Development of a Low-Resistance Haptic Device for Multi-Segment Force Feedback on the Fingers

Abstract

Haptic devices based on exoskeleton mechanisms, which are capable of providing proprioceptive feedback, have been actively studied; however, their inherent mechanical resistance often constrains natural finger motion and limits usability in interactive tasks. To overcome this issue, we propose a wire-driven haptic device that provides proprioceptive and pressure feedback to multiple finger segments while achieving high mechanical transparency (Fig.1). The device was designed to minimize motion interference and enable localized sensory presentation. We first evaluated the kinematic influence of the device by comparing finger range of motion and motion time with and without the device. A study with eight participants showed that when wearing the device, the range of motion remained at $\text{9 5} \pm \text{3. 6 5 \%}$ of the bare-hand condition, and the time required for rapid reciprocal finger motion was 99.1 ± 11.0% of the bare-hand condition. We then evaluated the perceptual and functional effects of the presented sensations with 10 and 7 participants, respectively. In a force-location discrimination task, participants correctly identified the stimulated finger segment with an accuracy of $85.6 \pm 12.9[\%]$, demonstrating reliable spatial perception. Furthermore, task performance significantly improved when proprioceptive and pressure feedback were provided compared to the no-feedback condition (Wilcoxon signed-rank test, $\mathrm{W}=\text{1. 0, p}=\text{0. 0 4 6}$). These results show that the proposed device simultaneously achieves low mechanical resistance and effective multi-segment sensory feedback, highlighting its potential for dexterous manipulation and immersive human-robot interaction in VR and teleoperation scenarios.