Wind energy harvesting using piezoelectric macro fiber composites based on flutter mode

Abstract

Mechanical energy such as the wind flow widely exists in nature as renewable and sustainable energy source. It could be converted into electrical energy throughout piezoelectricity which has capability for converting mechanical energy into electrical energy. In this paper, an innovation piezoelectric energy harvesting (PEH) system is proposed by using the piezoelectric macro fiber composites (MFC) based on flutter mode. It is demonstrated that this PEH-MFC system exhibits the excellent characteristic of flexibility on large deformation and reliability in energy harvesters and effectively captures power from wind energy. The PEH-MFC system is composed of a soft substrate linked with a polymer triangular leaf by a copper hinge. The active MFC is attached at the bottom of the soft substrate as the core component of system. A series of experiments on energy harvesting systems for various substrate materials and various types of MFC are performed in wind tunnel. The flutter mode is obtained under the critical flutter wind speed in order to acquire the excellent behavior of extracting power through this innovation PEH-MFC system. The experimental results show that the thickness and stiffness of PEH substrate have significant effects on the performance of energy harvesting. The maximum peak-to-peak open circuit voltage of 82 V is obtained using the MFC-2807 with Al substrate at the wind speed of 7.5 m/s. The resulting direct voltage and electric power are 25.8 V and 0.54 mW with a load resistance of 680 kΩ, respectively. It is concluded that the proposed energy harvesting system using MFC based on flutter mode can generate a power efficiency of 9.18 mW/cm3 which can meet the requirement of conventional MEMS.