Structure–Activity Relationship in Microstructure Design for Electromagnetic Wave Absorption Applications

Microwave absorbing materials (MAMs) are materials that effectively absorb incident electromagnetic (EM) wave energy, reducing reflection and scattering. They play a crucial role in enhancing electronic reliability, healthcare, and defense security. However, traditional MAMs like ferrites, magnetic metals, and polymers possess certain limitations, including low impedance matching, narrow absorption bandwidth, poor chemical stability, and high filling ratio, which hinder their further development. To address the requirements of lightweight, wideband, and high‐efficiency absorption, precise structural design has emerged as a captivating research focus. Additionally, comprehending the structure – property relationships between these unique microstructures and EM response and loss mechanisms still poses significant challenges. Herein, a comprehensive review of MAMs is presented with varied structural designs encompassing various scales, providing a detailed introduction of the relationship between various potential structural designs of MAMs and their corresponding EM characteristics and loss mechanisms. Moreover, EM theoretical calculation models, characterization, and analysis methods are discussed. Finally, the article proposes the challenges and prospects for the development of structural design EM wave absorbers.