Flexible Multilayer Combining Nickel Nanowires and Polymer Films for Broadband Microwave Absorption

In front of electromagnetic (EM) pollution of the environment, EM protection requires more and more efficient solutions. Multilayered films consisting of alternating stacked nickel nanowires (NWs)-based conductive layers separated by bulk polycarbonate films were fabricated as thin electromagnetic shield. The well-defined periodic arrangement of the multilayer structure with gradient NW concentration in the conductive layers demonstrates a remarkably high effective microwave absorption (reflection and transmission below $-$ 10 dB, up to 34.3 dB of absorption loss) by tuning the conductivity and magnetic permeability of each layer. The ferromagnetic nature of NWs enhances the absorption performances compared to nonmagnetic carbon nanotubes having similar conductivity. Our method provides a simple, compact, and efficient approach for the fabrication of electromagnetic interference shielding materials offering improved broadband microwave absorption.