Hierarchical Biomimetic Engineering of Transition Metal Dichalcogenide-Based Composites for Electromagnetic Attenuation: Structure-Behavior-Function Relationships and Design Rules

Transition metal dichalcogenide (TMD)-based composites are increasingly investigated for microwave absorption and electromagnetic interference shielding, yet their attenuation response cannot be explained by composition alone. The spatial arrangement of nanosheets, pores, interfaces, and conductive domains governs wave entry, polarization relaxation, carrier transport, and internal dissipation. Biomimetic materials are nevertheless commonly classified by their resemblance to flowers, nacre, honeycombs, or biological networks, making it difficult to compare structures that perform similar physical roles. Accordingly, a structure-behavior-function (SBF) relationship is used to reassess the field. TMDs are considered adjustable building units whose phase, defects, surface chemistry, and assembly can be tailored while restacking, limited conductivity, and structural instability remain practical constraints. Five recurring strategies are examined: porous architectures that modify wave propagation, heterogeneous interfaces that redistribute charge, oriented channels that direct carrier transport, through-thickness gradients that regulate impedance, and multilevel structures that couple these processes. Reported absorption and shielding results are compared to determine where these structural interpretations are supported and where commonly used descriptors, including filler loading, total porosity, and interface density, remain insufficient. The resulting design rules are function-dependent because high total shielding, strong microwave absorption, and absorption-dominated shielding require different balances among conductivity, polarization, and impedance matching. Quantitative descriptors, multiscale modeling, data-assisted design, reproducible manufacturing, and device-level validation are identified as priorities for moving biomimetic TMD composites beyond morphology-led optimization.