Nanotechnology made a significant advance in December 2010 as scientists contsructed the world’s first nanoradio receiver using graphene, the film-like carbon compound which made headlines earlier this year when its discoverers were awarded the Nobel prize.
According to the arXiv blog on Technologynews.com on December 22nd, 2010. A team of researchers at Columbia University in New York, working under Yuehang Xu, created a kind of trampoline structure using a graphene sheet stretched between two electrodes. A third electrode was placed underneath the sheet, which was then subjected to a small amount of DC current and a radio frequency voltage. The researchers found that this nano-scale device resonates at frequencies which can be easily detected by measuring the capacitance between the graphene sheet, and the electrode below that sheet.
Graphene, a molecule thick carbon compound originally formed by lifting layers from a lead pencil with Scotch tape in a Manchester University laboratory, is a super-light material with amazing properties of strength and flexibility, and the fact that it is so much less massive than, for example, silicon (from which scientists have tried to construct similar nano-scale devices in the past), means that it can detect much higher frequency radio waves, potentially moving up into the GHz range (currently Xu and the team can pick up a radio signal at 33.27 MHz), which could mean the technology could have serious applications for mobile phone manufacturers.
Graphene has been the magic ingredient in these nanoradio receivers. Previous attempts to build nano devices to receive and transmit radio signals have been thwarted by what is known as parasitic capacitance between the nano scale components, drowning out the very signals in which the scientists have been interested.
As always, although the effect has been demonstrated in lab conditions, it will be a while before you can pick up consumer devices which use graphene nanoradio receivers. For a start, graphene does not lend itself easily to mass production yet – as a molecule thick carbon sheet, producing the stuff is a fiddly procedure and Yuehang Xu’s team reportedly used tweezers and more adhesive tape to produce their stock. The nanoreceiver also needs to be massively cooled before it will work, as things stand. As much of the current research into graphene concerns methods of producing the material in greater bulk, it is to be hoped that these considerations will not be a serious barrier.
With this development in nanotechnology, graphene has begun to show some serious applications to back up the excitement generated by its discovery.
