Design and prototyping of an active hand prosthetic device

Purpose – This paper presents the design and prototyping of the Inherently cOmpliant light Weight Active (IOWA) hand, an active hand prosthetic device. Design/methodology/approach – This hand prosthetic device has five actuated fingers, each with three joints. Each joint is designed using a novel, flexible mechanism based on the loading of a compression spring in both transverse and axial directions, and using cable‐conduit systems. Rotational motion is transformed into tendon‐like behavior, which enables the location of the actuators far from the arm (e.g. on a belt around the waist). Findings – It was shown that several numerical approaches for the study of a mechanical spring undergoing loading conditions in tension, bending moment, and shear can be obtained towards analysis of motion for control of each finder segment. It was also shown that these numerical models are accurate in comparison with experimental results. Originality/value – While the mechanical design of the hand and associated kinematics were presented, we draw an early conclusion (without actual clinical testing) that this type of low‐cost inherently compliant hand may have a significant impact for providing added capabilities to a disabled person. It was also shown from the prototype that adequate control over the mechanical linkages leading to each segment of each digit is possible.