Piezoelectric Energy Harvesting in the Real Environment with Multiple Excitations

Description

Energy harvesting is a promising renewable and long-lifespan power solution alternative to batteries for wireless devices. It has attracted much attention along with the booming of wearable devices and sensor networks. However, most existing harvesters cannot meet the power requirements from potential applications, owing to their low power-generation capability and poor environmental adaptability with narrow operational bandwidth. More seriously, most previous research is conducted in ideal laboratory environments with a single form of regular excitation, e.g., translational harmonic vibration. In contrast, the excitation sources in the real environment such as rolling tires and body motions are deformable and irregular. Usually combinations of various forms of excitations such as periodic vibrations, abrupt strong shocks and deformation exist simultaneously in the excitation bases, of which harsh environment can cause serious damage and performance deterioration. We believe it is very important to develop harvesters with the capability of working efficiently not only under one type of regular excitation, but also under the realistic multiple irregular excitations. This project is therefore aimed at exploring new methods for achieving high power-output and broad bandwidth for energy harvesting in environments where deformation, periodic vibration and shocks coexist. Based on our extensive research, we herein propose to develop a versatile vibration-impact-strain hybrid energy harvesting solution. Different from the existing research, both moderate periodic vibrations and strong abrupt acceleration changes will be captured via the unique compressive mode, force amplification mechanisms and the impact energy harvesting method to improve power output. Furthermore, highly-reliable multilayer piezoelectric composites will be developed to effectively harness strain energy associated with deformable excitation bases. To extend the operational bandwidth, geometric nonlinearity and magnetic nonlinearity will be introduced to energy harvesters and their interaction will be fully analyzed. Comprehensive theoretical analysis and systematic experiments will be performed to gain in-depth understanding of the effects of different parameters and nonlinear characteristics under different excitations, which provides guidelines for improving energy harvesting performances. For demonstration, we will at the end develop a self-powered tire condition monitoring system using the proposed harvesters and test it in running vehicles. To our best knowledge, this is the first research that combines kinetic and strain energy harvesting methods working with complex excitations. The new methods and knowledge generated from this project will greatly advance the research field of energy harvesting, nonlinear vibration and wireless sensors, which with no doubt will further promote the development of self-powered wireless devices significantly.