A highly-sensitive wave sensor based on liquid-solid interfacing triboelectric nanogenerator for smart marine equipment

Wave monitoring is essential for marine engineering construction, development and utilization of ocean resources, maritime safety and early warning of marine disasters. In this paper, a highly-sensitive wave sensor based on liquid-solid interfacing triboelectric nanogenerator is proposed and systematically investigated. The wave sensor is made of a copper electrode covered by a poly-tetra-fluoroethylene film with microstructural surface. The effects of substrate, wave height, frequency, and water salinity on the performance of wave sensor are systematically investigated. It is found that the output voltage increases linearly with wave height with a sensitivity of 23.5 mV/mm for the electrode width of 10 mm, implying that the wave sensor could sense the wave height in the millimeter range. The sensitivity could be further increased by widening the electrode and/or enhancing the surface hydrophobicity. In a water wave tank, the wave sensor is successfully used to monitor wave around a simulated offshore platform in real time. Therefore, the novel wave sensor could provide an alternative to monitor wave for smart marine equipment.