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Designing graphene into transparent and lightweight speakers
7/29/2011 |
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Researchers Jyongsik Jang and coworkers from Seoul National University have used inkjet printing and vapour deposition to deposit graphene oxide onto poly(vinylidene fluoride) (PVDF), which is then reduced to create a graphene film. This demonstrates not only a new method for making controlled graphene films, but also a new use for the material: for making a thin transparent loudspeaker.
The speaker system consists of a PVDF thin film sandwiched between two graphene electrodes. When an electrical current from the sound source is applied, the converse piezoelectric effect causes the PDVF film to distort, creating sound waves.
Such a system would be easy to install and usable anywhere where sound is needed, Jang explains. They could even eventually be used as noise cancelling devices by creating anti-noise waves (same amplitude but with inverted phase to the original sound).
Although similar speakers are already available commercially, using PEDOT:PSS electrodes, Jang's new system demonstrates advantages over this existing technology in terms of cost and power consumption. "Graphene is cheaper than other electrodes, such as metals and conducting polymers," he says, "and the graphene-based acoustic actuator does not need expensive high power voltage amplifiers due to low power consumption." Julien Happich |
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