Tunable\nHigh-Performance Electromagnetic Interference\nShielding of VO₂ Nanowires-Based Composite

Abstract

The\nunique metal–insulator transition of VO₂ is\nvery suitable for dynamic electromagnetic (EM) regulation materials\ndue to its sharp change in electrical conductivity. Here, we have\ndeveloped an off/on switchable electromagnetic interference (EMI)\nshielding composite by interconnecting VO₂ nanowires (NWs)\nin poly(vinylidene fluoride-<i>co</i>-hexafluoropropylene)\n(PVDF-HFP) to form conductive networks, resulting in outstanding performance\nat the X and Ku bands with maximum change values of 44.8 and 59.4\ndB, respectively. The unique insulator-to-metal transition (IMT) of\nVO₂ NWs has dominated the variation of polarization loss\n(ε_p″) and conductivity loss (ε_σ″) for the composites, which is the mechanism of EMI shielding\nswitching between off and on states. Furthermore, the composite exhibits\ngood cycling stability of the off/on switchable EMI shielding performance\nand has excellent mechanical properties, especially with 200 times\nabrasion resistance without obvious weight loss. This study provides\na unique approach for dynamic switching of EM response with the potential\nto construct practical intelligent EM response systems for next-generation\nsmart electromagnetic devices in various scenarios.