Graphene speaker concept (via University of California)
We often associate graphene with super-powered semiconductors for next generation technology such as CPUs and smaller faster mobile devices. Using the material there is some time off. There is one area graphene is already in use, analog amplifiers. The super material is being adapted for use with audio in new high-powered speakers. Computer science engineers from the University of California (Berkeley) have designed a new speaker, about the size used for headphones, which apparently rival the current top of line headphones found on the market today. Traditional speakers work by using a simple damped-down harmonic oscillator (diaphragm) which vibrates over a range of frequencies (20Hz to 20kHz) to produce constant sound by moving air. The damping engineering is what sets higher-priced speakers apart from the ones you can find in the Dollar store. One of the main drawbacks of making higher-quality speakers is the damping engineering becomes more complex over lower-quality speakers and, as a result, becomes more power inefficient. One of the ways of combating the issue of complex dampening is to use a lighter thinner diaphragm, which is difficult to do as using thinner materials usually become fragile over a limited period of time. The engineers from Berkeley, led by Qin Zhou, have found a simple solution using graphene that omits the use of damping technology all together but maintains the quality of sound produced by higher-end speakers. Their design is simplistic but effective and uses a 30nm thick and 5mm in diameter sheet of graphene film for the speaker’s diaphragm, which is situated between two electrodes that create an electrical field. As the magnetic field oscillates, it vibrates the graphene diaphragm as well which in-turn creates sound. The engineers tested their speakers against a pair of Sennheiser MX-400 headphones and found that their graphene-based design was ‘comparable, if not better’ than the MX-400s. Using the super-material in their design converts almost all the energy supplied to it into sound while at the same time prolonging the lifespan of the speakers themselves (graphene is one of the strongest materials known). It’s not yet known if companies will take advantage of the engineer’s audio design, however it’s a good bet we will see them on store shelves sometime in the near future.
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