Kablosuz sensör düğümleri için FR4 bazlı elektromanyetik enerji üreticileri

Wireless Sensor Nodes (WSN) are used for environment monitoring in many engineering applications. Powering these small sensors with battery is not reasonable due to regular replacement needs and the added size and mass of the batteries. Therefore, these sensors could be powered with environmental vibration sources via vibration-to-electrical energy harvesters.Electromagnetic (EM) energy harvesting (scavenging) seems to be one of the most promising ways to power wireless sensors in a wireless sensor network. In this thesis, FR4, the most commonly used printed circuit board (PCB) material, is utilized as a mechanical vibrating structure for EM energy harvesting to power body worn sensors and intelligent tire sensors. The fundamental property of such vibration sources are that even though the impact frequency is relatively low, the signal is nearly periodic, the impact duration is short, and the vibration signal is rich in harmonic content. FR4 can be a better material for such applications compared to Silicon MEMS devices due to lower stiffness and broadband response.In order to demonstrate FR4 performance and broadband response, moving magnet type EM generator designs are developed and investigated throughout this work. A magneto-electro-mechanical simulation model including the magnetic damping effects is developed and the results agree well with the experimental results. Human running acceleration at hip area that is obtained experimentally is simulated in order to demonstrate system performance, which results in a scavenged power of about 40 ?W with 15 m/s2 acceleration input. Mechanical stopper structures are built in the energy harvester design to limit the stress on suspension springs and to achieve efficient energy scavenging from nearly periodic and non-sinusoidal high-g excitations with rich harmonic content.For the intelligent tire applications, a compact FR4 scavenger designed that is able to withstand large shocks and vibrations due to non-linear mechanical shock stoppers built in the structure. Using our design, 0.4 mW power across a load resistance of 100W at off-resonance operation is obtained in shaker experiments with limited acceleration input. In the actual operation, the tangential accelerations as a result of the tire-road contact are estimated to supply power around 1 mW with our design, which is sufficient for powering wireless tire sensors