Boffins claim that they have created a self-powered nano-device that can transmit data wirelessly over long distances. According to ACS's journal, Nano Letters, they say it proves it is possible to make tiny gear  that operates independently without batteries on energy collected from the environment.

Zhong Lin Wang  wrote that that advances in electronics have opened the door to developing tiny devices that operate battery-free on minute amounts of electricity that can be harvested from the pulse of a blood vessel or a person walking. It should be possible to drive the devices by taking energy from sources in the environment such as gentle airflow, vibration, sonic wave, solar, chemical, and/or thermal energy.

Each nano device is made up of a nanogenerator that produces electricity from mechanical vibration or triggering, a capacitor to store the energy, and electronics that include a sensor and a radio transmitter. Their device transmitted wireless signals that could be detected by an ordinary commercial radio.