Dynamically tunable electromagnetic wave absorbing materials: Stimuli-responsive modes and working principle

The emergence of electromagnetic wave absorbing materials represents a milestone in the battle against electromagnetic pollution. However, the performance of traditional absorbing materials is fixed upon fabrication, making it difficult to meet increasingly complex electromagnetic protection requirements. Consequently, the development of tunable absorbing materials, capable of dynamically adjusting their absorption performance in response to external stimuli, has become a major research focus. This work provides a comprehensive review of research on tunable absorbing materials, categorized by their response mechanisms. Based on the fundamental interaction between matter and energy in classical physics, the various stimuli-responsive modes are systematically classified and summarized. An in-depth analysis of design strategies, working principles, and recent research progress for each category of tunable absorbing materials is subsequently presented, along with a discussion of the advantages and challenges associated with different response mechanisms. Finally, the underlying mechanisms of tunable absorbing materials are summarized, and future development directions are outlined in light of emerging application needs. This work is expected to provide valuable insights and guidance for the rational design and application of next-generation intelligent electromagnetic protection materials.