Herein, the electromagnetic shielding performance of surface concave-convex (SC) and zig-zag micro-arrays was studied by using a simulation prediction and a three-dimensional (3D) printing custom model. Firstly, surface stripe concave-convex (SSC) and surface cylindrical concave-convex (SCC) micro-arrays with or without zig-zag micro-arrays are designed, and their shielding performance is simulated in multi-bands (C-, X-band). The multiwalled carbon nanotubes/polydimethylsiloxane composites (MWCNT/PDMS) with different SC structures and different electrical conductivity are molded in acrylonitrile-butadiene-styrene copolymer (ABS) molds which are printed by a 3D printer. The results show that the electromagnetic interference shielding effectiveness (EMI SE) of the samples can be enhanced by constructing the SC micro-arrays with zig-zag micro-arrays, and improving with the increase of conductivity and frequency. In addition, the shielding mechanism of the SC-MWCNT/PDMS composites is investigated and discussed by an electromagnetic simulation.

Carbonized metallic organic frameworks (CMOF) have been attracting attention in microwave absorption (MA) research area because of their diverse structures, tunable compositions, and rich porosity. Herein, structure regulation on metal clusters in CMOF is achieved by tuning the interaction strength between metals and ligands to enhance microwave absorption performance. Due to relatively weak interaction among copper cations and ligands, copper nanoclusters (CuNC) can be uniformly formed and embedded within the cobalt/zinc (Co/Zn) CMOF. Firstly, copper cations are added to the Co/Zn bimetallic zeolitic imidazolate frameworks (ZIFs). Secondly, the CMOF composite particles with CuNCs (CuNCs/CoZn-CMOF) were developed by a pyrolysis process. The CuNCs/CoZn-CMOF with an appropriate amount of CuNCs can harmonize both dielectric and magnetic losses. As a result, the minimum reflection loss (RL_min) reaches –45.1 dB at a matching thickness of 2.30 mm and the effective absorption bandwidth (EAB) is 8.80 GHz at a thickness of 3.10 mm. The broadband response to electromagnetic waves is attributed to interfacial polarization at CuNCs surface and heterogeneous interfaces, impedance matching and multiple scattering of electromagnetic waves. This study provides a feasible method to develop CMOF microwave absorption materials with high EAB values.