基于谐振器的多模态压电换能结构研究

A piezoelectric cantilever with an oscillator for multi-mode vibration energy harvesting

传统压电悬臂梁俘能器一般通过其基频与环境中某一激振频率的匹配来收集这个频率上的振动能,为俘获环境中多个激振频率上的能量,提出一种在压电悬臂梁上附加谐振器的多模态换能结构,由该结构组成的俘能器的前两阶共振频率可以被设计在给定的激振频率上,从而有效地收集分布在这两个频率上的能量。实验表明附加谐振器有效地提高了俘能效率,其中一阶模态的俘能效率相对附加等量质量块时提高了71%,二阶模态的俘能效率与原压电悬臂梁的一阶模态相当。

Piezoelectric cantilever, as a typical vibration-based energy harvester, usually works at its fundamental frequency which may match only one ambient exciting frequency. In order to harvest the power distributed in more exciting frequencies, this paper develops a multi-mode energy harvesting structure which involves a piezoelectric cantilever with an oscillator. By tuning the first two resonant frequencies of the proposed structure to match the corresponding exciting frequencies, the ener- gy stored in these frequencies can be efficiently harvested. Experimental results show that the energy harvesting efficiency of the oscillator-attached structure increases by 71~ compared to that of the mass-attached structure with the same weight at the first vibration mode. In addition, at the second vibration mode the energy harvesting efficiency is equivalent to that of the simple piezoelectric cantilever at its first vibration mode.