How would you like a transparent loudspeaker that you can stick on your window, or on your computer screen? You would? According to the Royal Society of Chemistry, a Korean research team has constructed just such a thing, using nothing more complicated that an inkjet printer, graphite flakes and a little vapour deposition. So get in line for this latest piece of sci-fi-must-have-geek-chicery brought to you by the power of graphene.
Jyongsik Jang and colleagues at Seoul National University describe the process in the journal Chemical Communications.
First, using techniques developed by other researchers, the team made graphene oxide from commercially available flakes of graphite. From this they derived their graphene “ink”. (More details on this step over at PhysOrg.)
The PhysOrg article explains that printing with graphene ink isn’t quite as simple as printing with the finest recycled HP-substitute: a little low temperature plasma work has to be done to prepare the surface. But once that is done making the graphene electrodes is a matter of printing on both sides of the treated Poly vinylidene fluoride (PVDF) and dunking the output in a hydrazine and ammonia solution for 3 minutes.
Sadly, this is primary research, so we can’t expect to see such things in the shops for a while. But for once, the hurdle is not one of basic science. The kit works, the manufacturing is relatively simple, and not crushingly expensive.
However, the sound quality isn’t quite there yet. The researchers say they are still working on the bass tones.
In the meantime, the researchers will have to be content with the knowledge that they have earned high praise from their peers. Jinyue Jiang, a post doc at the University of Nebraska, told the RSC: "The beauty of this technique lies in its potential for large scale production and its ability to control the location of graphene - [depositing] graphene thin films on various substrates."