass through the other branch.