Modeling and Prototyping of a Soft Prosthetic Hand Exploiting Joint Compliance and Modularity

摘要

Losing an hand seizes nearly all principal activities of amputees life. However, with the development in the field of prosthesis, amputees can get back to normal life with use of simple yet functional prosthetic devices. In this study, we presents the design, model and 3D printed prototype of a tendon driven underactuated modular soft prosthetic hand. The proposed robotic hand is actuated using only one motor and a differential mechanism. The flexible fingers of the hand are built with stiff link connected with soft joints. Different stiffness of the soft joints can be set to follow the desired bending trajectory of the fingers. A mathematical representation to calculate the desired stiffness needed to follow the predefined trajectory of the finger is detailed. We also present a method to realize the computed stiffness through FDM 3D printer. The presented methodology is used to characterize the soft joints deformation and to realize prototype of the prosthetic hand. Finally, we presented electromyography (EMG) based control interface of hand prosthesis and experiments with activity daily objects consisting of grasping objects of various shapes, sizes and textures. The results showed the good grasping performance of the hand and its ability to adapt different shapes.