How easy can it be to make a radio? Well how about in four steps:
- Place two electrodes and stretch a sheet of graphene between them to form a trampoline.
- Get a third electrode and place it under the trampoline and supply a DC current to it.
- Add radio frequency voltage and you are done.
Impressed? I bet you are and this exactly what a Columbia University student named Yuehang Xu did in New York with his friends.
This is a significant achievement because physicists were finding a way for some years now to use nono-electro-mechanical resonators to generate radio signals. The nano-electro-mechanical devices were a victim of parasitic capacitance but Xu says that their graphene based device is immune from this. They proved this by creating a device that caught radio signals at 33.27MHz- believe it!
The device can be improved and can perform better as graphene sheets are, unlike their silicon based friends, smaller about two orders of magnitude. This property will enable them to catch higher frequencies. Xu and company even say that their device can measure signals in the GHz range. If it turns out like this then a lot mobile manufacturers will be chasing Xu and his friends.
There are a few problems though which have to be addressed. The major issue is that how to make grphene trampoline. The experiment was performed with the help of tweezers but it is not a suitable method for mass production. If this device has to be used in the consumer devices then its operating temperature, which is currently at 77K, will have to be boosted. However, these are not the sort of problems that cannot be sorted out.
Physicists were certain about the amazing properties of graphene and had predicted its importance in microelectronics decades ago. What is amazing is that we are witnessing it quite quickly. After all that noble prize was worth it.