A Novel Adaptive Prosthetic Finger Design with Scalability

Abstract

The complex mechanical structure of multiple-link prosthetic fingers makes their application on low-cost 3D-printed prostheses quite challenging. Even worse, the limited scalability of the existing solutions has become a significant burden for creating child-size prostheses for eight-year-olds or younger. In this paper, we introduce a novel compliant five-link epicyclic (CFLE) finger for 3D-printed hand prostheses. Its unique joint distribution along the kinematic chain renders it an excellent candidate for 3D printing. Moreover, the design allows for a prosthetic finger to be 3D-printed at 50% of the adult size, suitable for four-year-olds or younger. The CFLE finger is modeled as a kinetostatic system based on constraint analysis and pseudo-rigid body (PRB-3R) modeling. Experiments were conducted with an adult-size finger prototype to verify the kinetostatic model and demonstrate its grasping adaptability.