A Four-in-One Compact Design of Monostable Quasi-Static-Toggling Mechanical Energy Harvester

Quasi-static-toggling (QST) mechanical energy harvester (MEH) can slowly accumulate a certain amount of mechanical potential energy. After the triggering position, it releases and converts the stored energy into useful electricity in an instant. It was designed into microgenerators for powering some ultra-low-powered Internet of Things (IoT) devices. This article introduces a 4-in-1 QST-MEH design. It uses a compact and deformable iron cantilevered beam to inclusively embody four key elements, i.e., an iron core, an energy-buffering spring, a rebounding spring, and a mechanical lever, which form a monostable QST electromagnetic generator. Compared with the existing designs, the proposed design reduces the component number to the most extreme. It largely helps reduce manufacturing and assembly procedures toward low-cost implementation and reliable operation. Experimental result shows that about 0.25 mJ of energy can be harvested from each round of press-release action with the experimental prototype. Such an amount of energy is sufficient to power an iBeacon bluetooth low-energy transmitter for motion-powered IoT applications.