Broadband thermal management using smart cooling films

Abstract With the escalating trend of climate change, we are under severe pressure to increase the resilience of commercial and residential buildings and vehicles. Smart lighting and thermal management of windows promise to improve indoor thermal comfort with minimum added carbon footprints. We report a passive smart cooling technology for thermal management throughout the spectrum from visible to mid-infrared regions by using a thermochromic hydrogel network integrated with an optically transparent coating for radiative cooling, where excellent optical properties of luminous transmittance (81.8%) and solar transmittance modulation (74.8%) are achieved to intelligently minimize direct solar radiation, and emissivity of 0.999 in atmospheric transmission window contributes to extra radiative cooling power. Our design displays a thermo-responsive light reflection mechanism with compelling advances in moldability, mechanical flexibility, compatibility to base structures (e.g., glass roofs of cars), ease of manufacture and adoption, which are of practical significance towards real-world applications.