A novel prosthetic finger design with high load-carrying capacity

Abstract

Hand loss can cause a significant reduction in functionality and psychological damage, which can be partially recovered by hand prostheses. For 3D-printed prosthetic digits, internal joint forces are critical due to the low strength of 3D-printed components. This paper focuses on the analysis and verification of a novel five-link epicyclic (FLE) finger for 3D-printed hand prostheses. The motion and joint forces of the FLE design were analyzed and compared with the commonly-adopted coupled-four-bar linkage (CFBL) design. The results show that the FLE design yields a reduction in internal joint forces between 21.32% and 86.52%, and mimics the proportions and anthropomorphic motion of a human digit. A destructive test was conducted, which experimentally demonstrated the increased load-carrying capacity of the FLE finger. Therefore, the functionality of a hand prosthesis carrying a FLE finger is expected to be improved over that with a CFBL finger, and thus benefit patients suffering hand loss.