Unlocking Dual-Mode Thermal Regulation and Electromagnetic Protection Strategy in Extreme Conditions via Bidirectional Janus Design

Abstract

Thermal regulation plays a significant role in maintaining human physiological homeostasis, yet conventional thermal management systems face limitations due to their unidirectional operation and insufficient adaptability in extreme environments. Herein, we design a novel bidirectional Janus structure (ACuAg films) integrating synergistically dual mode passive/active radiation heating for adaptive personal thermal management across extreme environmental conditions. The ACuAg film combines a high reflectance layer (0.9) with a high-emissivity surface (0.89) in two sides, achieving remarkable dual mode-switching capability through simply flipping. The detailed mechanism has been studied to demonstrate the outstanding passive/active radiation heating of ACuAg films to maintain the appropriate temperature of the human body. In addition, the excellent photothermal performance of the ACuAg films also provides another safeguard for human thermal management. Beyond thermal regulation ability, the films provide exceptional electromagnetic interference shielding (~53 dB), ensuring protection in challenging environments. With remarkable stability against harsh chemicals, extreme temperatures, and over 5,000 folding cycles, the ACuAg Janus films offer a robust solution for both thermal and electromagnetic protection in extreme conditions. In brief, this work unlocks a practical approach for dual-mode thermal regulation and electromagnetic protection for human body in extreme conditions via bidirectional Janus design.