Recent Advances of Bio-inspired Radiative Cooling Films Design in Sustainable Building Applications

Abstract

Amid escalating global warming, radiative cooling technology has emerged as a transformative approach to sustainable building cooling and energy efficiency. Conventional inorganic non-metallic and polymer-based radiative cooling films, however, face intrinsic limitations including suboptimal cooling performance, poor environmental durability, and inferior optical selectivity. Recently, several promising candidates, such as carbon compounds, metamaterials, and hydrogels, have been regarded as favorable radiative cooling materials, and these works are made great contributions to the development of the green building domain. However, the search for high-performance materials that can achieve a superior cooling effect still requires exploration. Nature offers inspiration: diverse organisms employ sophisticated micro-nano architectures for thermoregulation, motivating bio-inspired design paradigms in radiative cooling film development. However, systematic reviews of the scientific advancements and characteristics of bio-inspired radiative cooling films are still rare. To fill this knowledge gap, this review systematically examines‌ the operational mechanisms of radiative cooling techniques, ‌identifies critical limitations of conventional film materials‌, and ‌evaluates recent advancements in bio-inspired design strategies for radiative cooling films‌. Finally, the perspectives of bio-inspired radiative cooling films are discussed in detail.