A New Era of High Fidelity Sound
By Russell McMahon, Marketing Director
You may be familiar with the new revolutionary ‘wonder material’ named Graphene. Created in 2005 at the University of Manchester, it’s made up of pure carbon atoms by chemically processing graphite and it is one to the strongest materials known to man, with 300 times the breaking point of steel. It’s so strong that it’s calculated you could support an elephant on a sheet as thin as cling film. It is also extremely lightweight - a 1 atom thick sheet 1-square-metre in size weighs just 0.77mg. Some physicists regard it as one of the most important substances to be created since synthetic plastics over 100 years ago. Graphene has many theoretically potential uses; wallpaper thin televisions, super capacitors (batteries), it could replace silicon as the raw material for computer chips, and bendy Harry Potter like newspapers to name a few.
Now researchers at the University of Berkeley California, Qin Zhou and Alex Zettl, have been looking in to the applications of graphene to audio technology and have created the world’s first electrostatically-driven speaker - an earphone. They have replaced conventional diaphragms with sheets of graphene 30nm thick and 7mm wide in earphones. The new speaker is simple. It consists of a graphene diaphragm sandwiched between a couple of electrodes that create an electrical field. When this field oscillates, it causes the the graphene to vibrate too and this generates sound. Because speakers typically work best with lightweight and high stiffness to mass materials for a diaphragm graphene is ideal, “It is electrically conducting, has extremely small mass density, and can be configured to have very small effective spring constant” say Zhou and Zettl.
The extraordinary thing is that the new graphene speakers outperform conventional speakers without any tweaks to the acoustic design, “The graphene speaker, with almost no specialized acoustic design, performs comparably to a high quality commercial headset.”
Most of the current diaphragms used in audio need to be ‘damped’ in order to broaden the frequencies in which they perform and prevent them from ripping to shreds. One way to reduce the amount of damping engineering required is to make the diaphragm very thin and light with a small spring constant so that the air itself damps its motion which is difficult due to the weakness of materials as they become thin. Since graphene is both solid and strong it doesn’t need to be damped. Finally, the new speakers also transform most of their energy in to sound so they are incredibly energy efficient.
So what does this mean for the future of audio speakers? Graphene being tipped as the next ‘gold standard’ in the industry. At the moment this ‘wonder material’ is very much still in the research & development stage but its future is looking promising with big grants funding the research. The material itself isn’t exactly cheap right now, but in time it is more than likely that it will be mass produced and affordable to the consumer market. This will presents the opportunity to build even bigger and more powerful soundsystems with insane levels of sound clarity, theoretically. For us, it essentially enables us to enjoy our music even more. Winning.