Larger Skin-Surface Contact Through a Fingertip Wearable Improves Roughness Perception

With the aim of creating wearable haptic interfaces that allow the performance of everyday tasks, we explore how differently designed fingertip wearables change the sensory threshold for tactile roughness perception. Study participants performed the same two-alternative forced-choice roughness task with a bare finger and wearing three flexible fingertip covers: two with a square opening (64 and 36 mm(2), respectively) and the third with no opening. The results showed that adding the large opening improved the 75% JND by a factor of 2 times compared to the fully covered finger: the higher the skin-surface contact area, the better the roughness perception. Overall, the results show that even partial skin-surface contact through a fingertip wearable improves roughness perception, which opens design opportunities for haptic wearables that preserve natural touch.