Energy harvesting from carbon-based rope driven by capillary flow

Harvesting energy from the natural environment has garnered significant interest due to its eco-friendliness and spontaneity. Here, we present a novel carbon-based rope hydrovoltaic generator, fabricated by a straightforward dip-coating method. Water infiltrates the rope and flows driven by capillary forces, creating a wet/dry interface. An electrical double layer (EDL) forms at the carbon-water interface where wetting occurs, causing protons to accumulate between the wet and dry regions and establishing a substantial potential difference. Under environmental conditions, this setup can induce an open circuit voltage of approximately 0.4 V when a 0.01 mL droplet is applied to the carbon-based rope (with a resistance of 1 M Omega). As a proof of concept, the output performance can be scaled through series and parallel connections, successfully charging a 100 mu F capacitor that powers a digital calculator. This simple and flexible hydrovoltaic device provides a new method for clean energy harvesting in practical applications.