Researchers Unzip Carbon Nanotubes to Make Ribbons of Graphene

A new route to the narrow graphene ribbons needed in electronics

3 min read

16 April 2009—Graphene, a one-atom-thick sheet of carbon with remarkable electrical properties, shows promise for future generations of high-speed transistors. It may have uses as diverse as the production of sensors or as scaffolding for tissue regeneration. But research is still in the early stages, in part because it’s so difficult to produce large quantities of graphene.

Now two research groups are reporting ways to make graphene ribbons, ranging in width from a few nanometers to a few hundred nanometers. The width matters because it, along with the shape of the edges of the ribbons, affects the conductivity of the graphene; ribbons narrower than about 10 nm confine the movement of electrons and act as semiconductors, while wider ribbons act as metallic conductors. Both methods start with carbon nanotubes and ”unzip” them to form flat ribbons of graphene.

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A Circuit to Boost Battery Life

Digital low-dropout voltage regulators will save time, money, and power

11 min read
Image of a battery held sideways by pliers on each side.
Edmon de Haro

YOU'VE PROBABLY PLAYED hundreds, maybe thousands, of videos on your smartphone. But have you ever thought about what happens when you press “play”?

The instant you touch that little triangle, many things happen at once. In microseconds, idle compute cores on your phone's processor spring to life. As they do so, their voltages and clock frequencies shoot up to ensure that the video decompresses and displays without delay. Meanwhile, other cores, running tasks in the background, throttle down. Charge surges into the active cores' millions of transistors and slows to a trickle in the newly idled ones.

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