Researchers from the University of California-Berkeley have created the first pair of graphene earphones, and they're pretty incredible.
Graphene is a material used in things like integrated circuits, solar cells and ultracapacitors. Made of pure carbon, it is incredibly thin and light but also strong, having about 300 times the strength of steel. Its atoms are arranged in a regular hexagonal pattern in the form of a sheet, much like graphite, and it has the thickness of an atom.
These features are precisely why researchers Qin Zhou and Alex Zetti decided to try it out with audio speakers. And as it turns out, it does a pretty good job.
"The graphene speaker, with almost no specialized acoustic design, performs comparably to a high quality commercial headset," say Zhou and Zetti.
So how does it work? Speakers include diaphragms that act as a harmonic oscillator. Most of these need to be dampened, however, in order to allow for a wider range of frequencies across which they can perform. But "damping engineering" is expensive and complex, and can also result in inefficient power usage. In order to reduce the needed amount of damping, scientists have tried making the diaphragm light and thin so that air acts as a sort of damper. However, these efforts have been obstructed by the weak tendency of thin materials.
In comes graphene.
"It is electrically conducting, has extremely small mass density, and can be configured to have very small effective spring constant," say Zhou and Zetti.
While the extent to which graphene will be used in headphones remains to be seen, the material has already been lionized as "the next big thing." The researchers themselves state that they may be able to expand their methods to create larger speakers. With the new developments in mind, it is likely that graphene will become the material of choice for consumer headphones in the future.