## 4 Conclusions  
The finite element analysis (FEA) conducted on the Type 3 partial hand prosthesis revealed significant results, confirming the feasibility of the current design. The maximum recorded stresses reached 33.456 MPa, with the highest stress concentrations observed at the finger joints, particularly in areas of contact with objects. These regions indicate the areas most susceptible to failure or deformation under continuous load. Although the prosthesis structure is adequate to withstand typical gripping loads, it is recommended to reinforce the joints to enhance the device's durability. The displacement analysis of the prosthesis model showed a maximum deformation of 1.68 mm at the fingertips, indicating that the prosthesis undergoes deformation under the applied load conditions, especially in areas farthest from the fixation. This expected displacement emphasizes the importance of understanding the impacts of mechanical properties, such as maximum stress, yield strength, modulus of elasticity, and elongation, when selecting the polymer material for FDM printing. These properties are directly linked to the chemical composition and microstructural characteristics of the material, which are essential for ensuring good mechanical strength after three-dimensional printing. Regarding the mechanical feasibility study, static load simulations performed with finite element software indicated that the prosthetic device is mechanically feasible for compressing solid objects under a 50 N force without experiencing plastic deformations or ruptures. The prosthesis model, developed with 25% infill and Tri-hexagonal internal fill geometry, showed good dimensional accuracy and surface finish, resulting in a device with low weight (240 g) and high mechanical strength. The cost analysis revealed that the polymer filament is the most expensive component, priced at BRL 230.00 (USD 38.50) per kg. However, the prosthesis construction achieves an excellent cost-benefit ratio, totaling approximately BRL 300.00 (USD 50.15) per unit. Thus, it is possible to print and build a mechanical hand prosthesis with low production costs using additive manufacturing. It is important to emphasize that this work focused on the development of the prosthetic device based on engineering principles, covering material selection, structural analysis, and mechanical system implementation. Clinical validation, involving human trials and real-world performance evaluations, will be a subsequent phase to be carried out in future stages of the project. Therefore, no clinical trials with the prosthesis have been conducted thus far, and clinical assessment should be carried out in future studies. The prosthesis functions through a muscular propulsion system, where the movements of finger flexion and extension are controlled by forces generated by the remaining muscles of the amputee. High-density cords, fixed along the palmar surface and phalanges, activate finger flexion by being tensioned through wrist flexion. The directional coupling in the system also facilitates precise angulation of the prosthesis, enabling coordinated movement between the wrist and fingers. In conclusion, the evidence obtained through the analyses and simulations confirms that the developed hand prosthesis not only meets functional requirements but also presents a viable solution in terms of cost and performance. The project has the potential to be improved in subsequent phases, with design enhancements and clinical validation, significantly benefiting users by combining quality, comfort, and durability. Conceptualization, R.C.d.S.R. and C.B.S.V. ; methodology, R.C.d.S.R., K.A.C., P.H.R.G.R. and C.B.S.V. ; software, R.C.d.S.R., K.A.C. and P.H.R.G.R. ; validation, R.C.d.S.R., C.B.S.V. ; formal analysis, R.C.d.S.R. ; investigation, R.C.d.S.R. ; resources, R.C.d.S.R. and C.B.S.V. ; data curation, R.C.d.S.R. ; writing--original draft preparation, R.C.d.S.R. ; writing--review and editing, R.C.d.S.R. ; visualization, R.C.d.S.R., K.A.C. and P.H.R.G.R. ; supervision, R.C.d.S.R. and C.B.S.V.