Harnessing impedance matching and destructive interference: a modular asymmetric nanofibrous conductive network for tunable absorption-dominant EMI shielding

Addressing the challenge of achieving simultaneous high absorption and high electromagnetic interference shielding effectiveness (EMI SE), this work presents a modularly assembled alternative to Salisbury screens. The material is constructed on a modified electrospun TPU film with a designed three-layer architecture. The top layer is a CNTs-wrapped nanofiber porous network for impedance matching, the bottom is a silver-coated nanofiber network ensuring complete reflection, and a precisely tuned intermediate layer enhances destructive interference. This study systematically examines how the conductivity of the matching and bottom layers, along with interlayer thickness, govern overall EMI SE and absorption. The analysis reveals the optimal synergy between impedance matching and interference cancellation and clarifies the role of the conductive nanofiber network. The resulting composite, C5/T4/A3, achieves an EMI SE of 72.75 dB with only 0.04 wave reflection and a 3.40 GHz low-reflection bandwidth ( R < 0.1) covering 81% of the X-band. The simulated radar cross section value of the C5/T4/A3 simulated radar was the lowest within the wide θ range of -90° to -90°, and the peak decreases to -12.62 dBm 2 when θ = 0°. The replaceable bottom layer enables direct tuning of EMI SE by varying its conductivity, without changing the core mechanism. This work provides valuable guidance for designing absorption‑dominated, high‑performance EMI shielding materials.