Biomimetic, Robust, Recyclable Radiative Cooler via Water-Triggered Multistage Self-Assembly Toward Sustainable Agriculture

Passive radiative cooling is an emerging strategy for thermal management, yet conventional petroleum-derived coolers suffer from limited cooling performance and poor mechanical robustness, while inorganic alternatives, though efficient, require complex and energy-intensive fabrication. Inspired by the rapid formation and exceptional strength of spider silk, we develop a simple water-triggered multistage self-assembly strategy to fabricate a robust, recyclable, and eco-friendly bioinspired radiative cooler (Biocooler). The Biocooler exhibits high solar reflectance (0.94) and emittance (0.91), yielding an average temperature reduction of 8 °C under direct sunlight. Additionally, it possesses a tensile strength of 76 MPa, surpassing most conventional radiative coolers, and enables over 90% material recovery via water-triggered reassembly. As a soil mulch, the Biocooler reduces soil temperature by 7.2 °C and improves water retention by 61%, effectively mitigating crop heat stress. With its scalable production and durability, the Biocooler offers significant promise for sustainable agriculture applications.