UC Berkeley researchers develop first graphene-based headphones

Alex Zettl/Courtesy

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When UC Berkeley professor of physics Alex Zettl arrives at his lab in the morning, he’s never certain that his research assistants are busy at work.

‘I come in and I’ll see them with earphones in, and I’ll ask, ‘What are you doing?’, and they will say, ‘I’m just testing the graphene earphones.’ But I’m never sure,” Zettl said.

Zettl is the director of the UC Berkeley Center of Integrated Nanomechanical System and is working with postdoctoral researcher Qin Zhou to develop a graphene earphone, which many view as a groundbreaking development in sound technology.

Graphene is just one atom thick but is also the strongest known atomic material, capable of efficiently conducting electricity and, now, possibly producing high-quality, energy-efficient sound.

Zhou and Zettl published their findings March 10 in the Cornell University Library, outlining their success using graphene in the earphone’s diaphragm.

According to Zettle, the diaphragm is the disk of material in the earpiece that vibrates in response to electrical signals.  Graphene is light and durable and can reproduce sound effectively within the entire range of human hearing.

When researchers compared the sound quality of Sennheiser headphones and the graphene earphones, the latter headset was comparable to its top-of-the-line commercial cousins, according to their findings.

Scott Amendola, a well-known Bay Area jazz drummer and musician, said that this could be a game-changer for music.

“The sonic quality of recorded music, mainly pop music, has gone down, generally speaking,” he said “But if the general public has access to much better-sounding speakers and headphones for all devices due to graphene and the affordability of this product, that’s great news.”

The beauty of a graphene diaphragm, Zettl said, is that it eliminates the need for dampers, which are used to depress sound frequencies so that they do not damage the diaphragm. Graphene is tougher than the normal paper and plastic diaphragms used currently and is just as good at conducting sound, he said.

Because most of the energy that goes into a pair of earphones is directed at the dampers, eliminating them allows for a more cost effective and energy-efficient pair of earphones.

Zettl said he believes that this energy efficiency and the abundance of graphene could mean a shift toward high-quality but cheaper music.

“You’ve got earphones — you know what’s it’s about,” Zettle said. “You want good high-quality earphones, you want ones that don’t chew up a lot of energy, you want to run your system for a long time.”

However, a revolution in private music will not happen overnight, said Adrian Freed, research director at the UC Berkeley Center for New Music and Audio Technologies.

“It takes a long time for innovations in materials to make it into products,” Freed said. “Graphene might help get the best of both worlds in terms of cost and quality, but I haven’t seen data suggesting that this will happen very quickly.”

UC Berkeley, which owns the patents to the technology, may face such a hurdle should it choose to develop the proof of concept into a commercial product.

However, for Zettl, it would be well worth the trouble.

“Having technology that originates from the university go commercial is a good thing because it shows the public that tax dollars that go into the university are being put to the use of the public,” he said.

Contact Eoghan Hughes at [email protected].