Water condensation (Ketsuro in Japanese) is a natural canvas found on a car window or a glass on which we often scribble figures, illustrations, and messages. In this paper, we propose Ketsuro-Graffiti, a novel canvas that shows images with computer generated water condensation and enables users to touch them freely. Users can write or apply graffiti with their fingers on a pattern of water generated condensation. The proposed system basically consists of peltier devices, an array of heat conductive actuators, and a display surface. The peltier devices keep the actuators cold. When an actuator moves up and touches the rear side of the surface, the temperature of touched area falls below the dew point and a pixel of condensation grows there. We conducted a preliminary experiment to examine whether the dew points of the surface accord with the saturated water vapor pressure curve. From the results, the dew points from Ketsuro-Graffiti are confirmed to accord with the saturated water vapor pressure curve. Therefore, we can apply the saturated water vapor pressure curve to estimate the conditions under which water condensation is generated and conclude that we can control the appearance and the disappearance of water condensation using theoretical values. Ambient display is a potentially attractive application. Our proposed display can show patterns, images, and characters by controlling the presence or absence of water condensation. For example, if a mirror with our proposed display is installed in a house's entryway or a washstand, it can present such modest information as weather forecasts or changes in body weight with a pattern of water condensation. Thus, our proposed display might function as a subtle information display.

Presenter(s)

Yuki Tsujimoto, Graduate School Of Information Science And Technology, Osaka University
Yuichi Itoh, Graduate School Of Information Science And Technology, Osaka University
Takao Onoye, Graduate School Of Information Science And Technology, Osaka University