New filament deposition technique for high strength ductile 3D printed parts

Abstract

Amputees across the world are often left with inadequate solutions to their needs due to a lack of financial resources or access to proper infrastructure and expertise. Current methods of lower limb prosthetic socket fitting and fabrication are too expensive, labor intensive, and dependent on highly skilled technicians, and thus are not suitable to properly serve patients in rural, impoverished areas, particularly in developing countries. Additive manufacturing techniques, and in particular Fused Deposition Modeling (FDM), have already been widely utilized to fabricate products designed specifically for an individual customer and therefore, they show promise in use for manufacturing customizable prosthetic sockets. Current additive manufacturing methods are either too expensive for use in developing countries or result in parts that are not fit to bear the load of a patient, and thus, their use in socket manufacturing for developing countries has been limited. The goal of this research is to develop a technique that enables an off-the-shelf FDM printer with minimal modifications to manufacture durable, reliable, and inexpensive prosthetic sockets. This is accomplished through the development of a new deposition technique to increase the strength and ductility of FDM printed parts without changing their geometry or significantly increasing their expense to print. This novel technique has been simulated through a Finite Element Model and subjected to mechanical testing to validate its proposed enhancements to a printed part’s material properties and its feasibility for use in manufacturing prosthetic sockets.