The use of robots in disaster sites has rapidly expanded, with soft robots attracting particular interest due to their flexibility and adaptability. They can navigate through narrow spaces and debris, facilitating efficient and safe operations. However, low visibility in such environments remains a challenge. This study aims to enhance the visibility of soft robots by developing and evaluating a passive luminescent exible actuator activated by a black light. Using Ecoex mixed with phosphorescent powder, we fabricated an actuator and confirmed its fluorescence phosphorescence and deformation ability. Furthermore the effects of the mixing ratio on optical and mechanical properties were assessed.