Hybrid Manufacturing of Upper-Limb Prosthesis Sockets with Improved Material Properties

This paper describes the design and manufacturing process of an advanced socket for upper limb prostheses. This device uses synergies between smart materials such as phase change materials (PCM), reduced graphene oxide (rGO) and a 3D printed metastructure to improve ergonomics and thermal comfort. Virtual prototyping was combined with traditional fabrication techniques to obtain a biocompatible, user-centered device, whose main advantage is an improved thermal behavior. Besides feasibility and biocompatibility tests, the paper describes the results of a preliminary trial involving a volunteer with upper limb amputation. It was observed that the use of an inner metastructure provides basic mechanical stability and improves resin flowability. The combination of PCM and rGO delay the increase in inner socket temperature during physical exercise on a treadmill, which induced a feeling of freshness and dryness and improved the comfort for the user. These findings, despite their preliminary nature, suggest that advanced modifications of the materials and technologies involved in the production of prosthetic sockets are able to generate appreciable benefits in terms of usability.