Continuous Energy Harvesting from Ubiquitous Humidity Gradients using Liquid‐Infused Nanofluidics

Abstract Humidity‐based power generation that converts internal energy of water molecules into electricity is an emerging approach for harvesting clean energy from nature. Here it is proposed that intrinsic gradient within a humidity field near sweating surfaces, such as rivers, soil, or animal skin, is a promising power resource when integrated with liquid‐infused nanofluidics. Specifically, capillary‐stabilized ionic liquid (IL, Omim⁺Cl^‐) film is exposed to the above humidity field to create a sustained transmembrane water‐content difference, which enables asymmetric ion‐diffusion across the nanoconfined fluidics, facilitating long‐term electricity generation with the power density of ≈12.11 µW cm^‐2. This high record is attributed to the nanoconfined IL that integrates van der Waals and electrostatic interactions to block movement of Omim⁺ clusters while allowing for directional diffusion of moisture‐liberated Cl⁺. This humidity gradient triggers large ion‐diffusion flux for power generation indicates great potential of sweating surfaces considering that most of the earth is covered by water or soil.