Metamaterials for prosthetic sockets

In the fields of prosthetics and orthotics, socket design is still an open challenge. Since the sockets are typically worn the entire day, comfort is a big impact factor. Additionally, the socket needs to provide a very good grip to securely attach the prosthesis to the residual limb. Consider the example of a lower limb prosthesis: as the amputee steps onto the ground during the stance phase, the residual limb receives impact, bears a large portion of the weight, and expands, pushing outwards into the socket. During the swing phase, the load decreases as the wearer lifts their foot off the ground and the residual limb contracts. To compensate for these changes in load and limb, we investigate mechanical metamaterial structures that are tunable to (1) repeatedly damp impact based on the wearer’s activity via novel superelastic cell structures, and (2) maintain a constant pressure on the residual limb for comfortable and secure attachment of the prosthesis using novel constant force spring structures, while (3) keeping the optimized geometry simple and cost-effective to produce for accessibility.

The project could focus on experimentation, modeling, or a combination, depending on student interest and background. Experimentation will involve fabrication using 3D printing and characterization using universal testing machines. Modeling will involve FEM for physics-based modeling, combined with optimization methods for inverse design.