Transistor radios smaller than a grain of sand, made using nanotechnology, could in theory lead to faster performing devices, according to researchers in America.
 
John Rogers, a professor of materials science and engineering at the University of Illinois, said that the goal was not to make tiny radios per se, but to develop nanotubes as a higher performing semiconductor. He said that the devices were a way of showcasing a new way of making carbon nanotubes in perfectly aligned rows, much like strands of hair that have been combed flat. These strands are a hundred thousand times smaller than the width of a human hair, and form a thin layer of semiconductor material that can be used in electronics devices and circuits.

Rodgers explained: “We’re interested in nanotubes not because they are small, but because smallness imparts some electronic properties that are very appealing.

“You could make a faster device.”

He said a key to the work is to gain control over what shapes the tubes take and how they are configured. The researchers make the tubes by combining carbon and heat and a catalyst on a special wafer material that makes the tubes line up in an orderly way.

The researchers worked with radio frequency electronics engineers at Northrop Grumman Corp Electronics Systems, Maryland, to build and test the radios which consist of two radio frequency amplifiers, a radio frequency mixer and an audio amplifier, all made from the carbon nanotube materials. Regular-sized headphones plug directly into an output transistor made from the nanotube material. A normal-sized antenna was used.

In one test, the researchers tuned one of the nanotube-transistor radios to a Baltimore radio station and picked up the traffic report.

Rogers said the device could work better and have less distortion than some of the tiniest silicon chip technology used today.

Rodgers concluded: “The radio itself is not interesting, but the fact that we are at a point that we can do things like a radio is a good milestone for us.”