Multi-scale integrated design and fabrication of ultrathin broadband microwave absorption utilizing carbon fiber/Prussian blue/Fe₃O₄-based lossy lattice metamaterial

Microwave absorption materials (MAMs) are specialist kinds of composites applied in stealth technology and electromagnetic interference (EMI). However, it is tough to satisfy the ultrathin and broadband requirements due to the imperfect impedance matching with external air and single absorbing fillers. Herein, a lower concentration of short carbon fiber (SCF)/Prussian blue (PB)/Fe3O4/epoxy resin (EP)-based butterfly-scale metamaterial (BSM) absorber with ultrathin and broadband was achieved via integrated design and fabrication. This revealed that the synergic effect between the SCF/PB/Fe3O4/EP MAMs with dielectric-magnetic behavior and physical resonance loss of the periodic unit for the BSM absorber is profitable for improving the electromagnetic absorption performance. Furthermore, the integrated fabrication process completely avoided the interface effect in traditional metamaterials. As a result, the proposed BSM absorber exhibited an absorption bandwidth of 29.54 GHz below -9.5 dB (>88.7% absorption) under TE = 0° polarization in the 2-40 GHz frequency range and 35 GHz below -9.5 dB under TM = 50° polarization. Analysis of the micro- and macro-absorption mechanism implied that the magnetic loss mainly resulted in power loss compared with dielectric loss. This highlights that the BSM absorber is an appropriate candidate for further practical applications, such as communication devices and military equipment.