Compatibility Challenges and Strategies of Multispectral Stealth Materials: From Microwave-Terahertz Absorption to Infrared Camouflage

The rapid advancement of radar detection and communication technologies, coupled with the increasing complexity of electromagnetic (EM) environments, has driven the demand for multispectral-compatible stealth materials that can function across microwave (MW), terahertz (THz), and infrared (IR) bands. This review systematically summarizes the recent progress in the design and development of ultrabroadband EM waves (EMWs) stealth materials. First, it clarifies the fundamental principle of achieving single-spectrum stealth and the inherent challenges of multi-spectrum compatibility, especially the contradictory requirements in different frequency bands. Designing multispectral compatible stealth materials requires a rational design of the multi-scale structure and composition at both macro/micro level and atomic/molecular level. Subsequently, an analysis of the state-of-the-art materials and structures, such as aerogels, multilayer composites, and macroscopic metamaterials, is carried out. Particular emphasis is placed on heterogeneous interface engineering, gradient design, bioinspired concepts, and intelligent responsive systems. Ultimately, potential solutions, including deepening the understanding of the loss mechanism and machine learning-assisted material design, are presented to develop multifunctional, adaptive stealth systems. This review aims to provide valuable insights and inspiration to researchers in next-generation multispectral-compatible stealth technologies.