Wireless devices depend on batteries—at least for now. Soon, they will be able to draw power from their own kinetic energy. Perpetuum Ltd. and Innos have teamed up to develop a siliconembedded self-powered wireless device that feeds off of the vibrations in the environment to produce usable energy.
Smaller than a matchbox, Perpetuum's electromecanical system comprises an arrangement of magnets on a vibrating beam. These magnets move past a coil, generating up to 4 mW. That's enough juice to power a sensor, microprocessor, and radio link. Perpettuum and Innos then developed a silicon microelectromechanical-system (MEMS) microgenerator that's 5 by 5 by 1.5 mm.
The Perpetuum Silicon MEMS Microgenerator can produce a few hundred microwatts under suitable conditions. It can drive sensors, small microprocessors, and RF transmitters for a completely self-powered system. "Imagine a heart pacemaker that uses the patient's own body energy to power it, eliminating the need for a battery and the associated operations to replace them," says Andrew Monk, CEO of Innos.
According to Perpetuum CEO Roy Freeland, the next crucial step is to considerably reduce the device's size and cost by embedding it in silicon. The companies predict a host of self-powered monitoring applications after that's achieved.
Such systems could watch machinery like motors, turbines, pumps, and gearboxes. They also could power and deliver signals from sensor systems to test rotating parts, wheels, rotors, shafts, and propellers. Systems could be permanently embedded in inaccessible structures like bridges and roads. And, they could be integrated into vehicle, container, and asset tracking.