Hydroptical Thermal Feedback (UIST ’24)

Switching water temperature perception using visible lights. (日本語)

Sosuke Ichihashi, Masahiko Inami, Hsin-Ni Ho, and Noura Howell. 2024. Hydroptical Thermal Feedback: Spatial Thermal Feedback Using Visible Lights and Water. In Proceedings of the 37th Annual ACM Symposium on User Interface Software and Technology (UIST ’24). Association for Computing Machinery, New York, NY, USA, Article 104, 1–19. https://doi.org/10.1145/3654777.3676453

About

How can we switch water temperature instantly? In our UIST ’24 paper, we propose a way to alter how you perceive water temperature using light.

Our hydroptical method creates warm water perception by shining light on the skin under cold water. The perceived water switches back to the original cold water when the light is turned off.

Applications

Interactive Water Temperature

Hydroptical method turns water temperature into an interactive material for gaming, VR, therapies, energy saving, movies, and more. In this VR example, the user teleports from a cold ocean to a hot spring, experiencing not only the audiovisual change but also the water temperature change.

Personalizing Shared Water

Hydroptical method can spatially diverge water temperature even in a single water body. In this example, the user on the left is enjoying a cold foot bath while the user on the right is enjoying a warm foot bath.

Psychophysical Studies

We conducted four psychophysical studies to explore the perceptual characteristics of hydroptical thermal feedback. Please refer to the paper or the video for more detail. Here, we briefly summarize the results.

Study 1: Validation of the effect & comparison of light colors

It works; cooler colors are warmer. The graph colors represent the corresponding light color conditions. The subjective rating results were consistent with this physical measurements.

Study 2: Adjustability & reaction time

The brighter the light is, the warmer it gets; the user reacts to the light in 1.5 sec.

Study 3: Movability (apparent motion)

The warm point can be smoothly moved along the skin by successively turning on and turning off multiple lights.

Study 4: Illusory water temperature perception

In contrast to Study 1-3, where lights are shone only on the palm, we shone the entire skin under water to create illusory water temperature perceptions. We observed 13 ℃ rise in water temperature perception in 25 ℃ water.

Publication

Sosuke Ichihashi, Masahiko Inami, Hsin-Ni Ho, and Noura Howell. 2024. Hydroptical Thermal Feedback: Spatial Thermal Feedback Using Visible Lights and Water. In Proceedings of the 37th Annual ACM Symposium on User Interface Software and Technology (UIST ’24). Association for Computing Machinery, New York, NY, USA, Article 104, 1–19. https://doi.org/10.1145/3654777.3676453

Contribution

• Sosuke Ichihashi (Georgia Tech)
• Masahiko Inami (University of Tokyo)
• Hsin-Ni Ho (Kyushu University)
• Noura Howell (Georgia Tech)