John Titus at ECN has recently published an article titled “Energy Harvesting Suits Remote Low Power Devices“, which includes updates on energy harvesting technology from multiple companies including CYMBET, Humdinger, Microstrain, Mide, and Powercast.
Grabbing “free” energy involves more engineering than buying an off-the-shelf transducer. Contrary to what you might think, the awareness of “green power” didn’t spawn the drive to harvest energy. Low-power electronic fabrication technologies did the trick. They cut the power needs of small monitoring devices to the point where energy harvesting has started to make engineering and economic sense.