Comparative analysis of ankle prosthesis connector adapters in 3D printed using PLA and PETG

Abstract

The high price of adapters of lower limb prostheses and the difficulty for the purchase of this product encouraged us to develop a low-cost version using 3D printing. For printing was chosen two types of filaments: polylactic acid (PLA) and polyethylene terephthalate glycol (PETG). This work had as main objective to evaluate, through simulations and mechanical compression tests, the adapter prototypes’ maximum deformations and to identify the best material regarding mechanical resistance. The results obtained through simulations were compared with those obtained from compression tests according to Taguchi orthogonal distribution. A maximum deformation limit of 3 mm was determined, as the average size of the difference in length between the legs of a healthy individual. The maximum deformations found were 0.5976 mm for PETG mate-rial and 0.3103 mm for PLA material. Even tough PLA has shown a lower value of the deformation, PETG was chosen as printing material because no cracks or fractures were found during trials. The results satisfy the imposed maximum deformation limit and are indicators of reliability for use of this component made by 3D printing.