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

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

Scalable Bio-Skin-Inspired Radiative Cooling Metafabric for Breaking Trade-Off between Optical Properties and Application Requirements

Passive daytime radiative cooling (PDRC) provides a zero-energy cooling technology to reduce the global fossil energy consumption and has already attracted tremendous interest. However, breaking the trade-off between the pursuit of ultrahigh dual-band (solar and atmospheric window) optical properties and the compatibility of multiple functional requirements by application is still a big challenge for PDRC. By introducing the photon slab-porous effect with strong sunlight backward scattering and inspired by human skin (epidermis and dermis) with recorded medical infrared emittance and multi-functions, we proposed an efficient dual-band optical property design strategy for PDRC. Through a simple and scalable dip dyeing process, the fabricated bio-skin-inspired PDRC metafabric exhibited superior dual-band optical properties, while both the solar reflectance and atmospheric window emittance can reach 97%. Outdoor tests demonstrated that the bio-PDRC metafabric achieved a maximum sub-ambient temperature drop of 12.6 °C in daytime. A human wearing a hat made of bio-PDRC metafabric can be 16.6 °C cooler than the one wearing a common hat. The bio-PDRC metafabric also exhibited superior performance of breathability, waterproofness, flexibility, strength, and durability to fulfill the multiple demands of personal thermal management, vents, and car covers

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

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

Scalable Bio-Skin-Inspired Radiative Cooling Metafabric for Breaking Trade-Off between Optical Properties and Application Requirements

Passive daytime radiative cooling (PDRC) provides a zero-energy cooling technology to reduce the global fossil energy consumption and has already attracted tremendous interest. However, breaking the trade-off between the pursuit of ultrahigh dual-band (solar and atmospheric window) optical properties and the compatibility of multiple functional requirements by application is still a big challenge for PDRC. By introducing the photon slab-porous effect with strong sunlight backward scattering and inspired by human skin (epidermis and dermis) with recorded medical infrared emittance and multi-functions, we proposed an efficient dual-band optical property design strategy for PDRC. Through a simple and scalable dip dyeing process, the fabricated bio-skin-inspired PDRC metafabric exhibited superior dual-band optical properties, while both the solar reflectance and atmospheric window emittance can reach 97%. Outdoor tests demonstrated that the bio-PDRC metafabric achieved a maximum sub-ambient temperature drop of 12.6 °C in daytime. A human wearing a hat made of bio-PDRC metafabric can be 16.6 °C cooler than the one wearing a common hat. The bio-PDRC metafabric also exhibited superior performance of breathability, waterproofness, flexibility, strength, and durability to fulfill the multiple demands of personal thermal management, vents, and car covers