Teeny Tiny Tunes

Nov. 16, 2007

Researchers create single carbon nanotube that operates as a fully functional radio.

It's got to be Guinness Book world record. A team of researchers has created a working radio from a single carbon nanotube that they say functions across a bandwidth widely used for commercial radio. Its application possibilities range from radio-controlled devices that could flow in the human bloodstream to a new generation of wireless communication devices.

"This breakthrough is a perfect example of how the unique behavior of matter in the nanoworld enables startling new technologies," says Bruce Kramer, a senior advisor for the National Science Foundation (NSF). The radio was developed at the NSF's Center of Integrated Nanomechanical Systems.

This image, taken by a transmission electron microscope, shows a single carbon nanotube protruding from an electrode. This nanotube is less than one micron long and only 10 nanometers wide, or 10,000 times thinner than the width of a single human hair.The entire radio would easily fit inside a living cell, according to physicist Alex Zettl, a University of California at Berkeley researcher who led the team. The carbon nanotube radio consists of an individual carbon fiber glued to a negatively-charged base of tungsten that acts as a cathode. About one-millionth of a meter directly across from the base is a positively charged piece of copper that acts as an anode. Power in the form of streaming electrons travels from an attached battery through the cathode, into the nanotube, and across a vacuum to the anode via a field-emission tunneling process, according to the NSF.

See Also