A layered metastructure-based smart radiant regulator with enhanced emissivity modulation utilizing phase change material

Based on thermal radiation, radiative cooling is a widely used technology, and plays an important role in many scenarios such as passive building cooling and infrared camouflage. Currently, dynamic control of thermal radiation devices is endowed with great expectations. However, a more efficient systematic strategy for designing smart radiant temperature regulators (SRTRs) is still urgently needed. By leveraging the phase change properties of vanadium dioxide, the proposed SRTR achieves dynamic modulation of thermal emissivity, demonstrating an average total directional emissivity exceeding 0.9 when the temperature is above the threshold temperature, and dropping below 0.1 when the threshold temperature is not been reached, particularly within the atmospheric transparent window band. The optimization results achieved by using Autonomous Particles Groups for Particle Swarm Optimization demonstrate better performance metrics compared to those obtained using conventional methods. Notably, the absorption mechanism of layered metastructure is further investigated, and its high angle dependency is effectively addressed. The demonstrates excellent angular stability and polarization insensitivity, with up to 73° in transverse electric mode and 60° in transverse magnetic one. Without taking non-radiative heat transfer into account, the cooling power achieves 214.59 W·m⁻². In this paper, a more systematic strategy for designing SRTRs is exhibited, which offers extensive potential in fields such as surface radiative cooling, infrared camouflage, and spacecraft thermal management.