Design and Optimization of a Multi-DOF Hand Exoskeleton for Haptic Applications

This paper describes the design and kinematic optimization of a novel, underactuated, linkage driven exoskeleton mechanism to provide haptic force feedback to the index and thumb fingers. Existing exoskeletons are either not compatible with the human hand kinematic chain or so heavy that they cannot be compatibly installed on a human hand, which in turn affects the natural motion of the hand. In order to improve functionalities, the design of a novel (HEXON 11 Hand Exoskeleton of New technologies research center) based on a multi-criteria optimization is proposed to simultaneously maximize applied force to the finger and workspace of the attached exoskeleton. The optimization procedure consists of both the Perpendicular Impact Force (PIF) and the Global Isotropy Index (GIl), considering worst-case collision avoidance. Finally, the exoskeleton mechanism functionalities within the achieved link length through the optimization procedure are validated, and design is proposed for further fabrication.