"Warm in Winter and Cool in Summer": Scalable Biochameleon Inspired Temperature-Adaptive Coating with Easy Preparation and Construction.

Dong, Yan; Meng, Weifeng; Wang, Fuqiang; Han, Han; Liang, Huaxu; Li, Xiang; Zou, Yanan; Yang, Chun et al. · Nano Lett · 2023

basic_science · Level V

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Abstract

The highly reflective solar radiation of passive daytime radiative cooling (PDRC) increases heating energy consumption in the cold winter. Inspired by the temperature-adaptive skin color of chameleon, we efficiently combine temperature-adaptive solar absorption and PDRC technology to achieve "warm in winter and cool in summer". The temperature-adaptive radiative cooling coating (TARCC) with color variability is designed and fabricated, achieving 41% visible light regulation capability. Comprehensive seasonal outdoor tests confirm the reliability of the TARCC: in summer, the TARCC exhibits high solar reflectance (∼93%) and atmospheric transmission window emittance (∼94%), resulting in a 6.5 K subambient temperature. In the winter, the TARCC's dark color strongly absorbs solar radiation, resulting in a 4.3 K temperature rise. Compared with PDRC coatings, the TARCC can save up to 20% of annual energy in midlatitude regions and increase suitable human hours by 55%. With its low cost, easy preparation, and simple construction, the TARCC shows promise for achieving sustainable and comfortable indoor environments.