Select your localized edition:

Close ×

More Ways to Connect

Discover one of our 28 local entrepreneurial communities »

Be the first to know as we launch in new countries and markets around the globe.

Interested in bringing MIT Technology Review to your local market?

MIT Technology ReviewMIT Technology Review - logo


Unsupported browser: Your browser does not meet modern web standards. See how it scores »

{ action.text }

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. (See “A Breakthrough in Nanotube Transistors.”) By way of demonstration of the ability to use the method in electronics, he has made a radio receiver out of which each of the active components is created from nanotubes. To test the electronics, the researchers say that they tuned the nanotube radio to a commercial station in Baltimore to hear the traffic report.

“It’s a very significant advance,” says Peter Burke, head of the nanotechnology group at the University of California, Irvine. “They have been able to make the first radio-frequency amplifier out of nanotubes.”

Indeed, 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.

Rogers says that the fabrication method used to build the analog lends itself to current manufacturing processes. “With these arrays, we can build our devices, device arrays, and integrated circuits in wafer scale processing sequences that are fully compatible with established approaches to building semiconductor devices,” says Rogers.

A crucial factor in making these transistors lies in Rogers’s ability to grow the carbon nanotubes in such uniform arrays. But by growing the nanotubes on a single crystalline quartz substrate, using a standard chemical vapor deposition process, Rogers and his coworkers were able to fabricate “aligned arrays that are completely parallel,” he says.

0 comments about this story. Start the discussion »

Credit: John Rogers, UIUC

Tagged: Computing, Materials, nanotubes, radio

Reprints and Permissions | Send feedback to the editor

From the Archives


Introducing MIT Technology Review Insider.

Already a Magazine subscriber?

You're automatically an Insider. It's easy to activate or upgrade your account.

Activate Your Account

Become an Insider

It's the new way to subscribe. Get even more of the tech news, research, and discoveries you crave.

Sign Up

Learn More

Find out why MIT Technology Review Insider is for you and explore your options.

Show Me