Periodic Reporting for period 1 - ETERNAL (high-EfficienT piEzoelectRic vibratioN energy hArvester for raiL track system)
Reporting period: 2022-09-01 to 2025-08-31
Railway track and rolling stock interact with each other, forming a complex dynamic system which leads to structural degradation of railway assets with time, as such, pose a threat to not only safety, but comfortable rail operations. Modern ICT and sensing technologies could ensure a safe, secure and efficient transport network. However, greater connectivity and sensor coverage along tracks which require no mains power or batteries for energy supply, eliminating the costs for cabling and battery replacement, and minimum gateway installations, are critical for the success of industry adoptions. As such, the ETERNAL fellowship is providing a solution towards to the development of self-powered Internet-of-Things (IoT) devices for railway system by harvesting the vibration energy when the train travels. Through new, insightful laboratory investigations supported by numerical simulations, a vibration-based piezoelectric energy harvesting prototype is developed for the railway system. ETERNAL establishes inner links between the excitation source and the component natural frequency in rail track systems, and develops the piezoelectric ceramics by combining texturing process and multilayered structure together, which take the functionality (large output current, high energy density, low cost, and high mechanical strength) of the piezoelectric vibration energy harvester (PVEH) to the next level. This fellowship advances the underpinning technology for developing an energy harvester with the ultimate goal of developing self-powered IoT devices, which expected to transform rail track monitoring capability and ensure a more sustainable railway development in the 21st century, in the EU and internationally.
A triboelectric-electromagnetic-piezoelectric hybrid wind energy harvester (TEP-WEH) based on the cantilever is proposed. The TEP-WEH achieves a power density of 95.97 mW m-3∙rpm at a 3 m s-1 wind speed, attributable to a rational and optimized structural design. In addition, owing to the soft contact strategy of the TENG module, the TEP-WEH provides excellent durability and driveability. The harvester is demonstrated to successfully and continuously light a commercial lighting bulb rated at 5 W and provide an energy supply for self-powered sensing. This work provides an efficient solution for wind energy harvesting and wide-scale self-powered IoT sensing.
In November 2013 EU Commissioner Hahn urged regions to identify their key assets and focus resources on them to enhance their competitive advantage. Transport networks and in particular large rail earthwork infrastructure are significant resources. This project explores a potential to empower future generations of self-powered microelectronics for railway infrastructure health monitoring by harvesting the railway mechanical vibration energy. The direct impact from this fellowship: (1) develop pathways to transfer smart material to railway engineering; (2) make a great contribution to potentially lower the maintenance bill approximate €1.8bn from transport for automatic monitoring; (3) establish fundamental inner links between excitation source and the component natural frequency to optimize PVEH structure; (4) through project dissemination and outreach activities, the project will also develop awareness programs to improve public knowledge of energy harvesting and smart railway monitoring technologies; (5) drive the development of energy harvesting systems to empower future generations of self-powered microelectronics.