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

Abstract

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$$^2$$ 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.

Materials and Structural Designs for Neural Interfaces

“…However, since the sensory area of the scalp or the cerebral cortex is rounded rather than flat, it is difficult for the electrodes to conformally contact it. Therefore, one of the most crucial factors for planar electrodes to detect high-quality signals is to cover the uneven surface of neural tissues. , …”

“…Therefore, one of the most crucial factors for planar electrodes to detect high-quality signals is to cover the uneven surface of neural tissues. 74,75 Toda et al collected ECoG signals from the dural/pial surfaces of the visual cortex of rats with an Au electrode array (Figure 4a). 76 The electrode array was formed as a mesh structure, which made mechanically stable contact with the curvature of the cortex.…”

On the perceived realism of virtual textures rendered by a vibrotactile wearable ring display

“…Commercially available haptic displays attempting to close this gap, such as vibrating handheld controllers [1], [2] or gloves [3], [4], generally provide haptic feedback directly to the fingertips or palm. While these locations are where a user would expect sensations during active touch, such placements can be particularly problematic for augmented and mixed reality: occluding the fingertip with gloves or other hardware demonstrably reduces tactile acuity [5], [6], and bulky hardware concentrated in the small workspace of the hand can hamper dexterity. One approach to mitigate these deleterious effects is to "fold away" actuators when not needed, and apply them to the fingertip only during virtual interactions [7].…”