Multifunctional meta-absorber based on CB-PLA composite and magnetic materials for electromagnetic absorption and load-bearing capacity

Low-profile electromagnetic (EM) absorbers with broadband absorption properties meet the stealth requirements of low-observable platforms. However, most studies of these EM absorbers rarely focus on mechanical properties. Based on carbon black (CB)-polylatic acid (PLA) composite and magnetic materials, this study offers a novel design recipe for meta-absorbers with excellent EM performance and mechanical properties. The three dimensional (3-D) printed lossy dielectric structure, with a thickness of 20.1 ± 0.1 mm and fabricated from the CB-PLA composite, and the 1.3 mm thick magnetic substrate are utilized as the principal frequency-dependent functional motifs. To validate the design, the optimized meta-absorber was manufactured, and the experimental findings demonstrate that its reflection coefficient remains below −10 dB within the frequency range of 1.36–40 GHz. The lossy dielectric structure exhibits a compressive strength of up to 3.75 MPa while maintaining a density of just 178.2 kg/m³, with an energy absorption capacity of 1.49 × 10³ kJ/m³ per unit volume. The overall thickness of the meta-absorber is 21.4 mm, equivalent to approximately 0.097 times the wavelength at 1.36 GHz. The proposal paves the way for the new paradigm of multifunctional meta-absorbers for both EM absorption and load bearing.