Effects of Infill Density on 3D Printed Socket for Transtibial Prosthetic Leg

Diabetic foot syndrome (DFS) has become the major cause of lower limb amputations in Malaysia. The amputees in Malaysia facing difficulties in receiving suitable prostheses due to higher cost of fabrication including material supply and time consuming. Currently, the minimum duration to fabricate a socket is about two weeks, and thus may still at risk for unfit during the fitting session. The socket has to be modified to suit the patients or to replace to accommodate the changes of the residual limb over time. As an alternative to the problem, this innovation project is conducted to promote the 3D printing approach in developing the lower limb socket. The objectives of this project are to (i) design a lower limb socket for below knee amputees according to size and shape of residual stump, (ii) analyze the performance of the socket at different infill density and (iii) fabricate the lower limb socket using 3D Printing technology. The material used in this project is Polylactic Acid (PLA) with thickness of 15mm. Different set of infill density was considered in this study which are 20%, 40%, 60%, 80% and 100%. A pressure loading presenting 600N load was exerted inside the socket and fixed as the bottom of the socket. Resulting von Mises stress, total deformation and shear stress were the parameter being measured to predict the socket performance. The best and optimum parameter was chosen and printed which is the 60% of infill density.