OneTip: A soft tactile interface for 6-D fingertip pose acquisition in human-computer interaction

Advances in display technology have created the need for more efficient and natural multi-degree-of-freedom interaction devices. The movement of a single fingertip has six degrees of freedom (DOFs), but traditional rigid touchscreens usually sense only 2-D information. This article proposes a new deformable tactile interface, OneTip, for single-fingertip human-computer interaction with 6 DOFs. It is manufactured based on the principle of vision-based tactile sensing using virtual stereoscopic cameras, and its size is about twice that of a thumb. The contact surface of OneTip has a specially designed structure and material to mimic the sensitivity and softness of human skin. Also, OneTip employs a new sensing method to address the problem of soft fingertip pose estimation (measuring relative change only) with incipient slip effects. Experiments show that OneTip has good 6-D pose estimation accuracy, with root mean square errors (RMSE) of translation and rotation not exceeding 0.1 mm and 2.6°, respectively, within the linear interval (x and y: $-$1.2–1.2 mm; z: 0–3 mm; yaw: $-$15–15 deg; pitch and roll: $-$40–40 deg). Experiments were also conducted to explore the application of OneTip in typical virtual manipulation tasks and the possibility of combining it with other interaction devices.