Duan Guan, Li Yingwei, Tan Chi
School of Chemistry and Civil Engineering, Shaoguan University, Shaoguan 512005, China.
School of Civil Engineering and State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China.
Micromachines (Basel). 2022 Jul 31;13(8):1227. doi: 10.3390/mi13081227.
A vibration piezoelectric energy harvester (PEH) is usually designed with a resonance frequency at the external excitation frequency for higher energy conversion efficiency. Here, we proposed a bridge-shaped PEH capable of tuning its resonance frequency by applying a direct current (DC) electric field on piezoelectric elements. A theoretical model of the relationship between the resonance frequency and DC electric field was first established. Then, a verification experiment was carried out and the results revealed that the resonance frequency of the PEH can be tuned by applying a DC electric field to it. In the absence of an axial preload, the resonance frequency of the PEH can be changed by about 18.7 Hz under the DC electric field range from -0.25 kV/mm to 0.25 kV/mm. With an axial preload of 5 N and 10 N, the resonance frequency bandwidth of the PEH can be tuned to about 13.4 Hz and 11.2 Hz, respectively. Further experimental results indicate that the output power and charging response of the PEH can also be significantly enhanced under a DC electric field when the excitation frequency deviates from the resonance frequency.
振动压电能量收集器（PEH）通常设计为在外部激励频率下具有共振频率，以实现更高的能量转换效率。在此，我们提出了一种桥形PEH，它能够通过在压电元件上施加直流（DC）电场来调节其共振频率。首先建立了共振频率与直流电场之间关系的理论模型。然后进行了验证实验，结果表明通过对PEH施加直流电场可以调节其共振频率。在没有轴向预载的情况下，在-0.25 kV/mm至0.25 kV/mm的直流电场范围内，PEH的共振频率可改变约18.7 Hz。在轴向预载为5 N和10 N时，PEH的共振频率带宽可分别调节至约13.4 Hz和11.2 Hz。进一步的实验结果表明，当激励频率偏离共振频率时，在直流电场下PEH的输出功率和充电响应也可显著增强。
