A bioinspired structure modification of piezoelectric wind energy harvester based on the prototype of leaf veins

This paper describes a novel leaf-like piezoelectric wind energy harvester based on the venation growth algorithm, which are derived from the prototype of dicotyledonous plant leaves that have the netted distributions of veins. Some triangle polyvinylidene fluoride (PVDF) leaves are designed and fabricated to be the energy harvesting element that is driven by the vortex induced vibration in the wind flow behind a bluff body. Wind tunnel experiments were carried out to investigate and compare the performances of energy harvesting capacity of different elements. Experimental results show that the output powers of the veined structures are 4-6 times higher than that of the structure without veins. The largest root mean square of open circuit output voltage reaches 1.094 V under the wind velocity of 11 m/s for the 110 μm thickness PVDF leaf with veins. The dynamic analysis indicates that the veins can greatly influence the mechanical coupling properties between the harvesters and the wind flow although the system has not reached a typical state of instability. It is confirmed that the presence of veins has an important effect on the efficiency of the energy harvesting system.