Science Daily July 11, 2023
Despite intensive efforts invested, high-efficacy, all-season temperature regulation on real-world objects has not yet been achieved through truly passive, reliable structures. Researchers in China proposed and experimentally realized a Janus thermal cloak (JTC) composed of an all-ceramic, radiative-cooling phononic metafabric facing the sky and a photon-recycling foil facing indoor space. The phononic metafabric, which supports broadband hyperbolic phonon polaritons (HPhPs) and strong scattering of phonon transport, showed resilience under harsh thermal, mechanical, and corrosive environments. Field tests on electric vehicles showed that the JTC realized daytime sub-ambient cooling by 8.0°C in summer and nighttime supra-ambient warming by 6.8°C in winter. According to the researchers the JTC does not involve dynamic phase change or moving parts and thus is promising toward practical applications in buildings, vehicles, and extraterrestrial environments… read more. Open Access TECHNICAL ARTICLEÂ
Graphical abstract. Credit: Device, Available online 11 July 2023, 100008