Bioinspired Rhombic VO₂ Metasurface with Low Solar Absorptance for Self-adaptive All-Weather Building Thermal...

Passive radiative cooling effectively reduces energy consumption but often suffers from winter overcooling. To address this challenge, we report a bioinspired rhombic-patterned vanadium dioxide (VO₂) metasurface intelligent thermal radiative device (RITD) for self-adaptive all-weather building thermal regulation. Through tailoring of the synergistic coupling between the metal-insulator transition (MIT) of VO₂ and the multiple resonances of a Fabry-Pérot (F-P) cavity and subwavelength periodic VO₂ arrays, the RITD achieves a dynamic emittance modulation (Δε) of 0.65 (from 0.27 to 0.92) within the atmospheric transparency window (8-14 μm). Crucially, the bioinspired architecture maintains a stable, low solar absorptance (α_sol = 0.23), effectively suppressing excessive solar heating and thus maximizing the net cooling power during intense sunlight exposure. With a tungsten-doped tunable phase-transition threshold (25-68 °C), the RITD demonstrates a daytime subambient cooling of ∼14 °C and a nighttime heat retention of ∼3 °C above the ambient temperature. Building energy simulations across multiple Chinese cities reveal that RITD-integrated roofs deliver substantial annual energy savings by simultaneously addressing cooling demands in summer and insulation needs in winter. This mechanism-driven design provides a scalable and robust strategy for advancing zero-energy buildings and sustainable thermal management technologies.