Application of multi-criteria decision-making methods in the selection of additive manufacturing materials for solid ankle foot orthoses

The present study aims to focus on material selection using FDM for solid ankle foot orthoses, a problem that has not been adequately addressed in previous studies. To address this issue, the present case study employs, for the first time, a combination of recently developed and other Multi-Criteria Decision-Making (MCDM) methods, including Simple Weighted Sum Product Method (WISP), Measurement Alternatives and Ranking According to Compromise Solution (MARCOS) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). This study evaluates seven different materials based on eleven carefully selected criteria, which reflect the essential properties required for SAFOs fabrication using FDM. The criteria weights are determined based on the analytical hierarchy process (AHP). The results of above methods reveal that the most suitable material selected for SAFOs is polylactic acid (PLA) followed by nylon and polycarbonate. Additionally, the study examines the rank reversal problem and find that AHP-MARCOS is stable in performance while AHP-WISP and AHP-TOPSIS suffer rank reversal problems. This research provides valuable guidance for material selection in SAFOs fabrication using FDM and is expected to assist researchers and clinicians who may lack the necessary expertise in selecting appropriate materials for SAFOs and analysing their outcomes.