Bridging Biological Thermoregulation Strategies and Engineered Materials for Emerging Radiative Cooling Applications

Radiative cooling (RC) has emerged as a compelling energy-free solution for passive thermal management by dissipating heat into cold outer space through the atmospheric window. While recent advances have significantly optimized spectral performance, the field is now shifting toward the simultaneous realization of high solar reflectance, superior thermal emittance, long-term environmental durability, and scalable manufacturing under realistic service conditions. Natural organisms, having evolved sophisticated thermoregulatory strategies over millions of years, provide ideal blueprints for addressing these multi-objective challenges through the synergy of biological feature architectures and intrinsic material properties. This review systematically analyzes biological thermoregulation strategies and their underlying physical principles by categorizing natural archetypes into one-dimensional fibrous structures, two-dimensional surface gratings or scales, and three-dimensional porous networks or hierarchical architectures. We clarify how specific optical mechanisms are integrated within these biological architectures to achieve precise radiative control across the electromagnetic spectrum. Furthermore, the translation of these natural principles into engineered materials is discussed across diverse sectors, including personal thermal management and atmospheric water harvesting. By identifying persistent bottlenecks and future research trajectories, this review establishes a strategic framework for developing next-generation, bioinspired RC technologies capable of meeting global cooling demands with enhanced functional reliability and broad application potential.