Chainmail-inspired conformable and switchable microwave metamaterial absorber

Abstract The rigidity of conventional microwave absorbers impedes their reliable integration with complex curved surfaces and deformable components. However, these capabilities remain indispensable for electromagnetic stealth and miniaturized electromagnetic compatibility (EMC) applications that rely on advanced conformal wave-manipulation. To overcome these challenges, we present a chainmail-inspired conformal and switchable microwave metamaterial absorber, conveniently fabricated via 3D printing. The structure exhibits a broadband effective absorption bandwidth (EAB) from 6.2 to 17.6 GHz, while its interlocking topological design enables curvature adaptation without deformation of the absorbing parts. After conformal shaping, the average absorptivity decreases by only 0.049, demonstrating markedly enhanced robustness compared with conventional designs. Furthermore, we integrate the microwave absorber with elastic bands to achieve reversible switching between expanded and contracted states, extending the minimum operating frequency. The optimally configured design achieves a cumulative bandwidth (union of the EABs achieved at 24 cm and 27 cm configurations) from 4.6 to 18 GHz, circumventing the Rozanov limit through dynamic switching. This work provides a practical strategy for realizing switchable ultra-wideband conformal microwave absorbers in diverse electromagnetic applications.