Mechanical analysis and sensitivity evaluation of PLA scaffolds for bone tissue repair using FEA and Taguchi experimental design

Abstract

Purpose: The design of three-dimensional scaffolds for bone regeneration poses challenges in balancing mechanical strength, porosity and degradability. This study aimed to optimize the geometric parameters of polylactic acid (PLA) scaffolds fabricated via 3D printing, focusing on pore size, porosity, and geometric configurations to enhance mechanical performance and biological functionality. Methods: Two geometric configurations - orthogonal and offset orthogonal - were evaluated with pore sizes ranging from 400-1000 µm and porosities between 55-70%. Finite element analysis (FEA) in ANSYS Workbench was used to simulate mechanical behavior, while the Taguchi experimental design determined the optimal parameter combinations. Statistical analyses, including ANOVA, assessed the significance of each factor. Results: The study identified a pore size of 400 µm as optimal for structural strength, while a porosity of 70% provided a balance between stability and cell growth. Orthogonal geometries distributed stress more uniformly, reducing critical stress concentrations compared to offset configurations. ANOVA revealed that pore size was the most significant factor, followed by porosity and geometry, achieving a model reliability of R ² = 98.42%. Conclusions: The findings highlight the importance of geometric optimization for improving scaffold mechanical properties while maintaining biological functionality. This study offers a robust framework for designing patient-specific scaffolds tailored to bone tissue engineering applications.

Keywords: 3D printing; Taguchi method; experimental design; finite element method; polylactic acid (PLA); scaffolds; sensitivity analysis.