This carbon nanotube, imaged by a transmission electron microscope, can act as a radio.
Building a Nano Radio
A radio receiver made from a carbon nanotube could be used to wirelessly transmit data from ultrasmall sensors
Source: “Nanotube Radio”
Alex Zettl et al.
Nano Letters 7: 3508-3511
Results: Researchers at Lawrence Berkeley National Laboratory in California have modified a carbon nanotube so that it performs the functions of a radio, even tuning in the entire FM radio band.
Why it matters: Radios are used in everything from cell phones to nodes in sensor networks, and like other electronics, they are shrinking in size. A nanoscale radio could someday find its way into portable electronics such as cell phones. The researchers also suspect that with its small size, the radio could be inserted into a biological cell to transmit information collected by tiny sensors that detect molecular processes.
Methods: The researchers grew the carbon nanotube on a tungsten surface that acts as a negative electrode; a positive copper electrode is separated from the nanotube by a vacuum gap. A voltage applied to the electrodes causes a current to flow through the nanotube, turning the radio on. Changing the voltage also changes the vibrational rate of the nanotube, tuning it to a different frequency.
Next steps: The researchers are looking to integrate the radio into biological systems.