Mimicking butterflies: Thermal adaptive management material with shape memory Janus arrays

The radiative heat management provides a zero-energy thermal regulation strategy. However, most thermal management materials are static and single-functional, failing to meet the practical requirements of dynamic cooling and heating. Here, inspired by the switchable asymmetric optical structure of butterfly, a temperature adaptive dual-mode management material (TADM) is proposed. TADM is composed of asymmetric shape memory Janus arrays that can reversibly transform between tilted and collapsed states, allowing for adaptive switching between cooling and heating modes in response to temperature fluctuations. In cold weather, the TADM exhibits low solar reflectivity (14.7%) and atmospheric transparency window emissivity (25.4%). When the surface temperature of TADM exceeds the phase transition temperature, it demonstrates a radiative cooling mode, with 90.3% solar reflectivity and 96.0% atmospheric transparency window emissivity. The results indicate that TADM enables superior multi-band and wide-amplitude intelligent optical control. Outdoor tests and energy consumption simulation have confirmed that TADM has excellent thermal management performance. This study provides valuable references for the application of shape memory Janus arrays in dynamic thermal management systems, as well as in the design of switchable intelligent biomimetic materials.