Lightweight custom composite prosthetic components using an additive manufacturing-based molding technique

Abstract

Additive manufacturing techniques are becoming more prominent and cost-effective as 3D printing becomes higher quality and more inexpensive. The idea of 3D printed prosthetics components promises affordable, customizable devices, but these systems currently have major shortcomings in durability and function. In this paper, we propose a fabrication method for custom composite prostheses utilizing additive manufacturing, allowing for customizability, as well the durability of professional prosthetics. The manufacturing process is completed using 3D printed molds in a multi-stage molding system, which creates a custom finger or palm with a lightweight epoxy foam core, a durable composite outer shell, and soft urethane gripping surfaces. The composite material was compared to 3D printed and aluminum materials using a three-point bending test to compare stiffness, as well as gravimetric measurements to compare weight. The composite finger demonstrates the largest stiffness with the lowest weight compared to other tested fingers, as well as having customizability and lower cost, proving to potentially be a substantial benefit to the development of upper-limb prostheses.

Additive manufacturing of custom orthoses and prostheses—A review

“…The study showed the feasibility of its use by children in developing countries. Leddy et al [57] used additive manufactured molds to fabricate components for prosthetic hands with multiple and composite materials to achieve light weight and high stiffness. an AM system [11,43], uneconomic throughput and material cost [12,15], and limited material strength [41,46].…”

Multi-input multi-output fractional-order control of an underactuated continuum mechanism

“…Continuum mechanisms provide a passive compliance as the continuum structure reacts to any kind of disturbance with a deformation. The mechanism can therefore collide with the environment without being damaged, which is termed “mechanical robustness.” Mechanisms of this kind are used as finger joints in robotic 1 or prosthetic 2 hands, quadrupedal spines, 3 humanoid necks or spines, 4 or whole robotic arms made of serially attached mechanisms. 5 Furthermore, parallel continuum robots possess a similar design, with multiple continua in between two rigid platforms.…”

The Need to Fabricate Lower Limb Prosthetic Devices by Additive Manufacturing

“…The hope was to influence future prosthetic designs, to create lightweight hand prosthetics that are durable, customizable, and cost-effective. Finally, by using carbon fiber, they were able to build prosthetic hands that are half as heavy as regularly printed 3D hand, and one-quarter of the weight of a machined aluminum hand with more flexible joints [36].…”