Investigations On Nonlinear Energy Harvesters In Complex Vibration Environments For Robust Direct Current Power Delivery

With an explosion of the internet of things, energy harvesting provides an environmentally friendly solution to replace consumable batteries in powering wireless sensors. The goal of the research is to bridge a fundamental disconnection in the state-of-the-art understanding of dynamic, multiphysics interplay in vibration energy harvesting systems. In this spirit, vibration energy harvesting systems that integrate structural and electrical nonlinearities are examined to create knowledge on intricate dynamics when subjected to complex vibration environments. The revealed principles may build foundations for techniques to capitalize on synergistic dynamic responses and deliver sustainable robust DC power. In the dissertation, theoretical frameworks that synthesize the mechanical and electrical nonlinearities have been established to examine the intricate dynamics of the integrated nonlinear energy harvesting system. The proposed analytical formulations have been validated by experiments and present particular efficacy to probe the nonlinear dynamics and regulated electrical power, which may help guide the design and deployment of nonlinear energy harvesting systems under complex vibration environments. Moreover, the principles of impedance have been employed to scrutinize the energy transfer in the complex and nonlinear multiphysics network to shed light on strategies for maximizing the energy conversion efficiency of the integrated nonlinear energy harvesting system. The uncovered dynamical characteristics and optimal strategies facilitate insights on the suitable integration of sub-systems and assist in the development and deployment of high-efficiency and sustainable energy harvesting systems. The new knowledge on the system-level harvester implementation may also guide the advancements of other fields, where wireless sensor networks are possibly deployed, such as medical implantation, civil infrastructure health monitoring, and wildlife tracking.