- Associated Press - Wednesday, December 13, 2017

LARAMIE, Wyo. (AP) - Coal-based electronics might sound like a science fiction invention, but they are a very real focus of investigation for a handful of researchers at the University of Wyoming.

Their research is one part of a much larger effort at UW to find new uses for coal.

Encompassing several overlapping projects across campus, the Carbon Engineering Initiative is funded by a $2 million appropriation from the State Legislature.

“What we’re trying to do is identify non-energy and non-fuel products that we can make from coal,” said Richard Horner, deputy director of emerging projects and technology for UW’s School of Energy Resources, which manages the initiative. “The focus, therefore, being to make new markets for Wyoming coal.”

While some UW researchers are working on transforming amorphous coal into more ordered or useful carbon materials - such as graphene or carbon nanotubes - others are taking those creations and exploring possible applications for them.

Assistant professor Bill Rice and the researchers in his spectroscopy lab are hoping to make coal-based electronics a reality, by replacing some of the conductive materials in smartphones with carbon - in the form of graphene - derived from Wyoming-mined coal.

“People have used carbon from other sources to demonstrate some of these technologies,” Rice said. “We’re trying to use coal because it’s a cheap carbon feedstock. Now, the problem with coal is it’s dirty, it’s amorphous, it’s hard to work with. But by cleaning it, we can get to the same carbon purities as others.”

Most touchscreens sense when and where they are touched because something with an electrical charge - such as a human finger - interrupts or alters the flow of electricity perpetually running through the screen’s conductive coating.

“The touch screen on your phone is basically an interlocking array of transparent, conductive lines,” said Joe Murphy, a post-doctoral fellow in Rice’s spectroscopy lab.

This conductive coating is generally made out of indium tin oxide, an expensive and environmentally hazardous material. Scientists have discovered ways of replacing this material with graphene and UW researchers are experimenting with this in the lab, using for the first time Wyoming coal as the source of the carbon.

“We start out with an insulating film of graphene oxide and by patterning it with a high-intensity pulse laser, we can cause regions that we pattern to become conductive,” Murphy said. “Basically, we’re drawing on transparent circuits in our already transparent film.”

The cost of graphene generally makes carbon-based circuits like these prohibitive as it cannot compete with the relatively low cost of indium tin oxide. This is because graphene is generally derived from graphite, which is cleaner and easier to work with than coal, but more expensive.

“Using the dirtier source is going to be better because it’s more abundant and it’s cheaper,” Rice said. “Doing that in a cost-effective manner - going from dirty coal to interesting technologically relevant electronics is the hard part.”

A more ambitious, long-term possibility involves replacing other expensive parts of a smartphone with carbon, and specifically carbon derived from coal.

Copper, for instance, is heavier, pricier and rarer than coal, but is an efficient conductor present in many advanced technologies. Carbon, on the other hand, has only been shown to conduct across short distances, Rice said.

“The challenge is, if it can do that over short distances, can we extend that to longer distances, because then we can begin to replace all the wires with carbon instead of copper,” he said. “That’s the dream. That’s not close right now, maybe 20-50 years away. But over short distances, we can demonstrate that carbon can work as well as copper, which is a big advance.”

Developing coal-based smartphone tech is just one of many projects connected to the Carbon Engineering Initiative.

The initiative invests in projects with both near-term and long-term goals, as well as both lower-volume, high-value projects and high-volume, lower-value projects. Some projects are riskier and have a smaller chance of succeeding, while others are more surefire bets.

“Through the School of Energy Resources, they then had experts re-evaluate each of those proposals after one year and they reallocated money to say which projects were moving forward and who can justify this,” Rice said. “So, this was a smart way of applying money.”

The initiative’s goal is to diversify Wyoming’s economy by patenting both useful procedures - such as methods for growing graphene from coal - and products made possible by those methods.

UW would own these patents and grant other entities the rights of use on a royalty fee basis, Horner said.

“To encourage investment in technology development, the patents will be held in a portfolio and available to stakeholders to further commercialize,” he said. “In other words, potential users will be able to negotiate exclusivity and capture apparent synergies between patents, notably to augment their own technology.”

The School of Energy Resources also provided seed money for projects now being funded federally. No longer managed under the Carbon Engineering Initiative, one of Rice’s projects exemplifies the initiative’s ability to attract research monies from outside sources, by serving as a kind of project proving ground.

In Rice’s spectroscopy lab, he and other researchers are teaming with NASA on a project originally supported by the initiative which could improve the safety of air- and spacecraft.

Ice frozen on airplane wings can change flight characteristics, so it would be helpful to use icephobic materials in designing aircraft, said Sam Pasco, a master’s student working in the lab.

“It’s really important to have a good idea of what the ice is going to do to stuff and it’s hard to determine that, so they want to just have stuff that ice doesn’t stick to, period. That would be the easiest thing,” he said. “But it’s hard to make materials like that because we don’t know the exact mechanism and we don’t know how to design for that, really.”

Pasco added current techniques of testing ice adhesion could use improvement.

“They’ll grow ice on something and push it off, and how hard they had to push to push it off, is how they measure the adhesion strength,” he said. “That’s a destructive way to do it and it’s not very consistent. It’s really dependent on a lot of things, so the thing we’re trying to do is develop an optical method.”

An optical method would involve shooting lasers at some material, recording the wavelength of the light that bounces off, using the wavelength to assess the vibrational frequency of the material, then correlating that frequency with adhesion strength.

When the researchers know how frequency and adhesion strength are correlated, they are hoping to be able to measure how well ice sticks to a material by simply shooting a laser at it.

Not knowing what they will find, the researchers are testing materials such as aluminum, carbon fiber, silicon - and graphene.

“We don’t really think any of these things will be icephobic, but it would give us sort of a marker for developing this method,” Pasco said. “Then once we do that, we’re going to try to find materials that are good for that. Maybe graphene would work well for that.”


Information from: Laramie Boomerang, http://www.laramieboomerang.com



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