Dual-mode wireless integrated system for real-time monitoring and early warning of large-scale marine structures

Real-time monitoring and warning play a key role in the safety and maintenance of marine structures. However, traditional sensing systems are inadequate in realizing multi-directional monitoring of high-amplitude and low-frequency dynamic response of marine structures. Herein, we propose a dual-mode wireless integrated system based on the all-in-one 3D printed spiral-helical triboelectric nanogenerator (SH-TENG) that consist of the spiral component for X-Y axis wind load and helical component for Z-axis vehicles. We first characterize the SH-TENG for their mechanical and electrical properties (i.e., sensitivity and ductility) under different loading conditions. Next, the SH-TENG are integrated to a wireless system for high- and low-frequency dual-mode monitoring and early warning, including the data acquisition module to obtain and store real-time monitoring data, the wireless transmission module to transmit data via long distance (>10 km), and the assessing and warning module to analyze the data by the analytic hierarchy process (AHP) in a real-time manner. In practice, the dual-mode wireless integrated system is applied to the key structural components of a large-scale cross-sea bridge to obtain the comprehensive assessment of its overall service status. The reported dual-mode wireless integrated system provides novel design guidance for real-time monitoring and early warning of marine structures with complex multi-directional dynamic response.