螺旋形压电悬臂梁多方向振动能量采集器设计及性能分析OA北大核心CSTPCD

To adapt to multi-directional excitation input from vibration environment,a multi-directional vibration energy harvester is pro-posed based on spiral piezoelectric cantilever beams.The harvester is a bidirectional coupling vibration energy harvester composed of four-spiral piezoelectric beams,which are made by pasting polyvinylidene fluoride(PVDF)on a red copper basal layer.The vibration characteristics and energy harvesting performance of the single-and four-spiral piezoelectric beam structures are analyzed with the finite element simulation and experiments.The effects of shape parameters and lumped mass of the spiral structure on its natural frequency and load resistance on its output power are studied.Moreover,the open-circuit output voltage and power under different loads are ex-plored.The results show that the radius,radial pitch,weight and thickness have great effects on the natural frequency of the single-spiral piezoelectric beam.By adding 5 g and 10 g lumped masses,the first natural frequency changes from 29 Hz to 22 Hz and 18 Hz respec-tively compared with that of the non-lumped mass.The best external resistance,the peak voltage and the power are 1×107 Ω,12 V and 7 μW,respectively.For the multi-directional vibration energy harvester having four-spiral piezoelectric beams,the results show that the output voltage is up to 17 V when the amplitude of the exciter is 5 m/s2,which has a good multi-directional energy harvesting perform-ance from low-frequency vibration.