for National Geographic News
Apple's iPod Nano may be small, but now researchers have made a radio that really deserves the title "nano."
A carbon nanotube—a hollow, tube-shaped molecule 10,000 times smaller than a human hair—can perform all the basic functions of a radio when it's wired up to a few other simple parts, a new study shows.
The simple tube is ten carbon atoms wide and only a few hundred nanometers long.
Alex Zettl and colleagues at the University of California at Berkeley showed that a nanotube can work as an antenna, picking up radio signals from the air.
In the experiment, a nanotube was attached to a copper wire and encased inside a tiny vacuum chamber.
The researchers found the same nanotube can also work as a tuner and pick up a specific channel AM and FM channel. It can also amplify the signals.
Finally, the tube can turn information from the signal into an electric current—like the current that flows through the power cord to your computer—so that sound could be played through speakers or headphones.
"The real breakthrough is to have one nanotube do all these things," Zettl said.
The new findings were published last week in the journal Nano Letters.
Various research groups have made nanotubes that could perform one or another of these functions, Zettl said.
"But we weren't sure how to integrate it all together," he said.
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