[Image above] Credit: Raffaele Esposito; Flickr CC BY 2.0
There’s a lot of hype surrounding the potential use of graphene in commercially available electronics. We’re living in the age of ultra-fast, handheld super computers. And there’s never been more demand for increasing the speed, efficiency, and lifespan of the precious devices we never leave home without.
(Have you ever accidentally left your smartphone at home and spent the rest of the day completely frazzled and unhinged? Yep. Me too.)
Graphene’s single-layer thickness, toughness, and supreme mechanical and thermal properties make it an ideal choice for developing electronic, optoelectronic, and electromechanical devices and sensors.
But when it comes to commercially viable electronic applications, graphene is complicated and expensive to produce at scale.
Well the tide may be turning, according to recent research from physicists at the University of California, Berkeley, who present a graphene-based wideband microphone and a related ultrasonic radio that can be used for wireless communication with easy-to-scale-up technology.
These wireless ultrasound devices “complement standard radio transmission using electromagnetic waves in areas where radio is impractical, such as underwater, but with far greater fidelity than current ultrasound or sonar devices. They can also be used to communicate through objects, such as steel, that electromagnetic waves can’t penetrate,” according to a Berkeley News article about the study.
“There’s a lot of talk about using graphene in electronics and small nanoscale devices, but they’re all a ways away,” says UC Berkeley physicist Alex Zettl in the Berkeley News article. “The microphone and loudspeaker are some of the closest devices to commercial viability, because we’ve worked out how to make the graphene and mount it, and it’s easy to scale up.”
The physicists at UC Berkeley aren’t the only ones on the brink of developing graphene for practical commercial electronic applications. Recent research from Rice University in Houston, Texas, suggests that 3-D structures of boron nitride—aka ‘white graphene’—could be an effective tunable material to manage heat flow in electronic devices.
“Typically in all electronics, it is highly desired to get heat out of the system as quickly and efficiently as possible,” says Rouzbeh Shahsavari, researcher and assistant professor at the department of materials science and nanoengineering at Rice, in a Rice News article. “One of the drawbacks in electronics, especially when you have layered materials on a substrate, is that heat moves very quickly in one direction, along a conductive plane, but not so good from layer to layer. Multiple stacked graphene layers is a good example of this.”
This type of 3-D thermal management system can “open up opportunities for thermal switches, or thermal rectifiers, where the heat flowing in one direction can be different than the reverse direction,” says Shahsavari.
For example, as Shahsavari explains, this can be done by changing the shape of the material or changing its mass. “… Say one side is heavier than the other… The heat would always prefer to go one way, but in the reverse direction it would be slower.”
The UC Berkeley paper, published in the Proceedings of the National Academy of Sciences of the United States, is “Graphene electrostatic microphone and ultrasonic radio” (DOI: 10.1073/pnas.1505800112).
The Rice University paper, published in Applied Materials and Interfaces, is “Dimensional crossover of thermal transport in hybrid boron nitride nanostructures” (DOI: 10.1021/acsami.5b03967).
Materials scientists and engineers: how do you see graphene being adapted for commercial use in electronics and beyond in the next ten years? Share your thoughts with us!