Optimization of the structure of bionic finger segment prosthesis using generative design

Abstract

Background: Bionic hand prosthesis helps restore the original hand function. A survey on prosthetic users concluded that 79% thought that their devices were "too heavy". Therefore, the weight of the prosthesis is a major cause of user discomfort and fatigue. This research was aimed at the reduction of hand mass bionic prosthesis by optimizing the structure of the fingers with generative design methods. Methods: The materials used were Acrylonitrile butadiene styrene plastic and Nylon 6, and the manufacturing method used Additive Manufacturing. The prosthesis was designed with a lighter finger structure with a max displacement of 2 mm and a maximum safety factor of 4. Results: Generative design produced more than 80 designs. The selection of the best design was based on the status of design solutions, research limitations, visual aesthetics, recommendation values, and validation of mechanical performances. The best is the SS-2. This design has an 80% lighter mass with the highest safety factor of 3.79, the lowest stress of 5.26 MPa, and the maximum displacement of 0.61 mm. Conclusion: Based on the exploration scheme, the generative design could produce more than 80 design solutions. The selection of the best design was based on the status of design solutions, research limitations, visual aesthetics, recommendation values, and validation of mechanical performances in the design. Design validation was carried out by simulating finite element analysis with static stress study methods in selected design candidates with input study cases similar to generative design exploration schemes. Finally, SS – 2 design was the best design produced by the generative design method with the highest factor of safety value of 3.79. Also gives an advantage to a stress value of at least 5.26 MPa in cases of segment loading, as well as the maximum displacement value of 0.61 mm.