A MULTI-DIRECTIONAL LOW-FREQUENCY ELECTROMAGNETIC ENERGY HARVESTER

Low-frequency multi-directional vibrations pose one of the main challenges for energy harvesting to provide sustainable power for electronic devices in real applications. This work presents an energy harvester design that can covert low-frequency multi-directional vibrations to rotational motions and generate electricity for consumer electronic devices. With the implementation of a spring supported rotational electromagnetic transducer, the device can adapt to vibrations in any direction and achieve an average power of 1.14 mW when excited at 2.4 Hz and 0.2 g. A power management circuit is designed to regulate the output to an appropriate voltage and successfully provide the power for continuous operation of low-power electronics. For wireless sensors that demand high start-up power consumption, further improvement in power management is required to ensure the cold start of the device after enough energy is harvested and stored by the developed harvester.