Design of Tree-Like Tri-Fork Piezoelectric Vibration Energy Harvester and Its Validation Experiments
In harvesting wideband and weak vibration energy in practical environments,classical piezoe-lectric energy harvesters often can't give a high electric output.To overcome this limitation,we intro-duce a novel design of tree-like tri-fork vibration energy harvester with piezoelectric patches bonded to the clamped end.Under base excitations,the harvester is expected to be able to produce large ampli-tudes and electric outputs.Firstly,the mathematical model is established,and corresponding simula-tions are conducted.Then,the prototype was fabricated and validation experiments are carried out.The experimental results prove that under wideband stochastic excitations,the harvester can oscillate with a large amplitude and produce large output.Based on the results,we upgrade the structure by adding a mass on the tip of middle beam,the inertial force produced by the tip mass under excitation can drive the tri-fork beam to generate large vibration and output.Corresponding experiments were carried out to ver-ify the improved structure.The results show that with the change in structure,the electric output increa-ses dramatically for the same excitation intensity.For the stochastic excitation of PSD=0.045 g2/Hz,across a piezoelectric patch featuring the size of 20 mm×10 mm×2 mm,the structure with the middle tip mass can produce an output of RMS power of 61.72 μW,about 2.32 times that without the tip mass.
wideband excitationenergy harvestingtri-fork beampiezoelectric materialoutput power
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维普
