Self-powered swimming motion monitoring using a single-wire structure triboelectric nanogenerator

Wearable sensors for swimming safety monitoring have attracted growing interest due to the need for real-time and reliable tracking in aquatic environments. Here, we present a single-wire triboelectric nanogenerator (SW-TENG) integrated into a life jacket for self-powered swimming safety monitoring. The SW-TENG is composed of a large silicone tube coated with copper paint and a smaller silicone tube wrapped around a single wire, forming a flexible structure suitable for underwater operation. The device delivers a peak voltage of 57.2 V, transferred charge of 30.1 nC, and current of 3.5 μA under 25 N load at 2 Hz. When embedded into a swimsuit, it enabled sensitive multi-joint motion tracking and distinguished among various swimming behaviors. With wireless data transmission, the system provides real-time, self-sustained monitoring crucial for swimmer safety and performance evaluation. This work demonstrates the potential of SW-TENG technology for intelligent aquatic safety systems and rapid rescue applications.