The stainless-steel cylinder gleams like a shiny tree trunk in the lab of physicist Paul Thibado, vacuum-sealed arms branching out sideways to give him control of what's known as a scanning tunneling microscope.
It's a strong but sensitive technology, nestled in a lab on the bottom floor of the Physics Research Building at the University of Arkansas at Fayetteville. Its position close to the ground makes it less likely for vibrations to rattle the device, built with more than $700,000 in grant money from the National Science Foundation.
But precautions don't stop there. The microscope is supported by a special table that senses tiny vibrations from someone walking by and adjusts to keep things still, an important feature when researching insights at the atomic level.
Lately, the device, which can be used to obtain images of surfaces down to the atomic level, has been focused on graphene, the darling of the materials-science world.
An offshoot of the common mineral graphite, graphene is graphite rendered to the flatness of a single layer of atoms -- a thinness scientists once thought fundamentally impossible.
The material has also challenged the imagination in other ways, with researchers worldwide seeking to harness its properties. Graphene is phenomenally strong, for one, made up of carbon atoms tied to each other.
"It's all these carbon double bonds, and they're just the strongest bonds that we know of on earth," Thibado said. Diamonds, for example, also are made up of similarly bonded carbon atoms, albeit arranged differently.
Other properties also stand out for physicists. Graphene is a conductor with an ability to transfer electrons so rapidly it could lead to developing much faster computers and electronic devices. But it lacks the properties of a semiconductor like the silicon used by makers of computer chips to make it easy to control current, a key for computing applications.
"It has a large number of applications, or at least potential applications," Thibado said.
Thibado's UA team alone has tallied more than a dozen articles on graphene in the past four years.
The material's discovery in 2004 led to a Nobel Prize in physics just six years later, an uncharacteristically short time to bestow such an honor after a physics discovery. The award went to Andre Geim and Konstantin Novoselov, both at the University of Manchester in the United Kingdom.
Thibado recalled first hearing about graphene while talking about five years ago with a former colleague from the U.S. Naval Research Laboratory.
"He was sharing with me his excitement about this new material," Thibado said. The scanning tunneling microscope had been in place at UA for a few years, and Thibado, who joined the UA faculty in 1996, was ready for his research to shift gears, he said.
"I was kind of running out of the good projects, to some extent," Thibado said.
'I'm a surface scientist'
His work has been tied to the scanning tunneling microscope since he was in graduate school at the University of Pennsylvania. Given his background, the allure of graphene was plain to Thibado.
"The interesting thing about graphene is, it's all surface, there's no bulk," Thibado said. "And I'm a surface scientist."
Other scientists have also been attracted to graphene. In 2005, physicists who gathered for the annual American Physical Society meeting on condensed matter -- "anything you can touch or feel," as James Riordon, spokesman for the group, put it -- saw peers give 19 presentations about graphene. Five years ago, there were 364 presentations. At the most recent event this year, that number nearly doubled to 697 presentations, including five by Thibado's team, Riordon said.
"It doesn't show any signs of slowing," he said of the surge in research into graphene.
Thibado said there are a large number of fundamental physics experiments that can only be done with graphene "that could never have been done before on any other material system."
Some of his team's work has sought to explain fundamental questions about graphene.
"It's still a research topic, really, why does graphene exist at all?" Thibado said.
Filing a patent
Theories advanced in the 1920s suggested that materials would be unstable at a thickness of about 50 atomic planes. Graphene is so thin it's transparent, but it doesn't need to be kept at a special temperature to exist.
At the atomic level, however, it's not completely smooth at the surface. Thibado's team found this can help keep the material together.
"Basically, the bending of the carbon bonds coupled to the stretching of the carbon bonds makes the structure more rigid and less capable of falling apart," Thibado said.
Another research topic has potentially a more direct application to technology. Thibado's team has deposited platinum on top of graphene, perhaps creating a building block for a cheaper, more efficient hydrogen fuel cell.
Thibado said fuel-cell applications in cars, for example, are limited because of the cost of platinum. But the technique developed involving graphene uses less platinum and also allows for it to be used more efficiently, he said.
"The university's filing a patent on this," Thibado said.
Touch-screen prospects
Looking at graphene more broadly, Thibado said he suspects that it will be "very far in the future" before it replaces silicon in typical computer applications.
However, because graphene is flexible and durable, it may be used soon in touch screens for devices such as smartphones and tablets, as well as wearable devices.
"You can make displays as big as you want, and they're flexible, so you can have them be any kind of shape you want. And they're cheaper," Thibado said.
His team, which includes a postdoctoral researcher, Peng Xu, has grown over the years. Another UA physicist, Salvador Barraza-Lopez, with UA mathematician Edmund Harriss and other collaborators recently had a paper published that used mathematics to describe graphene. Thibado's group has collaborated not only with other UA physicists but also with researchers in Belgium, among other places.
"There's still some fundamental issues that are out there left to be uncovered," Thibado said.
Metro on 06/01/2014