Fusing Topology Optimization and Pseudo-Rigid-Body Method for the Development of a Finger Exoskeleton

Robotic hand exoskeletons can assist people who suffer from hand.functional disabilities caused by a stroke. However, currently existing hand exoskeletons remain inadequate in terms of user-friendly design, lightweight structure, and accurate modeling of hand motion. In this study, a large displacement compliant mechanism is developed as a finger exoskeleton. First, a topology configuration is developed which contains information on hand biomechanics and thus yields an efficient force-deflection mechanism for a finger. A pseudo-rigid-body model is then established using a large-deformation flexible hinge to solve the point flexure problem to create a finger exoskeleton that functions as intended. Finally, the mechanism synthesis method is used for parameter optimization to ensure that the output port of the device matches the motion of the finger. Using the proposed method, an integrated compliant finger exoskeleton is developed, and the performance of the exoskeleton is evaluated. The experimental result shows that the finger exoskeleton prototype provides suitable movement guidance for the index finger, which demonstrates that the proposed method may be a good way in the design of hand exoskeletons.