Design, Simulation, and Fabrication of Composite Lattice Orthoses With Enhanced Structural Performance

Orthoses play a critical role in rehabilitation by providing fracture stabilization, external load protection, and deformity correction. Traditional methods of orthotic manufacturing often result in increased bulkiness and weight due to material and processing limitations, and reduced breathability leading to potential skin problems. This study aims to enhance structural performance of orthoses through the utilization of a fiber-reinforced composite lattice design fabricated using a coreless filament winding process. An arm brace was designed and manufactured, which incorporates four modules made of fiberglass/polystyrene composite lattices assembled together using adjustable thermoplastic connectors. To simulate the structural performance, a finite element model (FEM) was constructed with careful consideration of the interactions between the connectors and the lattice modules, and this was subsequently validated through experiment. In comparison to a benchmark brace made of polylactic acid lattice, the composite brace exhibits a significant reduction in thickness (59$%$⁠) and weight (38$%$⁠) while maintaining similar structural performance. The validation test indicates the FEM’s reliability in predicting structural stiffness and strength of the composite brace, with the predicted load-bearing capacity being slightly conservative (5$%$⁠) compared to experimental results. Composite lattice structures represent a significant advancement in the design of lightweight, high strength, and breathable orthoses. Moreover, the developed FEM serves as a valuable tool for accurately predicting structural performance and optimizing orthotic design under varying loading conditions.