Peter Burke and Chris Rutherglen at the University of California have unveiled a radio made of carbon nanotubes. It's a "detector" only a few atoms across, smaller than a human hair, nearly 1000 times smaller than any preceeding technology. This is the most important and complex part of a radio and it's only a few atoms in diameter. Obviously this lacks a speaker and an amplifer, but it can receive radio waves and convert them into sound.
Much like Shannon's limit (discussed Friday) Every transistor has a maximum speed at which it can function. For silicon, this should be approximately 100 GHz. But current circuits typically operate at less than5 GHz. The speed differnece is only limited by our ability to exploit it. The theoretical maximum speed limit for nanotube transistors should be in the terahertz range. I.E. more than 1,000x faster than silicon.
It was only in 2004 that Burke unveiled transistors made from single-walled carbon nanotubes. Those were aimed at the cell phone market being able to operate into the microwave range. It seemed like a hot item and Burke received a grant from the National Academies Keck Futures Initiative for $75,000 in 2005. So why the hell is he messing around with archaic technology like a radio?