To deal with the limited availability of long-lasting power sources for sensor nodes in industrial environments, a novel piezoelectric energy harvester with high efficiency and a wide working bandwidth was designed to harvest broadband and random vibrations from the ambient environment. The developed energy harvester adopts a doubly clamped piezoelectric beam with a peanut-shaped auxetic structure to improve the power output. It also incorporates a sliding proof mass for frequency self-tuning, enabling a wider working bandwidth. As the doubly clamped beam exhibits geometry nonlinearity under large vibration amplitudes, the power output of the energy harvester can be further enhanced in the frequency self-tuning process. Finite element simulations are conducted to evaluate the impact of the auxetic structure and the position of the proof mass on the performance of the energy harvester. Experiments are performed to examine the energy harvesting performance of the proposed energy harvester. Under an excitation acceleration of 0.3 g, the use of the sliding proof mass widens the working bandwidth of the auxetic energy harvester (AEH) by 9 Hz, with the maximum root mean square output power of AEH reaching 18.78 μW, which is much higher than that of the plain energy harvester (PEH) or the AEH with a fixed proof mass. The developed energy harvester can successfully power a wireless temperature and humidity sensor node based on the vibration produced by a centrifuge, which demonstrates the practical feasibility of the proposed energy harvester for industrial applications.

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具有频率自调节能力的拉胀压电能量收集器的数值和实验研究

为了解决工业环境中传感器节点持久电源可用性有限的问题，设计了一种具有高效率和宽工作带宽的新型压电能量收集器，用于从周围环境中收集宽带和随机振动。所开发的能量收集器采用具有花生形拉胀结构的双夹紧压电梁来提高功率输出。它还包含用于频率自调谐的滑动检测质量，从而实现更宽的工作带宽。由于双夹梁在大振动幅度下表现出几何非线性，因此能量收集器的功率输出可以在频率自调谐过程中进一步增强。进行有限元模拟来评估拉胀结构和检验质量的位置对能量采集器性能的影响。进行实验以检查所提出的能量收集器的能量收集性能。在0.3 g的激励加速度下，滑动检测质量的使用将拉胀能量采集器（AEH）的工作带宽拓宽了9 Hz，AEH的最大均方根输出功率达到18.78μW，远高于普通能量采集器 (PEH) 或具有固定检测质量的 AEH。所开发的能量收集器可以成功地根据离心机产生的振动为无线温度和湿度传感器节点供电，这证明了所提出的能量收集器在工业应用中的实际可行性。