Bioinspired Temperature-Adaptive Thermal Management Membrane Based on Reversible Thermochromic Fibers for All-Season Thermal Regulation

Radiative heat-transfer-based thermal management techniques provide a zero-energy thermal regulation strategy. Various radiative thermal management materials with a dual-mode of cooling and heating have been developed for all-season thermal regulation. However, developing intelligent switching between the two modes is the most challenging issue. Inspired by the thermally induced color change of Siamese cat hair, we proposed a novel reversible thermochromic fiber membrane (RTFM) with temperature-adaptive dual-mode thermal management performance. The RTFM shows automatic switching between black and white in response to temperature fluctuations, leading to a significant change in the optical properties. Specifically, RTFM appears white, with high solar reflectance exceeding 90% and strong thermal emittance approaching 95% under high temperatures, thus demonstrating an efficient cooling mode. When the temperature drops below a certain threshold, RTFM turns black, resulting in a 30% increase in the solar energy absorption, thus presenting a heating mode. Due to the temperature-responsive optical properties, RTFM achieves a cooling effect of ∼3 °C on a hot sunny day and a heating effect of ∼2 °C on a cold cloudy day. Such scalable, durable, and flexible fiber membranes offer a novel approach for fabricating intelligent thermal management materials, demonstrating the significant potential for ensuring a comfortable environment for human beings.