Hierarchical-morphology metafabric for scalable passive daytime radiative cooling

The fibers that make up textiles can be augmented to change how they interact with thermal radiation, but the resulting materials often are not durable. Zeng et al . developed a multilayer metafabric composed of a titanium oxide polylactic acid composite laminated with a polytetrafluoroethylene layer. This combination creates a textile that has passive radiative cooling properties with good mechanical properties and scalability. The textile can be made into clothes or car covers and keeps a person or a car much cooler than other fabrics. —BG Scalable multilayer fabric with hierarchical random structure provides daytime radiative cooling functionality. Incorporating passive radiative cooling structures into personal thermal management technologies could effectively defend humans against intensifying global climate change. We show that large-scale woven metafabrics can provide high emissivity (94.5%) in the atmospheric window and high reflectivity (92.4%) in the solar spectrum because of the hierarchical-morphology design of the randomly dispersed scatterers throughout the metafabric. Through scalable industrial textile manufacturing routes, our metafabrics exhibit desirable mechanical strength, waterproofness, and breathability for commercial clothing while maintaining efficient radiative cooling ability. Practical application tests demonstrated that a human body covered by our metafabric could be cooled ~4.8°C lower than one covered by commercial cotton fabric. The cost-effectiveness and high performance of our metafabrics present substantial advantages for intelligent garments, smart textiles, and passive radiative cooling applications.