Biomimetic Design and Extrusion-Based 3D Printing of TiO2 Filled Composite Sphere Scaffolds: Energy-Absorbing and Electromagnetic Properties

The development of composite materials with tunable dielectric properties that preserve mechanical performance is essential for next-generation radio engineering devices. In this study, composite filaments based on acrylonitrile-butadiene-styrene (ABS) with 0-40 wt.% TiO₂ solid loading were developed for 3D printing. The dielectric permittivity and mechanical properties of the 3D-printed parts strongly depend on the TiO₂ content. Using these filaments, we fabricated biomimetic lattices based on triply periodic minimal surfaces (TPMSs) using fused filament fabrication (FFF). The intrinsic porosity of the TPMS lattices further enables tuning of dielectric permittivity, facilitating their integration into gradient-index components. This multifunctionality was demonstrated by fabricating a spherical Luneburg lens prototype, which exhibited stable antenna performance in the 8.0-12.5 GHz frequency range. The results confirm that TPMS lattices based on the ABS-TiO₂ composite can simultaneously deliver mechanical robustness and dielectric tunability, opening new pathways toward multifunctional components for advanced radio engineering systems and beyond.