Improvement of Mechanical Properties of Personalized Insole Manufactured with Selective Laser Sintering Based on Process Parameter Optimization and Cell Structure Design

Personalized insoles manufactured with selective laser sintering (SLS) technology are popular especially for exercisers and patients with foot diseases. However, insufficient strength and toughness of personalized insoles would result in crack and even fracture. To address these deficiencies and fill the research shortages in this area, optimization of process parameters and design of cell structures are conducted to improve the mechanical performance of insoles in this topic. First, six sets of process parameters in terms of energy density were designed for parameter optimization. The energy density of 0.08 J/mm2 was affirmed to be the finest selection. Then, specific cell structures featuring both whale shark and ancient soldier armor (WS structures for short) with various curvature radius were established to act on the bottom of the insole to further strengthen the personalized insoles. It was shown that the WS14 structure exhibited the best performance characteristics. Finally, a personalized insole with the array of WS14 structures was developed with SLS under the optimum energy density of 0.08 J/mm2. Finite element method analysis and exercising testing were performed to evaluate the insole performance. The result reveals that a more uniform stress distribution is attained of the WS14 personalized insole, and the fracture problem is indeed solved.