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Nanotechnology produces an analog radio made from carbon nanotubes

This nanotech electronic device is not nanoscale, but all of the transistors are made from parallel arrays of thousands of nanotubes to demonstrate the potential of single-walled carbon nanotubes in advanced electronics. A few excerpts from “Tuning in to nanotube radio“, over at Technology Review, written by Duncan Graham-Rowe.

Carbon nanotubes have long been a contender for future electronic devices because of their potential to scale down the size of components and their excellent electronic properties. But building practical circuitry out of carbon nanotubes has proved challenging. Now researchers at the University of Illinois at Urbana-Champaign report having made scalable radio-frequency analog electronics in which all of the transistor-based devices, including the antennas and amplifiers, are built out of nanotube transistors.

The goal is to establish carbon nanotubes as a realistic competitor with conventional analog electronics, says John Rogers, a professor of materials science and engineering at the University of Illinois. Rogers found a novel way to make transistors using parallel arrays of nanotubes.

…other groups have already demonstrated the use of single nanotubes in radio circuits. (See “The World’s Smallest Radio.”) “What we have done is a bit different,” says Rogers. The previous research has involved using a single carbon nanotube to act as a radio receiver. “In our radios, every single active component is based on nanotubes, all the way up to the point where the headphones plug in,” he says.

Employing single nanotubes in this way would not normally be feasible because of the relatively high currents used in analog circuits, such as amplifiers. To get around this, Rogers’s nanotransistors consist of arrays of thousands of nanotubes in parallel, in such a way that they spread the current, while collectively behaving like a semiconductor material.

Professor Rogers’s research group has a news page with a couple dozen links to other news reports on this achievement. Their research was published in the Proceedings of the National Academy of Sciences (abstract) and a PDF is available on the researchers’ web site.
—Jim

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