Last month, Graphenea was enriched by the addition of Professor Alexander Balandin as Scientific Advisor. Professor Balandin, leader of the Nano-Device Laboratory at the University of California Riverside (UCR), is an expert on heat conduction of graphene. His engagement will particularly focus on the development of high thermal conductivity materials using graphene.
Graphenea: Professor Balandin, welcome to team Graphenea.
Balandin: Thank you. I am happy to join the team of the most successful graphene company in Europe as a member of the Board of Scientific Advisors.
Graphenea: Tell us a little about yourself.
Balandin: I received my MS degree in Applied Physics and Mathematics from the Moscow Institute of Physics and Technology, Russia and PhD degree in Electrical Engineering from the University of Notre Dame, USA. Presently, I am University of California Presidential Chair Professor of Electrical Engineering and Founding Chair of Materials Science and Engineering at the University of California – Riverside. My research interests include nanostructures, novel materials and devices with focus on quantum confinement effects not only for electrons but also for phonons - quanta of crystal lattice vibrations that carry heat. Phonon thermal transport at nanoscale is presently an important issue owing to the problems of heat dissipation in modern electronic and optoelectronic devices. Phonon transport in graphene is one of my favorite research areas that combine interesting physics and practical engineering applications. In addition to phonons and graphene, my research group investigates other two dimensional materials, and works on creating prototype sensors, transistors and other devices.
Graphenea: How does graphene compare to other materials, in terms of heat conduction?
Balandin: The main heat carriers in graphene near room temperature are acoustic phonons. The physics of acoustic phonon transport in graphene is very much different from that in bulk crystals. The differences of phonon transport originate from two-dimensional nature of this material. In some sense, these differences are as drastic as those for electron transport. In 2008, we discovered that the phonon thermal conductivity of suspended graphene can be exceptionally high exceeding that of the basal graphite planes (~2000 W/mK) for larger samples. We explained it theoretically by the anomalously long mean free path of the low-frequency acoustic phonons in graphene. The few-layer graphene flakes can preserve the heat conduction properties better than other materials. Graphene flakes couple well to other materials which makes them promising fillers for composites.
For those who are interested in technical details I would recommend my review paper A.A. Balandin, "Thermal properties of graphene and nanostructured carbon materials," Nature Materials, 10, 569 - 581 (2011).
Graphenea: What applications do you foresee for graphene in this direction?
Balandin: Specific examples of thermal applications of graphene that we are currently working on include graphene-enhanced thermal interface materials (also referred to thermal pastes), thermal phase change materials (used for Li-ion and other battery packs), few-layer graphene heat spreaders for high power-density electronics and various graphene laminate coatings. Our recent work on graphene laminate coatings attracted interest from industry.
Graphenea: Are you aware of any commercially available products that use graphene for thermal applications? How do those work, and where do you think they could be improved?
Balandin: There are some commercially available products out there that claim to incorporate graphene oxide into thermal pastes. We are not sure how much graphene is in those products and are currently investigating some of them. Other companies, e.g. Quantum Seed are developing TIMs with the aligned graphene fillers.
Graphenea: What do you think are the main hurdles that you and Graphenea will face?
Balandin: Like for many other companies that entered graphene research and development efforts finding the “killer” application at least for one of its products in a reasonable time will be the main hurdle. I believe that Graphenea is well positioned to deliver. Graphenea can become materials supplier for other companies that develop specific thermal applications.
Graphenea: Professor Balandin, thank you for your time. We are eager to bring to our readers the fruit of this collaboration in years to come.
Balandin: Thank you.