PEDOT:PSS Conductive Networks Encapsulated within a Thermally Responsive VO₂ Nanoparticle/Cellulose Nanofiber Matrix for Electrothermally Triggered Dual-Mode EMI Shielding and Smart Electromagnetic Management

Increasing complexity in electromagnetic (EM) environments demands electromagnetic interference (EMI) shielding materials capable of dynamic performance modulation, as static solutions fail to meet evolving requirements. Stimuli-responsive materials hold promise, but their development is constrained by the trade-off between high baseline shielding effectiveness (SE) and broad tunability in dielectric-conductive composites. Herein, we present a multiscale structural engineering strategy that integrates component optimization with a stratified architecture to overcome this limitation. A smart EM device was realized by incorporating poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) conductive networks within a thermally responsive vanadium dioxide matrix, enabling synergistic electrical–thermal modulation in a hybrid thin-film system. The designed EM device exhibits dual-mode EMI shielding via an electrothermally triggered transition. Specifically, the engineered smart device demonstrates a substantial modulation in EMI shielding effectiveness (ΔSE = 18 dB), transitioning from a state of high absorption (SE = 10 dB, absorption coefficient A ∼ 0.4) to a reflective state (SE = 28 dB, reflection coefficient R ∼ 0.8). While maintaining rapid response (2 s) and cyclic stability. This work establishes a materials design paradigm for adaptive electromagnetic protection systems, demonstrating the viability of hybrid dielectric-conductive composites for intelligent EMI management in next-generation reconfigurable electronics.