ELF/VLF Electromagnetic Interference Shielding by Low‐Dimensional Conductors Embedded in Insulating Polymer Matrices

Abstract The interaction of very low frequency (VLF) and extremely low frequency (ELF) electromagnetic waves with nanocomposites is rarely explored. It is demonstrated that low‐dimensional electrically conducting fillers are able to shield extremely long wavelengths, provided they form extended conduction paths through percolation. Other mechanisms that synergistically augment the shielding of the high frequencies, such as skin effect, interfacial polarization, and multiple internal scattering, have insignificant effects in the low‐frequency range. In this regard, high aspect ratio 1D conductors having the lowest percolation thresholds provide the best shielding performance, both gravimetrically and volumetrically. Shielding in these materials are observed majorly occur mostly through reflection, and hence, these materials can be employed for both shielding and guiding low frequencies. The correlation proposed to estimate shielding effectiveness based on conductivity and frequency enables convenient material design for low‐frequency modulation.