摘要
论文提出了一种基于碰撞升频机制的微型压电能量采集系统,由一对共振频率不同的悬臂梁平行叠放组成.在外界低频振动激励下,底部低频S形金属曲梁产生共振,在运动过程中碰撞顶部高频微型压电直梁,从而将低频环境振动转换为高频压电梁的振动,解决了压电直梁的固有频率与外界激励频率不匹配问题.论文建立了压电悬臂梁受迫振动、压电悬臂梁与金属悬臂梁碰撞耦合振动的动力学模型,讨论了压电悬臂梁的电压输出特性.通过实验测试了压电能量收集系统和单个压电悬臂梁的开路电压并计算了输出功率,结果表明当振动加速度为1.0g时,升频式压电能量采集系统在25 Hz的激振下输出功率达到8.6μW,高于单个压电悬臂梁的最大输出功率.
This paper proposes an MEMS piezoelectric energy harvesting system(PEHS)working with the impact-based frequency up-conversion mechanism.By using this mechanism,the problem that the natural frequency of the piezoelectric cantilever does not match the external excitation frequency is solved.The PEHS mainly consists of a low-frequency stainless-steel cantilever with the resonant frequency of 25 Hz and a high-frequency piezoelectric cantilever with the resonant frequency of 935 Hz.These two cantilevers are placed in parallel.The conversion of low-frequency environmental vibration to high-frequency piezoelectric beam vibration is realized through the collision between the bottom stainless-steel cantilever and the top piezoelectric cantilever.During one collision cycle,the bottom stainless-steel cantilever is firstly triggered to resonate under the external low-frequency vibration excitation,then the stainless-steel cantilever collides with the top piezoelectric cantilever,and they move upwards together.The models of an energy harvesting system in which a low-frequency driving cantilever impacts a high-frequency generating cantilever are established and discussed.The output performances of the single piezoelectric cantilever at different accelerations and the output performances of the PEHS under different initial distances are tested.The experimental results demonstrate that under the external vibration of 935 Hz,the maximum output voltage of the single piezoelectric cantilever is 74 mV,and the maximum output power is calculated to be 0.11μW at 1.0g acceleration.While the maximum open-circuit output voltage of the PEHS can be 1220 mV at a relatively low excitation frequency of 25 Hz,the operating bandwidth of the PEHS is widened to 4.7 Hz and the maximum output power is calculated to be 8.6μW at an acceleration of 1.0g.It indicates that the impact-based frequency up-conversion mechanism can effectively reduce the operating frequency,widen the operating bandwidth and improve the vibration energy harvesting capability of the PVEH under low-frequency and low-acceleration vibration environment.
作者
黄曼娟
侯诚
李云飞
刘会聪
陈涛
杨湛
王凤霞
孙立宁
Manjuan Huang;Cheng Hou;Yunfei Li;Huicong Liu;Tao Chen;Zhan Yang;Fengxia Wang;Lining Sun(School of Mechanical and Electric Engineering,Soochow University,Suzhou,215123;Jiangsu Provincial Key Laboratory of Advanced Robotics,Suzhou,215123)
出处
《固体力学学报》
CAS
CSCD
北大核心
2019年第5期478-487,共10页
Chinese Journal of Solid Mechanics
基金
国家自然科学基金项目（51875377）
国家重大科研仪器研制项目（41527901）资助
关键词
MEMS
压电
振动能量采集器
碰撞升频机制
非线性
MEMS
piezoelectric
vibration energy harvester
impact-based frequency up-conversion mechanism
nonlinearity
