Mid-air tactile display using indirect laser radiation for contour-following stimulation and assessment of its spatial acuity

This paper presents a mid-air tactile display based on indirect laser radiation designed to provide continuous moving tactile sensations along a contour on the skin. The display uses a small laser device with 1064 nm wavelength mounted on a motorized gimbal for the control of laser radiation direction. A laser is irradiated on an elastic medium attached to the user's body, and the medium is made of black rubber-coated polyvinyl chloride (PVC) for laser-induced thermoelastic deformation. LaserStroke generates tactile stimuli sufficient for clear perception, and this is confirmed by measurements. We also report a psychophysical experiment carried out to study the spatial acuity of laser-induced tactile stimuli by measuring point localization thresholds. Results indicate that LaserStroke has adequate performance for transmitting continuously moving tactile sensations through the air.