Got a pencil? There's a good chance the "lead" you're using is made of the world's thinnest substance: graphene.
But graphene isn't just good for writing notes. With excellent electrical conductivity, the form of carbon may someday replace the silicon chips in your favorite electronic devices, making them faster and more efficient.
A team at the University of Arizona is working on just that. The group, alongside researchers at the Massachusetts Institute of Technology and the National Institute for Materials Science in Japan, has taken the first steps in getting around one of the drawbacks of graphene's thinness.
Brian LeRoy, a UA assistant professor of physics who worked on the project, said graphene outdoes silicon in, for one, its ability to conduct electricity.
Electrons move without scattering off other objects on graphene, he said. "That means less heat is generated."
Overheating, which can be a problem as devices shrink in size, can be avoided with graphene. The material allows electrons to move extremely fast, much like light particles.
But being the world's thinnest substance creates several problems, such as trying to isolate a single layer of it. LeRoy said 2004 was the first time a single atomic layer of graphene had been isolated by placing it on a piece of silicon oxide. But silicon oxide isn't the perfect surface for graphene.
"It's a bumpy surface," LeRoy said. "It's got a bunch of impurities and defects in it, so that degrades the electronic properties of graphene."
But another material with similar properties to graphene has yielded results: boron nitride. Boron nitride is atomically flat and won't disrupt graphene's electronic properties, LeRoy said, making it an ideal substance on which to place the graphene. With a hexagonal structure nearly identical to that of graphene, boron nitride was an obvious choice, he said.
The team wasn't the first to put graphene on boron nitride, but it was the first to look at graphene's electron density and atomic structure. The team used a scanning tunneling microscope to investigate graphene's electrical properties. The microscope is a large piece of equipment with a sharp metal tip that can be brought close to the surface of the material being investigated so that electrons can jump from the tip to the surface, LeRoy said.
Silicon chips have been on the market for 50 years, but graphene-chip technology isn't all that far away, LeRoy said. Companies such as Samsung have made large-scale pieces of graphene used in touch-screen prototypes, he said.
Still, this type of technology likely won't hit our laptops and iPods for about 15 years, he said, as companies find ways to get graphene from micron-scale uses to massive pieces.
"One of the biggest problems is the way we make these devices," he said. "(We're) taking Scotch tape and peeling pieces off, and searching for them one by one under a microscope."
It's the difference between extremely tiny pieces that can be viewed only under a microscope and a company like Intel in Chandler that can make 12-inch "wafers."
Theoretical physicist Philippe Jacquod, who also worked on the project, said one possible, intriguing application of the graphene chip might be to consolidate all electronic devices.
"You'd have all your devices smaller and faster," he said. "Your tablet PC, laptop, smartphone, all in one."
Jacquod said he couldn't predict where the graphene chip might show up first, but did say that a number of people believe it will replace standard silicon structures for information technology and communication.
"You have a laptop - within an hour, it gets hot," Jacquod said as an example. "So, if you want to make something smaller, you better find something else."
Victoria Blute is a NASA Space Grant Intern. E-mail her at email@example.com