Solar‐Mechano Symbiosis Dual‐Mode Janus Bioaerogel for Context‐Adaptive Atmospheric Water Harvesting Beyond Solar Reliance

Abstract Solar‐driven sorption‐based atmospheric water harvesting (SS‐AWH) offers promise for addressing global freshwater scarcity. However, the SS‐AWH heavily relies on favorable and sustained solar irradiation; yet real‐world solar irradiation exhibits significant spatiotemporal fluctuations, limiting its sustainable application, as non/low‐light conditions sharply reduce water productivity. This constraint is fundamentally due to the singleness of the water release pathway via photothermal desorption. Here, a novel dual‐mode bio‐based Janus aerogel (DBJA) is presented, enabling efficient, all‐weather, multi‐scenario atmospheric water harvesting via selectively solar‐driven and compression‐activated water release. The Janus structure optimizes mass/heat transfer between hygroscopic and photothermal domains, achieving the most balanced adsorption–desorption kinetics and compression‐recovery strength for solar‐mechano symbiosis. Under favorable sunlight, DBJA demonstrates a competitive water release efficiency of 1.32 g g −1 day −1 outdoors. Crucially, without solar irradiation, DBJA achieves a total water productivity of 12.80 g g −1 over 5‐cycle adsorption‐compression with 98% volume recovery and is stable within 50 cycles. Enhanced physical inlay and multiple chemical interactions ensure limited leakage of Li + ions during compression, and the collected water easily conforms to the World Health Organization (WHO) drinking water standards. This work provides a flexible approach for sustainable atmospheric water harvesting beyond solar reliance through multi‐mode synergy and gradient architecture.