Washington, Nov 1 : Scientists at the University of California have devised the smallest radio ever, which is 100 billion times smaller than the first commercial radio.

The radio is a single carbon nanotube, one ten-thousandth the diameter of a human hair, and requires only a battery and earphones to start functioning.

The scientists successfully received their first FM broadcast last year - Derek & The Dominos' "Layla" and the Beach Boys' "Good Vibrations" transmitted from across the room.

Alex Zettl, UC Berkeley professor of physics and the team leader, said the nanoradio is currently configured just as a receiver, but it could also work as a transmitter. It could be used in any number of applications - from cell phones to microscopic devices that sense the environment and relay information via radio signals.

“The nanotube radio may lead to radical new applications, such as radio-controlled devices small enough to exist in a human's bloodstream,” the authors wrote in a paper published online today by the journal Nano Letters.

Authors of the nanoradio paper are Zettl, graduate student Kenneth Jensen, and their colleagues in UC Berkeley's Center of Integrated Nanomechanical Systems (COINS) and in the Materials Sciences Division at Lawrence Berkeley National Laboratory (LBNL).

In this radio, a single carbon nanotube works as an all-in-one antenna, tuner, amplifier and demodulator for both AM and FM. In comparison, a standard radio has separate components for these functions.

What makes the nanoradio a true nanoelectromechanical device is the fact that it detects radio signals in a radically new way-- it vibrates thousands to millions of times per second in tune with the radio wave.

While large objects, like a stiff wire or a wooden ruler pinned at one end, vibrate at low frequencies - between tens and hundreds of times per second- the tiny nanotubes vibrate at high frequencies ranging from kilohertz (thousands of times per second) to hundreds of megaHertz (100 million times per second).

The field-emission and vibration together also demodulate the signal.

"I hate to sound like I'm selling a Ginsu knife - But wait, there's more! It also slices and dices! - but this one nanotube does everything; it performs all radio functions simultaneously and extremely efficiently," Zettl said. "It's ridiculously simple - that's the beauty of it." (ANI)