Lightweight Wearable Fingertip Haptic Device with Tangential Force Feedback based on Finger Nail Stimulation

We introduce a lightweight wearable haptic device providing tangential force feedback through fingernail stimulation. The device uses a ring structure on the fingernail with three miniature motors: two for string-based feedback and one with an arc-shaped pin. The design maintains finger pad sensitivity by placing actuators on the nail side while delivering 2-DOF force feedback. Weighing 5.24g, the device generates nine force patterns by combining string tension and pin pressure. User studies evaluated direction discrimination and perception of weights and friction coefficients.