According to the engineer Khalil Najafi, creator of the Parametric Frequency Increased Generators (PFGIs for its acronym in English), these convert into electrical energy the vibrations that are generated by the traffic of vehicles on a street, a bridge or a tunnel, and even by the movement of the muscles of people who walk, or who go up and down stairs.
Its generators have shown that they can produce up to 0.5 milliwatts from the vibration amplitudes found in the human body . This is enough power to run a wristwatch, which requires between one and ten microwatts, or a pacemaker, which requires between 10 and 50. One milliwatt is equivalent to 1,000 microwatts.
In the future, Najafi hopes to apply these batteries in wireless remote sensors , for example to detect small signs of corrosion in bridges and buildings, as well as in medical devices implanted by surgery, which are devices for a lifetime in which it is very expensive. replacement of depleted batteries ?.