Design and optimization of bamboo-laminate prosthetic feet: A sustainable,cost-effective alternative to carbon fiber models

Abstract

Commercially available prosthetic feet are expensive due to the use of advanced composite materials, typically consisting of a thermosetting polymer matrix reinforced with continuous carbon fibers, and the highly labor-intensive manufacturing processes required for their production. Furthermore, carbon fiber laminates present significant environmental challenges due to their energy-intensive fabrication and limited recyclability.

This work proposes an innovative design methodology for custom prosthetic feet utilizing bamboo laminate, a sustainable, cost-effective, and widely accessible material. The work begins with a comprehensive analysis of existing prosthetic solutions, including an evaluation of commercial prosthetic models and their compliance with established biomechanical and engineering standards. Then the drawn design principles of prosthetics feet are systematically applied, encompassing material selection and the optimization of geometric parameters to closely replicate the mechanical behavior and user comfort of conventional prosthetic feet. The roll-over shapes of the feet are utilized as reference metric to evaluate the feet design.

Then a specific commercial prosthetic foot is reverse-engineered and experimentally tested. The data and the drawn design method are used for the design, the development, the validation, and the refinement of the bamboo laminate prosthetic feet. Moreover, design constraints related to aesthetics and functionality are considered. The designed bamboo laminate prosthetic foot achieves a strength-to-weight ratio comparable to that of carbon fiber laminates, with a stiffness variation of less than 10% and a marginal increase in height of only 1.35%.

Therefore, the feasibility of bamboo laminate prosthetic foot is confirmed. The proposed design is an high-performance, cost-efficient, and environmentally sustainable alternative to the commercial prosthetic foot for a broader population of users.