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Description
The development of next-generation upper-limb prostheses requires a patient-centered approach that prioritizes comfort, functionality, and anatomical integration. Traditional fabrication methods involve multiple manual steps and require the physical presence of the amputee. In contrast, advances in 3D printing now enable the production of lattice structures that provide an excellent balance of mechanical performance, combining stiffness, strength, and low weight. This study presents the design, numerical simulation, and additive manufacturing of an ultralight forearm socket based on lattice structures. Firstly, 3D scans of the residual limb, contralateral limb, and plaster model were acquired. Using the plaster scan, the liner was generated via offset and trimming along anatomical reference points. Two iterations corrected global alignment, and two further refined the anterior geometry. The outer socket was designed to restore anatomical proportions and accommodate myoelectric prosthetic components. A planar lattice structure was adopted for the socket, and polyamide 12 (PA12) was selected for manufacturing due to its mechanical properties, biocompatibility, and cost. Elastic-plastic homogenization was implemented to study the orthotropic behavior of lattice cells by varying strut diameters. Two test specimens with different lattice orientations were manufactured using multi-jet fusion (MJF) to validate the homogenized properties. Finally, finite element-based stress-informed optimization was used for the socket by adjusting strut diameters according to local stress, reinforcing high-stress areas and lightening low-stress zones. Comparison of stress–strain curves from homogenized, full-scale simulations and experiments showed excellent agreement. The optimized lattice reduced weight by 25.4% and 13.2% relative to solid and average-diameter lattice sockets, respectively with a minimum safety factor of 4.2. CT scans confirmed that the manufactured socket matched the CAD design. This methodology demonstrates a fully integrated workflow combining stress mapping, homogenization, and additive manufacturing to produce lightweight, anatomically compatible, and mechanically reliable prosthetic sockets, laying the foundation for future clinical investigations.