Ultrathin MXene/Ag-Ag nanocomposite films for 3D-conformal electromagnetic shielding via aerosol jet printing

Lightweight and ultra-thin conformal shielding films can be directly integrated on the surfaces of complex structures without occupying additional three-dimensional (3D) space, holding considerable promise for protecting sensitive precision electronic equipment. Here, titanium carbide/silver (MXene/Ag) nanocomposites were synthesized through electrostatic adsorption and in-situ self-reduction, and subsequently combined with Ag ink to create a MXene/Ag-Ag hybrid ink optimized for aerosol jet printing (AJP). The introduce of ethylene glycol based solvent system largely prevents the aggregation of aerosolized hybrid ink particles and reduce the overspray as well. This hybrid ink exhibited a printing resolution of ∼ 10 μm and excellent electrical stability, with only a 4.8 % increase in resistance of the printed trace after 1000 bending cycles. The internal pores and heterogeneous interfaces of MXene/Ag formed after sintering process significantly enhanced the electromagnetic wave absorption of the film. The specific electromagnetic interference (EMI) shielding effectiveness (SE) (SSE/t, defined as the ratio of EMI SE to the density and thickness) of the MXene/Ag-Ag film reaches 52591.4 dB·cm²/g at a thickness of merely 500 nm with only 0.9 mg weight increment. Simultaneously, the successful fabrication of high-quality conformal films on various complex substrates showcases the advanced manufacturing capabilities of AJP. Moreover, the utilization of the shielding film in practical applications, including electric field shielding, wireless charging, and near-field communication (NFC) interruption, highlights the potential of AJP technology for the fabrication of integrated conformal EMI shielding electronics with custom-designed structures.