March 22, 2010

Tiny New Desalination Chip Revealed

A new tiny, potentially battery powered desalination device could lead to greater access to drinking water in drought and disaster areas, a group of MIT scientists are claiming.

A group of researchers from the Department of Electrical Engineering and Computer Science at Massachusetts Institute of Technology (MIT), lead by associate professor Jongyoon Han, have devised a chip that is less than an inch in size and can remove salt from sea water using ion concentration polarization.

The device would move charged particles in the water through an ion-selective membrane, pushing salt to the side and making the water suitable for drinking. The unit has successfully completed a proof-of-concept test and successfully converted 50-percent of the saltwater used for the test into drinkable water, removing 99-percent of the salt in the process.

According to Han, the chip can only remove the salt from a small amount of water at a time.

"The idea toward the real-world application is that we would make many of these devices, thousands or tens of thousands of them, on a plate, and operate them in parallel, in the same way semiconductor manufacturers are building many small electronic chips on a single large wafer," Han told the AFP in an email interview, which was published as part of a March 21 article.

"That would bring the flow rate up to around 100 milliliters (three fluid ounces) per minute level," he added, "which is comparable to typical household water purifiers and therefore useful in many applications."

The findings have been published in the journal Nature Nanotechnology, and were made public one day prior to the United Nation's annual World Water Day. The theme of the 2010 event is "Clean Water for a Healthy World."


On the Net: