Uncovering internal water-flux and surface-potential dominance in hydrogel-based moisture-enabled power generation: mechanistic insights and performance enhancement

modification increased the surface potential difference by 111.5 mV, improving the output by 30-50% and enabling sustained power under continuous water flow. Surface evaporation contributes solely by sustaining water flux, whereas triboelectric and streaming potential effects are negligible. This work establishes a quantitative mechanistic framework and delivers clear design principles for robust, high-efficiency MEGs, paving the way for self-powered sensors, portable electronics and distributed energy-harvesting platforms.