Non-contact Cold Thermal Display by Controlling Low-temperature Air Flow Generated with Vortex Tube

Abstract

In recent years, thermal display has been studied intensively in order to represent a more realistic tactile quality of the object. Since human feels the temperature of the air without touching other objects, it is necessary to present thermal sensation in a non-contact manner. Studies on non-contact heat display have been explored; however, few studies have reported on a device that can display cold in a non-contact manner. In this study, we propose a non-contact cold thermal display using a low-temperature heat source-vortex tube, which can generate ultra-low air temperature when supplied with compressed air. We developed a cooling model that relates the flow velocity of cold air with the absorbed heat from skin; we implemented a prototype system that can control the flow velocity of the generated air; and we conducted an experiment to examine the cold sensation that the system can present. Our results revealed that various cold sensations can be generated so that the faster the flow velocity, the colder a user would feel.

Douleur

“…Blaga et al [6] analyzed the effect of thermal visual cues on users' grasping actions without inducing actual thermal stimulus. Xu et al [96] reported a non-contact cold thermal display using a vortex tube to generate ultra-low air temperature.…”

High-Speed Non-Contact Thermal Display Using Infrared Rays and Shutter Mechanism

“…Han et al combined infrared lamp, mist, water drop and air conditioning [7]. Other non-contact-type methods are air transportations [20,22,31], humidity adjustment [9], vaporization [21],visuo-thermal interaction [18,19,27], and olfactory [2]. These non-contact-type methods do not require contacts to the devices that can result in reductions in the senses of immersion and presence.…”

Mid-air Thermal Display via High-intensity Ultrasound

“…For heating sensation, methods based on infrared lasers [Meyer et al 1976], thermal ladiation [Saga 2015], and high-intensity airborne ultrasound [Kamigaki et al 2020] have been proposed, which can display the heat sensations at a localized area remotely. For cooling sensation, methods based on atomized micro liquid mist [Arai et al 2012], low-temperature air-flow [Xu et al 2019] have been proposed, which can provide cooling sensation at localized areas; however, these methods require close-range (e.g., 5mm) from displays. For displaying the cooling sensation remotely, a method transporting cold air via straight narrow air-flow generated by the ultrasonic Bessel beam has been proposed [Nakajima et al 2018].…”