Multi‐Strategy Synergy Towards a High‐Performance Piezo‐Triboelectric Nanogenerator for Low‐Frequency Vibration Energy Harvesting

ABSTRACT To simultaneously address the low energy harvesting efficiency caused by the narrow operating frequency bandwidth of harvesters and the impedance mismatch among heterogeneous energy harvesting units, a compact piezo–triboelectric nanogenerator with dual stoppers is designed to harvest low‐frequency vibration energy. Secondly, an electromechanical coupling model of the hybrid harvester is established, and the parameters, such as the stopper stiffness and impact distance, are analyzed and optimized to broaden the operating frequency bandwidth of the piezo–triboelectric nanogenerator. Next, an experimental platform is established for validation, and the results indicate that the discrepancy between the simulated and measured natural frequencies is only 0.4 Hz for a cantilever beam with a thickness of 0.4 mm, thereby verifying the accuracy of the proposed model. Finally, an impedance matching method based on charge pumping is proposed to integrate the hybrid harvester units. Experimental results show that the output power of the integrated hybrid harvester increases by 239%, thereby achieving impedance matching among heterogeneous energy harvesting units and reducing energy losses caused by impedance mismatch.