3D-Printed Pyramidal Honeycomb Structures Plated with Silver and Infused with Fe3O4–Epoxy Composite for Microwave Absorption Applications

As the electronic industry continues to progress, there is a parallel increase in demand of materials for advanced electromagnetic interference (EMI) shielding. A hybrid approach is introduced by combining 3D geometrical structure with the integration of radar-absorbing materials (RAMs) to develop absorptive materials. Present study involves the fabrication of polylactic acid-based pyramidal honeycomb structures using 3D printing technology, followed by electroless silver plating and infusion with Fe₃O₄/epoxy composite. These developed structures/materials test comprehensive within frequency range of 8.2–12.4 GHz (X-band) using free space, and waveguide methods, focusing on both electromagnetic properties of RAM and EMI shielding performance of structures. Experimental results showcase exceptional potential of fabricated structures, demonstrating efficient EMI shielding up-to −55 dB, equivalent to 99.999% attenuation of EM waves. Particularly noteworthy is the dominant role of absorption as a primary shielding mechanism, as evidenced by more than 99% (−20 dB) absorption across the entire tested frequency spectrum.