MEMS低频压电振动能量采集器

设计了基于微机电系统（MEMS）的一阶、二阶传动低频压电振动能量采集器，通过压电效应将低频振动能量转化为电能来解决低频（小于200 Hz）振动环境中的能量采集问题。一阶传动能量采集器模型包括一阶传动梁及压电悬臂梁，二阶传动能量采集器模型包括一阶传动梁、二阶传动梁及压电悬臂梁。数学建模及有限元分析显示：采集器工作频率随一阶、二阶传动梁及压电悬臂梁材料的杨氏模量的减小均呈单调递减的趋势；传动梁的设计可有效降低采集器的高阶工作频率、拓宽工作带宽；而二阶传动梁可以在1g加速度条件下，获得10.98 Hz和44.52 Hz两个超低频率的电压峰值（分别为3.18 V/g和1.33 V/g），使系统工作频率降得更低，50 Hz以下的有效工作带宽更宽，更适合与低频振动环境匹配进行能量采集。

MEMS-based low-frequency piezoelectric vibration energy harvester

The first order and second order MEMS-based transmission low-frequency piezoelectric vibration energy harvesters are designed, which transform the vibration energy under a low-frequency environment (less than 200 Hz) into electricity through a piezoelectric effect to solve the problem of vibration energy harvesting. The first-order transmission energy harvester model includes a first-order transmission beam and a piezoelectric cantilever, the second-order transmission energy harvester model incorporates a first-order transmission beam, a second-order transmission beam and a piezoelectric cantilever. The results of mathematical modeling and finite element analysis indicate that the operating frequency of the energy harvester decrease monotonically with the decline of the Young modulus for the first and second order transmission beams and the piezoelectric cantilever; the design of transmission beam effectively reduces the high-order operating frequency of the harvester and broadens the operating bandwidth. As compared with the first-order transmission beam, the second-order transmission beam has acquired two voltage peaks (respectively 3.18 V/g and 1.33 V/g) at ultra-low frequencies (10.98 Hz and 44.52 Hz) with the acceleration of 1g, which further lowers the system operating frequency and widens the effective working bandwidth (less than 50 Hz). Obtained results show the harvesters are suitable for low-frequency vibration energy harvesting.