Graphene is a very strong, thin and light material used in various applications such as integrated circuits, solar cells and ultracapacitors. Composed of pure carbon, the atoms are arranged in a regular hexagonal pattern in sheet form similar to graphite with thickness of one-atom. According to Nokia, graphene is 300 times stronger than steel.
Due to its thin, light and strong nature, researchers from University of California Berkeley, Qin Zhou and Alex Zettl found graphene to be the ideal material for constructing speaker diaphragms.
Ideal speaker diaphragms are thin and light so that air itself damps its motion to produce sound. In essence, the thinner the diaphragm material, the better the sound quality. Due to the fact that most thin materials are fragile, it is a delicate balancing act between producing good sound quality and constructing a durable diaphragm. This is where graphene shines.
In a test, the researchers used a graphene film that is 30nm thick to construct a diaphragm measuring 5mm in diameter. Using the graphene diaphragm, they created a speaker and compared its performance to a Sennheiser MX-400 earphone. The result is promising. “Even without optimization, the speaker is able to produce excellent frequency response across the whole audible region (20 Hz~20 KHz), comparable or superior to performance of conventional-design commercial counterparts,” they say.
With a promising results like this, it will be a matter of time before graphene becomes the dominant material in the earphones market.