Hybrid Metamaterial Textiles for Passive Personal Cooling Indoors and Outdoors

Radiative cooling engineering generally utilizes thermal radiation and sunlight reflection to decrease the temperature of an object or space. In this work, a polymer-based nanophotonic textile (PBNT) based on radiative cooling was fabricated and possesses high spectral selectivity (eta = 5.12), IR absorbance/emittance (epsilon(AW)= 87.31%), and sunlight reflectance (rho = 93.28%). Indoor cooling measurement shows that the skins covered with the PBNT are 3.1-3.5 degrees C lower than traditional textiles. Under direct solar irradiation, the PBNT also exhibits a high cooling capability with skin temperatures 7.7-10.8 degrees C lower in contrast with traditional textiles. More critically, we successfully designed hydrophilic-hydrophobic Janus surfaces so that the metamaterial possesses both wonderful antifouling and moisture permeability properties. Such excellent thermal and wearable properties demonstrate the promising perspective of the PBNT for summer textiles.