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The lack of strong binding mechanism between nanomaterials severely restricts the advantages of evaporation‐driven hyhrovoltaic effect in wearable sensing electronics. It's a challenging task to observably improve the mechanical toughness and flexibility of hyhrovoltaic devices to match the wearable demand without abandoning the nanostructures and surface function. Here, we developed a flexible tough PAN/Al2O3 hydrovoltaic coating with both good electricity generation (open circuit voltage∼3.18 V) and sensitive ion sensing (2285 V M−1 for NaCl solutions in 10−4‐10−3 M) capabilities. The porous nanostructure composed of Al2O3 nanoparticles is firmly locked by the strong binding effect of PAN, giving a critical binding force 4 times than that of Al2O3 film to easily deal with 9.92 m s−1 strong waterflow impact. Finally, skin‐tight and non‐contact device structures were proposed to achieve wearable multifunctional self‐powered sensing directly using sweat. The flexible tough PAN/Al2O3 hydrovoltaic coating breaks through the mechanical brittleness limitation and broadens the applications of evaporation‐induced hydrovoltaic effect in self‐powered wearable sensing electronics.This article is protected by copyright. All rights reserved

Solar-driven vapor generation technology can directly produce clean water, but existing strategies remain challenging in achieving both high evaporation performance and good salt resistance due to complex water-thermal management.Here, we constructed hydrogel-based hierarchically nanostructured evaporator (HNE) with vertically aligned micro water transportation pathways and water confined ion selective nanochannels. Based on the polarity modified hierarchical structures and umbrella-shaped geometry design, HNEs can achieve highspeed water transfer at low saturated water content to realize efficient heat energy confinement, and provide more heat exchange sites. Consequently, an exciting water evaporation rate of 3.68 kg m À2 h À1 and the efficiency of 91.1% were achieved under 1 sun solar radiation. More importantly, the overlapping electrical double layer in the narrow nanochannels endows the ions selectivity of the nanochannel to reject anions, resulting in reliable long-term salt resistance. The ingenious design was creatively confirmed by streaming potential and validated during long-term efficient work.