A Skin-Stroke Display on the Eye-Ring Through Head-Mounted Displays.

We present the Skin-Stroke Display, a system mounted on the lens inside the head-mounted display, which exerts subtle yet recognizable tactile feedback on the eye-ring using a motorized air jet. To inform our design of noticeable air-jet haptic feedback, we conducted a user study to identify absolute detection thresholds. Our results show that the tactile sensation had different sensitivity around the eyes, and we determined a standard intensity (8 mbar) to prevent turbulent airflow blowing into the eyes. In the second study, we asked participants to adjust the intensity around the eye for equal sensation based on standard intensity. Next, we investigated the recognition of point and stroke stimuli with or without inducing cognitive load on eight directions on the eye-ring. Our longStroke stimulus can achieve an accuracy of 82.6% without cognitive load and 80.6% with cognitive load simulated by the Stroop test. Finally, we demonstrate example applications using the skin-stroke display as the off-screen indicator, tactile I/O progress display, and tactile display.