Bone-inspired lattice structures for biomedical applications: Design, pore network analysis, and mechanical performance

This study aims to design metamaterials that replicate trabecular bone anisotropic structure and mechanical performance for bone replacement applications. While triply periodic minimal surface (TPMS) gyroid structures like sheet (SHN) and solid (SON) networks have been explored for bone replacement, their uniform designs fail to fully capture bone's anisotropy. To address this, we propose a hybrid (HYB) strategy as a more effective solution. We investigate bone-inspired structures by comparing human proximal femur models from micro-computed tomography (CT) images. A 3D lattice was extracted from the trabecular bone region, and compared with TPMS gyroid structures: SHN, SON, and HYB. All structures were standardized to a ∼33.75 % relative density, ensuring a fair comparison, and their anisotropic behavior was analyzed using micromechanical homogenization. Finite element (FE) simulations under various loading conditions confirmed their elastic response and anisotropy. Additionally, the anisotropic behavior of bone material was also analyzed using bone analysis, while pore network modeling (PNM) characterized key pore parameters. Experimental validation included 3D printing via fused deposition modeling with carbon fiber-reinforced polylactic acid, followed by compression testing and elastoplastic FE simulations. Our results show that, compared with uniform TPMS structures, the HYB design closely replicates bone, making it a strong candidate for bone replacement applications.