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

Abstract

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.