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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Two Startups Are Bringing Fiber to the Processor

Avicena’s blue microLEDs are the dark horse in a race with Ayar Labs’ laser-based system

5 min read
Diffuse blue light shines from a patterned surface through a ring. A blue cable leads away from it.

Avicena’s microLED chiplets could one day link all the CPUs in a computer cluster together.


If a CPU in Seoul sends a byte of data to a processor in Prague, the information covers most of the distance as light, zipping along with no resistance. But put both those processors on the same motherboard, and they’ll need to communicate over energy-sapping copper, which slow the communication speeds possible within computers. Two Silicon Valley startups, Avicena and Ayar Labs, are doing something about that longstanding limit. If they succeed in their attempts to finally bring optical fiber all the way to the processor, it might not just accelerate computing—it might also remake it.

Both companies are developing fiber-connected chiplets, small chips meant to share a high-bandwidth connection with CPUs and other data-hungry silicon in a shared package. They are each ramping up production in 2023, though it may be a couple of years before we see a computer on the market with either product.

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