Laser HaPouch: Modeling and Implementation of Laser-driven Liquid-to-gas Phase Change Actuator Arrays for Haptic Displays

Liquid-to-gas phase change actuators are pneumatic actuators that utilize liquid-to-gas phase transitions for actuation and have attracted attention as high-output, wirelessly driven actuators whose actuation is directly induced by heating. In this study, we propose a shape-changing haptic display that can be fabricated through computer-controlled processes, utilizing actuator arrays of liquid-to-gas phase change actuators arranged on a two-dimensional plane. The developed automated fabrication system enables high-precision fabrication of actuator arrays with diverse geometric patterns, such as grid and honeycomb types, from design patterns. Furthermore, we constructed a system capable of independent control of each pouch-type actuator through selective wireless driving using CO2lasers and galvanometer scanners. This allows users to safely perceive shape deformation through direct touch. We also constructed a theoretical model of polygonal actuators and established a method for calculating the minimum liquid volume for arbitrary shapes. Through pressure distribution measurement experiments, we demonstrated that the system can generate approximately 7.4 N of force per actuator and achieve selective driving without affecting neighboring actuators. This research provides a new approach to shape-changing haptic displays that require fewer components and offer excellent scalability.