High performance hybrid omnidirectional wind energy harvester based on flutter for wireless sensing and hydrogen production applications

Wind energy harvesters (WEHs) based on wind–induced vibration (WIV) attract increasing attention as the power sources of wireless sensor nodes. The wind direction in natural environments usually changes over time, therefore, it is of significance to develop omnidirectional wind energy harvesters (OWEHs). This paper presents a triboelectric–electromagnetic–piezoelectric hybrid OWEH based on flutter. The secondary collision is introduced into the harvester to improve the electricity produced through triboelectric effect. The efficient electromagnetic electromechanical conversion is realized using planar coils and two magnets with the same magnetic poles facing each other. Experiments are conducted to optimize the prototype and evaluate its performance. The optimized prototype has a wide wind speed range of 3.6–20 m/s and a wind direction range of 0°-360° in the specified plane. The maximum total average output power at 20 m/s is 6.84 mW, respectively. A wireless sensor node power by the prototype measures and sends out the humidity and temperature with a time interval of 2.02–2.43 seconds at 5.3 m/s. A water electrolysis hydrogen production system powered by the prototype produces about 33.8 μL hydrogen per minute at 20 m/s. The high output power, wide speed range, and wide wind direction range of the proposed harvester greatly expand the application scenarios of WIV WEHs.