MANHASSET, N.Y. — Ohio State University researchers are developing a technique for mass production of computer chips made from graphene.

Most researchers could only create tiny single graphene devices , and only on traditional silicon oxide substrates.

Also, they couldn't control where they placed the devices on the substrate, and had to connect each device to other electronics for testing.

"We designed the technique to mesh with standard chip-making practices," said Nitin Padture, a professor of materials science and engineering. "The industry has several decades of chip-making technology that we can tap into, if only we could create millions of these graphene structures in precise patterns on predetermined locations, repeatedly.

"This result is a proof-of-concept that we should be able to do just that."

Padture, who is also director of Ohio State's Center for Emergent Materials, said that while graphene has huge potential, "there hasn't been a good process for high-throughput manufacturing into chips."

Graphene is made of carbon atoms arranged in a hexagonal pattern resembling chicken wire. In graphite, the material used in pencils, many flat graphene sheets are stacked together.

"When you write with a pencil, you leave graphene sheets behind on the paper," Padture said. Each sheet is so thin—a few tenths of a nanometer—that researchers think of it as a two-dimensional crystal.

"Think of a stack of graphene sheets in graphite as a deck of cards," Padture said. "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," Padture said.

Researchers have shown that sheets of graphene can exhibit special properties, such as very high mobility and magnetism.

Graphene's properties also change when it touches other materials, which makes it a good candidate material for chemical sensors.

Padture and his Ohio State colleagues carved graphite into different shapes—a field of microscopic pillars, for example —and then stamped the shapes onto silicon oxide surfaces.

The researchers were able to stamp high-definition features that were ten layers thick.'The graphite stamp can be used repeatedly on other predetermined locations on the same or other substrates. Potentially, this would lead to a mass-production method, according to Padture.

Eventually narrow features only one or two layers thick could be stamped on materials other than silicon oxide.

The Ohio State research first appeared in a paper published in the March 26 issue of the journal Advanced Materials.