Next-generation nanofluidic devices near

CHAMPAIGN, Ill., Sept. 17 (UPI) -- U.S. scientists say they've moved closer to producing next-generation, ultra-efficient nanofluidic devices for drug delivery and nano-manufacturing.

University of Illinois scientists led by Professor Narayana Aluru say by discovering the physical mechanism behind the rapid transport of water in carbon nanotubes, they are a step closer to newer and more efficient nanofluidic nanotubes.

Using molecular dynamics simulations, the researchers showed fast transport can be enhanced by orienting water molecules in a nanotube. "Orientation can give rise to a coupling between the water molecules' rotational and translational motions, resulting in a helical, screw-type motion through the nanotube," said Aluru.

Aluru and graduate student Sony Joseph discovered for very small nanotubes, water molecules fill the nanotube in single-file fashion, and orient in one direction as a result of confinement effects. In larger nanotubes, water molecules are not oriented in any particular direction.

"The molecular mechanism governing the relationship between orientation and flow had not been known," Aluru said. "The coupling occurs between the rotation of one molecule and the translation of its neighboring molecules. This coupling moves water through the nanotube in a helical, screw-like fashion."

Aluru and Joseph detail their findings in the journal Physical Review Letters.