Scientists have released new theoretical research that suggests tiny nanoscale antennas made from graphene could overcome the limits of similar antennas fabricated from traditional metal components to enable highly efficient networks of nanomachines.
Graphene, a material comprised of a hexagonal structure of carbon atoms, is capable of generating a type of “electronic surface wave” that would enable antennas measuring only one micron long and 10 to 100 nanometers wide to handle the work of much larger antennas, say researchers from the Georgia Institute of Technology in Atlanta.
“We are exploiting the peculiar propagation of electrons in graphene to make a very small antenna that can radiate at much lower frequencies than classical metallic antennas of the same size,” Ian Akyildiz, a Ken Byers Chair professor in telecommunications in the School of Electrical and Computer Engineering at Georgia Tech, said. “We believe that this is just the beginning of a new networking and communications paradigm based on the use of graphene.”
While the operation of graphene nanoantennas has yet to be demonstrated in an experimental setting, the team believes their simulations prove that the use of graphene in the tiny antennas could enable efficient communication between tiny nano-devices because of a unique difference discovered between graphene-based and metal-based antennas. In order to operate successfully at the micron scale, antennas made from metal would have to operate at frequencies of hundreds of terahertz, say the researchers, which would require a large amount of power and limit transmission range to just a few micrometers due to propagation losses.
Graphene, however, exhibits special properties that would allow nano-antennas made from the material to operate at the low end of the terahertz frequency range—between 0.1 and 10 terahertz— instead of at the 150 terahertz range used by traditional copper antennas at nanoscale sizes, says Akyildiz. Along with his Ph.D. student, Josep Jornet – who graduated in August 2013 and is now an assistant professor at the State University of New York at Buffalo— Akyildiz has studied graphene and how electrons behave in single-layer sheets of the material as part of his work on nanonetworks.
“When electrons in graphene are excited by an incoming electromagnetic wave, for instance, they start moving back and forth,” Akyildiz said of the subatomic particles. “Because of the unique properties of the graphene, this global oscillation of electrical charge results in a confined electromagnetic wave on top of the graphene layer.” Known as surface plasmon polariton (SPP) waves, these electromagnetic waves require less power, making them a feasible option for use with nanomachines.
In addition to the nanoscale antennas, the Georgia Tech researchers are also working on graphene-based nanoscale transceivers and the transmission protocols that would be necessary for communication between nanomachines. These and other nanoscale components could be combined to help full-size cell phones and other wireless devices communicate faster.
The team plans to continue their research by fabricating a graphene nanoantenna and operating it using a graphene transceiver.
