Researchers made an accidental discovery that has revolutionize tracking devices – Think, Cheap, Powerful radio pulse emitters, that need no battery. The research were working on something unrelated to this, when they detected a powerful radio pulse coming from a bag of junk circuit boards and components, every time the bag was moved.
The source of the signal was tracked down, and the researchers worked on it, to develop – Agitate – a small device with two metal plates, that is no bigger than a coin. One plate is made of metal and the other a material that stores charge. When either one of the plates is moved, even a tiny amount, the mechanical energy of the movement is transformed into electrical energy that is released as a short radio pulse. The signal is very brief, only a second or two, but it is more powerful than the signal from a cell phone. The pulse is very precise and can be tracked to the device’s location.