Multi-physical honeycomb metastructure fabricated by fused deposition modeling with broadband radar absorption and mechanical resistance for drones

Complex structural configuration design is necessary for dielectric-magnetic lossy composites to achieved broadband microwave absorption in civil and defense applications. Based on the unique space filling characteristic of fractal structure, the honeycomb metastructure can possess microwave absorption and mechanical resistance. However, traditional molding technique was difficult to realize complex shape of metastructure. Herein, the dielectric-magnetic filament with different concentration of carbonyl iron particles was fabricated by high-temperature extrusion process. The multi-physical honeycomb metastructure with gradient layers was printed by fused deposition modeling (FDM) in a large size. The printed dielectric-magnetic samples exhibited strong dielectric-magnetic loss with high printing quality. The honeycomb metastructure achieved broadband microwave absorption in the −10 dB bandwidth of 9.6–18 GHz with tensile strength of 31 MPa. The results indicate that FDM is useful to fabricate metastructure with complex shape for broadband microwave absorption. The dielectric-magnetic properties of filament are magnified by metastructure design. The proposed design-fabrication process is promising for functional structure realization with complex shape in the future. Highlights: 1. Magnetic filament was fabricated for functional 3D printing. 2. Structural magnetic dissipation mechanism for microwave was presented. 3. Magnetic metastructure was designed and printed for broadband absorption. 4. Integrated design of mechanical and electromagnetic function was presented. 5. Structural absorption effect of honeycomb metastructure was revealed.