Augmented Reality-Assisted Battery-Less Microwave-Based Sensors for Smart Health Monitoring of Coatings

Rapid infrastructure expansion and growing emphasis on smart sustainable cities, demand the need for reliable, real-time coating health monitoring (CHM) techniques to ensure mechanical stability and prevent safety hazards. This work presents a microwave-based CHM system consisting of a passive array of split ring resonator (SRR) sensor integrated with augmented reality, for real-time non-destructive coating damage inspection and enhanced visualization capabilities. The developed system operates by monitoring the variations in the resonant response of the SRR array, caused by the loss in coating thickness due to operational and environmental wear. The SRR array is layered with 0.3 mm thick film-like polyethylene-based coating and gradually eroded. The system demonstrates a resonant frequency increase of ~331 MHz upon the erosive wear of the coating. The integration of augmented reality with the developed system provides a real-time and intuitive visualization of the system response and its corresponding damage assessment, providing a significant low-cost solution in areas that are traditionally challenging to monitor. The developed system promises the potential of microwave-based sensing integrated with augmented reality-based visualization, in out-of-sight monitoring for applications including pipelines, aircraft, bridges, and naval infrastructure.