A team of engineers from Columbia University has created a nano-mechanical system with the ability to create FM radio signals. In other words, they've built what is effectively the world’s smallest FM radio transmitter.

Using graphene (a single atomic layer of carbon recognized for its strength and superior electrical properties), the team led by Professor James Hone and Professor Kenneth Shepard created a nano-mechanical version of an electrical component known as a Voltage Controlled Oscillator (VCO).

“This device is by far the smallest system that can create FM signals,” says Professor Hone.

As VCOs have the ability to generate frequency-modulated (FM) signals, Hone and his team used graphene to create a nano-sized version with a frequency of 100 megahertz, which is within the FM radio band (87.7 to 108MHz).

To demonstrate the device, the team modulated low-frequency musical signals from the graphene before retrieving them using a regular FM radio receiver.

The development is seen as a step towards decreasing the size of radio signal devices, which have proved more difficult to miniaturize than electrical circuits, hindering the development of the consumer devices that utilize both.

“These ‘off-chip’ components take up a lot of space and electrical power,” says Hone. “In addition, most of these components cannot be easily tuned in frequency, requiring multiple copies to cover the range of frequencies used for wireless communication.”

Hone notes that there there is a long way to go before the technology can be applied to commercial products.

“It is an important first step in advancing wireless signal processing and designing ultrathin, efficient cell phones,” he says. “ Our devices are much smaller than any other sources of radio signals, and can be put on the same chip that is used for data processing.”

The study is published in Nature Nanotechnology.