悬臂梁压电式能量收集器频带扩展研究

Research on Frequency Band Extension of Cantilever Beam Piezoelectric Energy Harvester

为了扩宽悬臂梁压电式能量收集器的工作频带,提出了一种新型的电学连接方案。通过将悬臂梁表面电极分为两个对称区域,实现扭转模态下正负电荷的有效收集。对悬臂梁的结构尺寸进行优化,使弯曲模态接近扭转模态的谐振频率,以扩宽压电式能量收集器频带。根据Erturk的分布参数机电模型,研究了两种模态下的输出电压与固有频率。研究结构表明,当悬臂梁长宽比在3.25~3.35范围内,1阶扭转模态频率接近2阶弯曲模态频率,实现了能量收集器的频带扩宽。该工作对悬臂梁压电式能量收集器的研究和应用具有一定的借鉴意义。

In order to widen the working frequency band of the piezoelectric energy harvester based on cantilever beam, a novel electrical connection scheme was proposed. By dividing the surface electrode of the cantilever beam into the symmetrical regions, the positive and negative charge under the torsional mode could be effectively collected. Then the structural size of the cantilever beam was optimized to make the resonant frequency of the bending mode and torsional mode close, so as to achieve the purpose of widening the frequency band of the piezoelectric energy harvester. Finally, according to Erturk’s distributed parameter electromechanical model, the output voltage and the natural frequency of two modes were studied. It was found that when the length-to-width ratio of the cantilever beam was within the range of 3.25 to 3.35, the first-order frequency of the torsional mode was close to that of the second-order bending mode, which realized the frequency band extension of the energy harvester. This work had certain reference significance for the research and application of the piezoelectric energy harvester based on cantilever beam.