One-To-Many Actuation Mechanism for a 3D-Printed Anthropomorphic Hand Prosthesis

Prosthetic hands become more functional and dexterous the more degrees of freedom they can control for grasping objects. Nonetheless, more degrees of freedom implies an increase in the number of actuators, cost and weight, which hinders their usability and accessibility. This paper presents the design of a 3D-printed prosthetic hand powered by a single actuator controlling all fingers through a One-to-Many (underactuated) drive mechanism. In addition, finger trajectory was optimized to transmit the maximum grip force while following a path that resembles human finger kinematics. The implementation and evaluation of a prototype shows that our One-To-Many 3D-printed mechanism enables synchronous opening and closing of all fingers, and allows the performing of cylindrical, spherical and lateral grasps, as well as the lifting of heavy objects.