Following up my September 12th piece, “CVD Equipment: More Than Just A Pure Play On Graphene,” I interviewed Professor Eric Pop from the University of Illinois Urbana-Champaign. Last spring, Professor Pop’s group made a groundbreaking discovery regarding one of graphene’s many incredible properties. Backed by the support of the Air Force Office of Science and the Office of Naval Research, the group, based in Champaign, discovered that graphene has the ability to self-cool.
My original article about CVD Equipment Corporation was intended to illustrate that the company will not only benefit from the growth of graphene in the consumer market but also from growing research, across multiple disciplines and industries. As CVD sells the “bench-top” equipment needed for this research, they’ll benefit from selling not only the material, but also the tools to explore and expand its uses. My interview with Professor Pop covers both of these issues surrounding CVD Equipment, with an emphasis on the future of graphene.
I would like to thank Professor Pop for his time and insights. Below is a summary of my questions and Professor Pop’s answers.
Q: How soon do you see graphene moving from largely a research material to a component of everyday consumer goods?
A: Maybe even by next year. There has been much discussion (and some technical reports demonstrating feasibility) that Samsung will incorporate graphene into flexible-display cell phones in the near future. (also see my answer to your last question below.)
Q: Is graphene the only material that displays resistive heating? Could such ability to self-cool allow for more energy efficient computing as well as more powerful?
A: Nearly all materials display resistive heating, except superconductors. Resistive heating means that the material heats up when you pass an electric current through it, due to electrons knocking against the atomic lattice, producing vibrations which we perceive as a rise in temperature. In silicon this is what causes our laptops to heat up when we use them. The simple light bulb works by resistive heating a thin tungsten filament until it becomes so hot it glows. Lesser known is that Edison originally considered graphite as a filament material before settling on tungsten.
The ability to self-cool is a very different mechanism from resistive heating. This is based on the Peltier effect, which can lead to cooling or heating depending on the direction of current flow. The Peltier effect for cooling is a bit more similar to how a gas cools when it expands abruptly (think about a can of spray paint). The Peltier effect in transistors and circuits could allow us to “shuttle” the heat around, moving it from regions what are active and hot due to resistive heating (see above) to other regions that could just serve as heat sinks.
Q: How does the price of graphene relate to silicon? Do you see the price of graphene falling as it exits the research world and enters the consumer market?
A: Silicon is the #2 most abundant element on Earth, carbon is the 15th. So graphene may always be a bit more expensive than silicon. However, graphene is a lot more abundant (and cheaper) than almost all other materials used in electronics, such as germanium, copper, or indium. Naturally, the price of graphene-based technologies should drop as these enter the market. For instance in displays graphene would replace conductors based on indium-tin-oxide, so it is possible that the price of graphene-based displays could be lower even from the start.
Q: What interest did the Air Force Office of Scientific Research and the Office of Naval Research have in your study? Does the military see a use for graphene?
A: The military is interested in high-speed, low-power (and light-weight) electronics, and indeed graphene could help with many of these aspects.
Q: What other industries do you believe will benefit from such a material? Solar? Oil?
A: Solar is a clear use, because of graphene as a transparent conductor. Oil it is harder to say, unless you think of oil as a source of carbon to make graphene. Other industries would be for chemical and biological sensing, perhaps medical applications (because it is a conformal, transparent conductor), and to make nanopores for DNA sequencing (because it is less than 1 nanometer thin).
Q: In 2010, the University of Illinois ordered multiple First Nano products from CVD Equipment Corporation. Could you comment on the use of CVD’s equipment in the lab, its effectiveness, and ability to benefit those researching Nano material products and specifically graphene.
A: CVD (chemical vapor deposition) is the most straightforward way to obtain large area films of graphene today, ranging from centimeters to meters. For instance, my research group has been using a small CVD furnace to grow carbon nanotubes since 2007 and graphene since 2009. The same CVD furnace can be used for both, with only minor modifications. Researchers in Korea used a similar method last year to demonstrate roll-to-roll production of graphene sheets up to 30-inches wide, which were transferred directly to flexible, transparent plastics for display applications.
Professor Pop’s answers highlight some important points about both graphene and CVD Equipment. One, graphene may enter the consumer market place far sooner than I, or many, believe either in the form of flexible cellular displays, or electronic microchips. Two, besides solar, the other major industries looking into graphene are medical industries and the military. Finally, CVD (chemical vapor deposition) equipment is a principle business segment of CVD Equipment Corporation likely ensuring demand for CVD’s products as research and consumer markets grow for graphene.
Disclosure: I am long CVV.