Move over silicon because graphene, the sheet-like form of carbon found in graphite pencils, may hold the key to smaller and faster electronics.
In a paper published in the journal Advanced Materials, engineers at Ohio State University describe a technique for stamping many graphene sheets onto a substrate at once, and in precise locations. Until now, the scale and precision achieved were unattainable. Previously, researchers could only create tiny graphene devices one at a time, and only on traditional silicon oxide substrates, according to an article on the Ohio State University website.
Nitin Padture, a distinguished professor at the school's Department of Materials Science and Engineering Advanced Materials (pictured here), said Graphene has been dubbed 'the new silicon'.
Graphene sheets are extremely thin, just a few tenths of a nanometer (billionths of a meter) and are densely packed in a honeycomb crystal lattice. The material may also deliver quantum mechanical effects that could enable new kinds of electronics. The article explains:
Researchers have shown that a single sheet, or even a few sheets, of graphene can exhibit special properties. One such property is very high mobility, in which electrons can pass through it very quickly -- a good characteristic for fast electronics. Another is magnetism: magnetic fields could be used to control the spin of graphene electrons, which would enable spin-based electronics, also called spintronics.
In their research, Padture and his team carved graphite into different shapes and then stamped them onto silicon oxide surfaces. Padture explains: "Think of a stack of graphene sheets in graphite as a deck of cards. When you bring it contact with the silicon oxide and pull it away, you can ‘split the deck’ near the point of contact, leaving some layers of graphene behind. What we found through computer simulations was that the graphene surface interacts so strongly with the silicon oxide surface that the chemical bonds between the graphene layers weaken, and the lower layers split off."
During experimentation, Padture and his colleagues were able to create a graphite stamp that output shapes with high-definition features that were ten layers thick, or thicker. They found that the stamp could also be reused on other predetermined locations opening up the potential for mass production.
According to the article, the team hopes to stamp narrow features that are only one or two layers thick, by stamping on materials other than silicon oxide.
Graphene based-chips could potentially boost the clock speed of chips up to 1000 gigahertz, according to MIT researchers.
The Center for Emergent Materials at Ohio State partially funded the research.