Experimental and Analytical Parametric Study of Single Crystal Unimorph Beams for Vibration Energy Harvesting

MA Karami (Virginia Tech, USA), O Bilgen (Swansea University), DJ Inman (Virginia Tech, USA) & MI Friswell (Swansea University)

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 58, No. 7, July 2011, pp. 1508-1520


This research presents an experimental and theoretical energy harvesting characterization of beam-like, uniform cross-section, unimorph structures employing single crystal piezoelectrics. Different piezoelectric materials, substrates and configurations are examined to identify the best design configuration for lightweight energy harvesting devices for low power applications. Three types of piezoelectrics (single crystal PMN-PZT, polycrystalline PZT-5A, and PZT-5H type monolithic ceramics) are evaluated in a unimorph cantilevered beam configuration. The devices have been excited by harmonic base acceleration. All of the experimental characteristics have been matched with exact electromechanical model of the harvester. The study shows the proper choice of substrate material for single crustal piezoelectric energy harvesting. To further optimize the power harvesting, we study the relation between the substrate-to-piezoelectric thickness ratio and the power output for different substrate materials. The relation between power and substrate thickness profoundly varies among different substrate materials. The variation is understood by examining the change of mechanical transmissibility of the harvesters with thickness ratio. By comparing the devices of various material and dimensions we identify the features of most productive energy harvester. After identifying the parameters in the model using the experimental results, we investigate energy harvesters with a broad range of design parameters and identify the optimal configurations.

Paper Availability

This material has been published in the IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 58, No. 7, July 2011, pp. 1508-1520, the only definitive repository of the content that has been certified and accepted after peer review. Copyright and all rights therein are retained by the IEEE.

Link to paper using doi: 10.1109/TUFFC.2011.1969

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