It is difficult to efficiently harvest the energy of weak and broadband vibrations existing in the environment. In this study, a piezoelectric vibration energy harvester incorporating a lever structure and bi-stability is proposed. Under base excitation, the lever can amplify the displacement and make the piezoelectric beam execute a bi-stable snap-through motion easily, thereby producing large electric outputs. The electromechanical equations are derived, and corresponding simulations are carried out. The analyses on potential energy indicate that the harvester can be symmetrically and asymmetrically bi-stable under gravity. Then the harvester’s prototype is fabricated and the validation experiments are carried out. The frequency-sweeping experiment shows that the harvester owns a wide frequency band. The experiment for random excitation proves that the harvester could execute bi-stable vibration and produce relatively high output under broadband and weak excitations. For a random excitation with a power spectral density (PSD) of 0.035 g/Hz, the harvester can generate an output power with a root mean square (RMS) of 29.41 μW.

中文翻译：

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通过杠杆式机构提高弱激励振动能量收集的性能


很难有效地收集环境中存在的微弱和宽带振动的能量。在这项研究中，提出了一种结合杠杆结构和双稳定性的压电振动能量收集器。在基极激励下，杠杆可以放大位移，使压电梁轻松地执行双稳态突跳运动，从而产生较大的电输出。推导了机电方程，并进行了相应的仿真。势能分析表明，收割机在重力作用下可以实现对称和非对称双稳态。然后制作了收割机样机并进行了验证实验。扫频实验表明该采集器具有较宽的工作频段。随机激励实验证明，该采集器可以在宽带弱激励下执行双稳态振动并产生较高的输出。对于功率谱密度 (PSD) 为 0.035 g/Hz 的随机激励，采集器可产生均方根 (RMS) 为 29.41 μW 的输出功率。