Enhancing microwave absorption of bio-inspired structure through 3D printed concentric infill pattern

Despite numerous reports on microwave absorbing materials and structures with excellent performance, research on the impact of the carrier of microwave absorbers and their preparation processes on microwave absorption performance still faces challenges. To address this issue, this study combines theoretical analysis, simulation, and experimental validation to compare the differences in microwave absorption performance between 3D printed ABS/CF/MWCNTs materials and traditionally cast paraffin/CF/MWCNTs materials. Furthermore, the study explores the impact of linear and concentric filling patterns in 3D printing processes on the performance of tree-shaped microwave absorbing meta-structures. From a material level perspective, the 3D printed ABS/CF/MWCNTs composite plate with a thickness of 3 mm has an effective absorption bandwidth of 5.16 GHz. Additionally, the bio-inspired tree-shaped structure optimized by the ant colony algorithm achieves an effective absorption bandwidth of up to 11.5 GHz at a thickness of 10.8 mm, with a minimum reflection loss of less than −9 dB across the entire frequency range (2–18 GHz). Moreover, the microwave absorbing meta-structure reinforced with carbon fiber-reinforced plastic laminates exhibits outstanding tensile and bending strength, with an average tensile strength and bending strength reaching 197.7 MPa and 188.6 MPa, respectively. In summary, this study provides valuable insights into the optimization of preparation processes for microwave absorbing materials or structures and offers a scientific basis for the design and application of high-performance microwave absorbing materials.