الفهرس 
Energy Harvesting System DesignOnly 14 pages are availabe for public view
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Abstract
At present, many wireless sensor nodes are used in many applications; in order to power these nodes in such applications, batteries with inherently limited life-times as well as chemical fuel sources may be considered; however, these solutions increase the size, complexity and cost of the devices substantially, since battery replacement is not an option for networks with thousands of physically embedded nodes.
The most feasible and most commonly observed sources of energy with MEMS mi-cro power generators include: vibration or mechanical movement, chemical com-bustion, chemical reactions, thermal gradient and solar power.
While many alternative methods of providing energy to wireless sensor nodes ex-ist, piezoelectric vibrational energy harvesters are generally considered the simplest approach while still allowing for potentially large power generation from the am-bient environment. This quality makes them ideal for truly remote applications, such as those in wireless sensor nodes or in Bio-MEMS.
In this thesis, a piezoelectric energy harvester is designed that harvests energy from mechanical vibrations. The designed harvester is modeled, simulated, and tested. The utilization of stretching strain as a main source for energy harvesting from a clamped-clamped beam structure is investigated. This structure exhibits nonlinear dynamics under certain conditions, which is modeled as a single degree of freedom (SDoF) electromechanical system.
The proposed model accuracy is then veri ed using nite element modeling (FEM), and experimental testing. The results of the model show a highly nonlinear system
with a ”Du ng” frequency response that can be used to design an ultra-wide bandwidth energy harvesting system suitable for practical applications.
A design of 9:9mm3 energy harvester is proposed using polyvinylidene uoride (PVDF) that can generate up to 4 W from vibrations of 0:5g at 70Hz. Moreover, a design of 53:5mm3 (29:7mm3 piezo. material + 23:8mm3 proof mass) energy harvester was tested using PVDF that can generate up to 15 W from vibrations of 0:5g at 128Hz and 2M load. The design can also generate up to 41 W from vibrations of 1g at 140Hz and 2M load.