Bioinspired Radiative Cooling Materials: From Design Principles to Building Energy Savings

Accounting for over one-third of global energy use, buildings face a rapidly rising cooling demand driven by expanding floor areas and extensive air-conditioning, making them a major source of global energy consumption and carbon emissions. Radiative cooling (RC) materials offer a promising route to address the conflict between global decarbonization goals and energy-intensive cooling demands through zero-energy, eco-friendly building temperature regulation. However, their practical adoption is still hindered by the unique functional demands of different building components. To address these site-specific requirements, natural organisms guide the rapid development of bioinspired RC materials. Herein, we review recent advances in bioinspired RC materials for building energy savings spanning from material design to practical applications. First, we discuss the design of static and dynamic RC materials from the perspective of bioinspired structural design and material selection. Then, we introduce the specific requirements of RC materials in practical building applications, such as mechanical durability and self-cleaning capability for roofs, angle-selective design and thermal insulation for walls, and transparency and adaptability for windows. Next, we summarize the performance assessment of RC materials, covering both basic optical metrics and building-specific evaluations. Later, we present the discovery and structural design of RC materials driven by machine learning. Finally, we outline the path forward for RC materials, such as intelligent integration with other cooling methods, addressing the key challenges and prospects for their real-world building applications.