Nonmotorized Hand Exoskeleton for Rescue and Beyond: Substantially Elevating Grip Endurance and Strength

Abstract

Robotic hand exoskeletons hold immense potential for enhancing human hand functionality, addressing the hand's strength limitations and fatigue during physically-demanding tasks. However, most existing hand exoskeletons are motorized, being weak in generating high supporting force for gripping augmentation. We present a non-motorized hand exoskeleton based on magnetorheological (MR) actuators to provide high gripping support and elevate grip endurance. Meanwhile, it ingeniously harnesses human energy for actuation and energy storage, enhancing grip strength without external power. The MR actuator demonstrates a peak holding force of 1046 N with merely 5 W power input, boasting a force-to-power ratio one-order-of-magnitude higher than conventional approaches, and 97.7% energy reduction for same holding force compared to other approaches. Participants wearing the hand exoskeletons experience a 41.8% enhancement in grip strength without external power and reduced hand muscle fatigue during prolonged physical labor. In rescuing scenarios such as post-earthquake rescue, debris clearance, and casualty evacuation, our exoskeleton effectively supports gripping and improves working efficiency.