Design and Fabrication of a Customized and Fully-Recyclable Carbon Fibers/Epoxy Composites Prostheses via a Functional Additive Manufacturing Approach

This study presents an innovative approach based on the combination of two different techniques for fiber-reinforced epoxy composites manufacturing, i.e., additive manufacturing (AM) and hand lay-up-assisted vacuum bagging. It represents a proof of concepts for the manufacturing of a customized and lightweight lower-limb prostheses having built-in functional elements, such as sensors. In particular, a soluble tool for fabricating a complex-shaped carbon reinforced epoxy composite is produced by AM. The 3D printed model is properly designed to integrate a functional element, in a customized way, within the composite structure itself. Moreover, a fully-recyclable epoxy resin system is used as matrix for the fabricated composite part to recover the expensive functional part and carbon fibers as soon as the prostheses has reached the end of its life (EoL). The prostheses recycle is carried out through a chemical recycling process that relies on the presence of acid-cleavable groups within the epoxy-cured network that allows for the cleavage of the crosslink under certain conditions. A similar approach is proposed in the state of art, but by using the traditional autoclave prepreg process and without considering the handling of the part at its EoL.