Structure optimization and performance of piezoelectric energy harvester for improving road power generation effect

This paper presents a cantilever piezoelectric energy harvester with excellent electrical output and mechanical characteristics for roads, which solves the problems of low electrical output level and low matching with road traffic of cantilever piezoelectric energy harvesters at present. Based on the finite element model, the structural characteristics of the energy harvester under different constraint forms are analyzed. The energy harvester structure is optimized according to the electrical output and stress distribution characteristics, and the size with high electrical output and good stress distribution is clarified. Finally, the good electrical effect of the proposed energy harvester structure and size is determined. The results indicate that the rigidly constrained energy harvester has higher potential and stress of the piezoelectric layer than the cantilever constrained, but the charge cancellation at both ends of the piezoelectric layer is obvious. Then the fixed end position and the displacement application position are considered to alleviate this phenomenon, and the former has obvious benefits in improving the electrical output effect and reducing the stress value. From the perspective of mechanics and electricity, the output voltage and output power of the energy harvester under the optimal size up to 24 V and 4.381 mW respectively, which are higher than other cantilever energy harvesters. The optimized energy harvester improves its electrical effect and mechanical characteristics under actual road traffic conditions, which lays a foundation for the cantilever piezoelectric energy harvester to collect road vibration energy.