Absorption‐Dominant Electromagnetic Interference Shielding of Ti ₃ C ₂ T _x MXene‐Coated and Fe ₃ O ₄ ‐Integrated TPMS Composites with Coupled Gradient Conductivity and Size‐Graded Structure

The increasing endeavor toward advanced electronic technologies leads to ubiquitous emission of electromagnetic waves (EMWs). To mitigate electromagnetic pollution, it is vital to develop absorption-dominant EMI shields to stringently alleviate the secondary pollution caused by the highly conducting traditional shields. A functionally driven variable-cell size and coating triply periodic minimal surface (TPMS) structure was created to realize stepwise longitudinal gradient impedance. Absorption-dominant EMI shielding was achieved by coupling the intrinsic properties of Ti₃C₂T_x MXene coating with the benefits of a robust macrostructural graded TPMS structure. A gradient-conductive MXene-coated TPMS with a graded gyroid structure was fabricated via a hybrid process combining additive manufacturing and dip coating. In essence, the graded structure effectively orchestrates the journey of EMWs, first coaxing them inside and systematically draining its energy, resulting in superior EMI absorptivity within the X-band range. Such a configuration endowed the structure with absorption-dominant EMI shielding (absorptivity≈0.85) with an EMI SE_T of ≈ 59 dB, for 10 mm-thick composites. Further increasing the thickness to 20 mm achieved a higher EMI SE_T of 68.07 dB with an extraordinary absorptivity of approximately 0.96. The developed design exhibited temperature insensitivity, affirming its environmental stability over a wide range of temperatures between -80°C to 200^°C.