• Utilising Nonlinear Air Damping as a Soft Mechanical Stopper for MEMS Vibration Energy Harvesting

      Chen, Shao-Tuan; Du, Sijun; Arroyo, Emmanuelle; Jia, Yu; Seshia, Ashwin A.; University of Cambridge; University of Chester (IOP Publishing, 2016-12-06)
      This paper reports on the theory and experimental verification of utilising air damping as a soft stopper mechanism for piezoelectric vibration energy harvesting to enhance shock resistance. Experiments to characterise device responsiveness under various vibration conditions were performed at different air pressure levels, and a dimensionless model was constructed with nonlinear damping terms included to model PVEH response. The relationship between the quadratic damping coefficient ζ n and air pressure is empirically established, and an optimal pressure level is calculated to trade off harvestable energy and device robustness for specific environmental conditions.
    • Vibration Energy Harvesting of Multifunctional Carbon Fibre Composite Laminate Structures

      alsaadi, Ahmed; University of Chester
      A sustainable power supply for a wide range of applications, such as power- ing sensors for structural health monitoring and wireless sensor nodes for data transmission and communication used in unmanned air vehicles, automobiles, renewable energy sectors, and smart city technologies, is targeted. This pa- per presents an experimental and numerical study that describes an innovative technique to harvest energy resulted from environmental vibrations. A piezo- electric energy harvester was integrated onto a carbon fibre reinforced polymer (CFRP) laminate structure using the co-curing method. The integrated com- posite with the energy harvester was lightweight, flexible and provided robust and reliable energy outcomes, which can be used to power different low-powered wireless sensing nodes. A normalised power density of 97 μW cm −3 m −2 s 4 was obtained from resonance frequency of 46 Hz sinusoidal waves at amplitude of 0.2 g; while the representative environmental vibration waves in various appli- cations (aerospace, automotive, machine and bridge infrastructure) were ex- perimentally and numerically investigated to find out the energy that can be harvested by such a multifunctional composite structure. The results showed the energy harvested at different vibration input from various industrial sectors could be sufficient to power an autonomous structural health monitoring system and wireless communications by the designed composite structure.
    • Vibration energy harvesting of multifunctional carbon fibre composite laminate structures

      Alsaadi, Ahmed; Shi, Yu; Pan, Lei; Tao, Jie; Jia, Yu; University of Chester; Nanjing University of Aeronautics and Astronautics
      A sustainable power supply for a wide range of applications, such as powering sensors for structural health monitoring and wireless sensoring nodes for data transmission and communication used in unmanned air vehicles, automobiles, renewable energy sectors, and smart city technologies, is targeted. This paper presents an experimental and numerical study that describes an innovative technique to harvest energy resulted from environmental vibrations. A piezoelectric energy harvester was integrated onto a carbon fibre reinforced polymer (CFRP) laminate structure using the co-curing method. The integrated composite with the energy harvester was lightweight, flexible and provided robust and reliable energy outcomes, which can be used to power different low-powered wireless sensing nodes. A normalised power density of 97  μW cm−3m−2s4 was obtained from resonance frequency of 46 Hz sinusoidal waves at amplitude of 0.2 g; while the representative environmental vibration waves in various applications (aerospace, automotive, machine and bridge infrastructure) were experimentally and numerically investigated to find out the energy that can be harvested by such a multifunctional composite structure. The results showed the energy harvested at different vibration input from various industrial sectors could be sufficient to power an autonomous structural health monitoring system and wireless communications by the designed composite structure.
    • A vibration powered wireless mote on the Forth Road Bridge

      Jia, Yu; Yan, Jize; Feng, Tao; Du, Sijun; Fidler, Paul; Soga, Kenichi; Middleton, Campbell; Seshia, Ashwin A.; University of Chester; University of Cambridge (IOP Publishing, 2015-12-01)
      The conventional resonant-approaches to scavenge kinetic energy are typically confined to narrow and single-band frequencies. The vibration energy harvester device reported here combines both direct resonance and parametric resonance in order to enhance the power responsiveness towards more efficient harnessing of real-world ambient vibration. A packaged electromagnetic harvester designed to operate in both of these resonant regimes was tested in situ on the Forth Road Bridge. In the field-site, the harvester, with an operational volume of ~126 cm3, was capable of recovering in excess of 1 mW average raw AC power from the traffic-induced vibrations in the lateral bracing structures underneath the bridge deck. The harvester was integrated off-board with a power conditioning circuit and a wireless mote. Duty- cycled wireless transmissions from the vibration-powered mote was successfully sustained by the recovered ambient energy. This limited duration field test provides the initial validation for realising vibration-powered wireless structural health monitoring systems in real world infrastructure, where the vibration profile is both broadband and intermittent.