フィルム型光導波路を用いた多点気液相検出法の開発

抄録

Various industrial processes use droplet impingement phenomena, for example, two-phase flow jet in semiconductor cleaning, inkjet method in producing organic EL display, and more. For that, researchers extensively study droplet impingement onto a solid surface. Although a general experimental method is a time-resolved visualization with cameras, long-time and high-speed recording are incompatible. Therefore, we newly developed a droplet detection method with a Film-based Optical Waveguide (OWF). The OWF is a thin and flexible film that has multi-microsensors for gas-liquid phase detection. In this study, we investigated the OWF signals delivered during the measurement of the droplet (d=2.9mm) impact. Time delays for liquid phase detection among the sensors appear, which we can use to estimate radial velocity during the droplet impact with deformation. Moreover, a characteristic peak emerges when the sensor detected a vicinity of the droplet center. These results imply that the OWF can measure the extremely high-speed local surface motion of the impacting droplet.