A hybrid flapping-blade wind energy harvester based on vortex shedding effect

We proposed a hybrid piezoelectric and triboelectric-based wind energy harvester with high output performance. A square-shaped flapping blade and two spindle-shaped outer frames are specifically designed to enhance the vortex shedding effect. As wind flows across the device, both the piezoelectric and triboelectric parts produce power outputs at the same time. The cut-in wind speed of the device is as low as 4 m/s and the voltage outputs get improved with the increase in wind speed. As wind speed reaches 14 m/s, the open circuit peak voltage outputs of the piezoelectric, and the upper triboelectric parts are 19.8 and 17.4 V, respectively. The maximum power outputs of these two parts can be obtained as 112 and 76 μW at a wind speed of 10 m/s, with optimized load resistances of 0.6 and 0.9 MΩ, respectively.