First electrowetting of nanotubes

Researchers from the California Institute of Technology have succeeded in forcing liquid mercury into carbon nanotubes. Their technique could have important applications, including nanolithography, the production of nanowires with unique quantum properties, nano-sized plumbing for the transport of extremely small fluid quantities, and electronic circuitry many times smaller than the smallest in existence today.

Reporting in the December 2 issue of the journal Science, Caltech assistant professor of chemistry Patrick Collier and associate professor of chemical engineering Konstantinos Giapis describe their success in electrowetting carbon nanotubes. By “electrowetting” they mean that the voltage applied to a nanotube immersed in mercury causes the liquid metal to rise into the nanotube by capillary action and cling to the surface of its inner wall.

Besides its potential for fundamental research and commercial applications, Giapis says that the result is an opportunity to set the record straight. “We have found that when measuring the properties of carbon nanotubes in contact with liquid metals, researchers need to take into account that the application of a voltage can result in electrically activated wetting of the nanotube.