Researchers at Seoul University have come up with the utmost innovation in sound technology transparent loud speakers, made using Graphene. The team used a special kind of plastic material called Poly Vinylidene Flouride (PVDF), on which a layer of Graphene Oxide was printed’ in order to achieve this.
Graphene is a single layer of carbon (picture above), manufactured by industrial methods like Carbon Vapour Deposition or by simply stripping away at Graphite using Scotch Tape. It is the material, hot and happening, in today’s material science research.
Graphene Oxide was used as the ink. Prepared using known and tested methods, the synthesized Graphene oxide was filled in an empty inkjet printer cartridge. This would be the ink’ for printing on the PVDF.
The PVDF was treated using low oxygen plasma treatment, so that the surface is amiable for printing’.
The technology used for printing was the regular inkjet printer technology. The moment two layers of Graphene oxide were printed’ uniformly on the two sides of the PVDF, the entire material behaved like an electrolyte and the Graphene layer acted as the electrodes. Dipping the printed sheet of PVDF into hydrazine and ammonia solution completed the printing process.
The rest of the process is straight forward. Regular digital pulses of electricity excite the PVDF sheet and due to the piezoelectric effect (or its inverse, if you prefer), the PVDF sheet bends in specific ways so as to produce sound waves.
Where might this be useful?
The applications are immense. Soon, one might have screens with a thin PVDF-Graphene layer, doubling up as the primary speakers on his/her laptop. Giant screens would be their own audio sources. Even the car windshields or windows might double as the entertainment devices. There is also the huge possibility of inducing anti-noise vibrations, making these PVDF speakers perfect for noise reduction.
The good news is that these are extremely inexpensive and quite durable. The bad news is that the sound quality needs a lot to be desired, especially at low scales.
Wonder material Graphene does it again, but there are still chinks to iron out. Graphene is hot, really hot. Is that loud and clear?