Mid-air tactile stimulation using laser-induced thermoelastic effects: The first study for indirect radiation

Abstract

This paper reports our recent finding that a laser that is radiated on a thin light-absorbing elastic medium attached on the skin can elicit a tactile sensation of mechanical tap. Laser radiation to the elastic medium creates inner elastic waves on the basis of thermoelastic effects, which subsequently move the medium and stimulate the skin. We characterize the associated stimulus by measuring its physical properties. In addition, the perceptual identity of the stimulus is confirmed by comparing it to mechanical and electrical stimuli by means of perceptual spaces. All evidence claims that indirect laser radiation conveys a sensation of short mechanical tap with little individual difference. To the best of our knowledge, this is the first study that discovers the possibility of using indirect laser radiation for mid-air tactile rendering.

Sparkle

“…Recently, laser light has been used to create tap-like [19] and impulse sensations at the fingertip [27]. The indirect laser-light stimulation utilizes the thermoelastic deformation of a laser-light absorbing medium attached to the skin (e.g., acrylic tape) to create mechanical waves that stimulate the mechanoreceptors [19].…”

“…The indirect laser-light stimulation utilizes the thermoelastic deformation of a laser-light absorbing medium attached to the skin (e.g., acrylic tape) to create mechanical waves that stimulate the mechanoreceptors [19]. The direct laser-light stimulation creates a diminutive, touchable aerial image, but the laser necessitates an intensity that is strong enough to create a visible image and weak enough to avoid damaging the skin [27].…”

“…Unlike previous solutions to facilitate the input and to give haptic feedback for hover gestures, SPARKLE does not attach an actuator to the finger (e.g., a laser-light absorbing medium [19], a piezo [30], or a magnet [39]), which is undesirable to wear for casual in-air interactions. Unlike focused airborne ultrasound [6,25], SPARKLE enables a shorter working distance and creates sharper sensations suitable for hover interactions.…”

Towards disappearing user interfaces for ubiquitous computing: human enhancement from sixth sense to super senses

“…Spatial accuracy is further enhanced but the power consumption is relatively higher (Iwamoto et al 2008;Inoue et al 2015). Laser-induced thermoelastic effect also produces free air haptics but the precise control of laser pulse timing and energy is the most critical factor in safely utilising the technology (Jun et al 2015;Hojin et al 2015).…”