Optimization design and experimental investigation of piezoelectric energy harvesting devices for pavement

This study designs a compression-based pavement energy harvesting device with a group of piezoelectric transducers and investigates the selection of the component materials based on four technical device requirements for enhanced the electric energy output of power-generation pavements. The external dimensions of the proposed devices are optimized based on vehicle wheelpath distribution, tire trace patterns, and vehicle roller compaction conditions. The array pattern of the piezoelectric device is designed based on the driving characteristics. Various device material configurations are examined using different cover plates, rubber pad thicknesses, protective pads, and transducer specifications for optimal mechanic-electric response characteristics. A 150 mm × 150 mm type device is tested as an example and its electrical output performance is evaluated under typical road loading environments. Subsequently, a comparative analysis of various disclosed piezoelectric harvesting device technology were conducted and further research plan was developed. The selected modified polypropylene or aluminum plate, steel plate, modified polypropylene bar, and fiber heat insulation plate are suitable for the device which meets the application demands. The optimum device dimensions under light and heavy traffic conditions are 100 mm × 100 mm and 150 mm × 150 mm, respectively. The optimum configuration of the device includes a modified polypropylene upper cover plate, 1 mm rubber pad, ball-type protective pad, and eight laminated transducers. In addition, parallel connection of stacked transducers is more suitable for energy collection and reuse from traffic-induced pavement vibrations. Under the loading of 0.7 MPa and 15 Hz, the 150 mm × 150 mm device with nine parallel transducers achieves a maximum output power of 50.41 mW, and the corresponding optimum loading is 4 kΩ. Under the loading of 0.2 MPa and 10 Hz, the device achieves a maximum output power of 2.92 mW, and the corresponding optimum load is 10 kΩ. The performance of piezoelectric device designed in this paper excels that of many other available devices.