Scientists from the Georgia Institute of Technology recently reported the development of what they say is the world's "first self-powered nano-device that can transmit data wirelessly over long distances." The tiny device is able to operate battery-free, using a piezoelectric nanogenerator to create electricity from naturally-occurring mechanical vibrations.
The five-layered, one square-centimeter nanogenerator was made from a flexible polymer substrate, with zinc-oxide (ZnO) nanowire textured films attached to that polymer's top and bottom surfaces, and electrodes on the outside surfaces of the nanowire films.
When mechanically strained by vibrations, it produces an output voltage of 10 volts, and an output current of over 0.6 microamps. Energy is stored in the nanodevice's built-in capacitor, and is used to power electronics including an infrared photon-detecting sensor, and a radio transmitter that uses technology similar to that found in Bluetooth headsets.
In tests, it was reportedly able to transmit wireless signals that could be detected by an ordinary radio, at distances of over 30 feet (9 meters). While only three straining cycles of the nanogenerator were required in order to generate enough power to transmit the radio signal, 1,000 cycles were necessary to power the sensor, and then transmit a signal once it was triggered. In a high-stress environment, however, the cycles could add up pretty quickly.
"This study proves the feasibility of using ZnO nanowire NGs [nanogenerators] for building self-powered systems with capability of long distance data transmission, clearly proving its potential application in wireless biosensing, environmental infrastructure monitoring, sensor networks, personal electronics, and even national security," the Georgia Tech team concluded in a paper on the nanodevice, which was recently published in the journal Nano Letters.
The research project was led by Professor Zhong Lin Wang.