A Clivia-like piezoelectric wind energy harvester using an overlapping multi-sheet structure

In this Letter, a Clivia-like piezoelectric wind energy harvester (CL-PWEH) using an overlapping multi-sheet structure is presented to enhance the robustness of wind-induced vibration energy harvesters at the unpredictable wind scenarios. The CL-PWEH was characterized by piezoelectric vibrators independent of the main vibration beam, Clivia-leaf-style vibrators, and rigid-flexible contact plucking. The feasibility of the proposed CL-PWEH was demonstrated through the theoretical analysis, fabrication, and wind speed responses experiments. The results showed that the length and thickness of flexible sheets had a strong influence on wind-induced vibration mode, output voltage, effective bandwidth, and cut-in wind speed. The output voltage was enhanced with the rising thickness ratio, and the bandwidth was decreased with the increase in the length ratio. In addition, the maximum output power of 5.82 mW was achieved for the CL-PWEH at α = 1.3, β = 4.5 at the optimum load resistance of 300 kΩ. Meanwhile, the application as a power supply illustrated that the CL-PWEH prototype could light up 200 blue LEDs in series.