StringTouch: A Non-occlusive 3DoF Haptic Interface Using String Structures for Modulating Finger Sensations

Providing realistic and diverse tactile feedback during interactions with objects in virtual and augmented reality, various studies have explored the use of tangible proxies. However, tangible proxies face limitations due to their fixed physical properties, restricting the expression of various stiffness, weights, and shapes. To address these issues, we propose StringTouch, a device modulating sensations from proxies without obstructing the fingers to preserve finger sensitivity. StringTouch modulates sensations utilizing 0.2mm thin nylon threads tactor to deform fingers with 3DoF. In a user study (n = 12), our string structure showed better performance in distinguishing orientation, roughness, and weight than conditions using a 0.1 mm latex finger cot and was comparable to bare fingers in some of the discriminating tasks. Another experiment (n = 12) verified the device’s capability to modulate orientation, stiffness, and weight perceptions. Finally, in a user study (n = 10) in proxy-based VR scenarios (pouring water, touching a teddy bear, touching a bottle), participants preferred StringTouch over bare finger interactions, with most of them reporting enhanced presence.