Thermally responsive VO2-coated carbon fiber paper with dynamically tunable electromagnetic interference shielding performance

Intelligent electromagnetic interference (EMI) shielding materials with dynamically adjustable performance are highly desirable for applications in complex electromagnetic environments, especially in the 5G era. However, achieving a synergistic integration of stimulus-responsive mechanisms and practical activation methods remains challenging. Herein, a hybrid paper composed of carbon fibers coated with vanadium dioxide (CF@VO 2 ) was fabricated via hydrothermal synthesis and paper wet-papermaking processes, using PMIA as a matrix. Leveraging the reversible metal-insulator transition (MIT) of VO 2 at ∼64.7 °C, the CF@VO 2 paper exhibits efficient electric heating capability of rapidly heating to 120 °C at a voltage of 12 V within 100 s, enabling tunable electrical conductivity between ∼311 and ∼509 S/m and reversible total EMI shielding effectiveness (SE T ) between ∼23 and ∼33 dB in X band. The temperature-driven MIT realized by electric-heating changes the conductivity and current transport path of CF@VO 2 papers, leading to stronger conductive loss and interfacial polarization loss of the heterointerface formed by the CF coated with tetragonal phase VO 2 heterostructure (CF@VO 2 (R)), exhibiting a variable electromagnetic shielding effectiveness range of ∼10 dB and conductivity range of ∼198 S/m. This work demonstrates a feasible strategy for designing intelligent EMI shielding materials with promising applications in adaptive signal regulation and advanced electronic packaging.