الفهرس 
Background and MotivationOnly 14 pages are availabe for public view
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Abstract
Recently, with the urgent need for renewable and clean energy sources, emphasis has been placed on extracting and generating energy from the surrounding environment. Harvesting mechanical kinetic energy is an attractive field for easy access to energy from multiple sources, and transforming it from the mechanical domain to the electrical domain. Resonant systems introduced a viable solution in maximizing the output power when the ambient frequency is equal to the natural frequency of the device. However, a major drawback of these systems is their operation outside the resonance zone, which leads to a significant reduction in the output power.
This investigation discusses the design of an innovative autonomous mechanism for tuning the resonant frequency thereby generating larger amounts of energy. Unlike previous studies, which rely on tuning the resonant frequency by changing the stiffness of the system, the proposed concept is based on adjusting the system’s mass moment of inertia, hence changing the natural frequency by using a frequency tuning algorithm to maintain the system in a state of resonance. The proposed energy harvester employs electromagnetic induction to transform mechanical vibration into electric power.
The proposed design is analyzed using an approximate single degree of freedom model, and a continuous system to investigate the effect of different parameters of the tuning mechanism on eigen-frequency and also to determine the response of the system and the harvested power.
The tuning mechanism has been examined experimentally and validated by comparing its results with the analytical results. It is worth mentioning that this proposed design is suitable for low frequencies and this approach can be a viable step towards the production of autonomous energy harvesters.