Vh s5

The mixing by gas flow was imaged using microbeads (diameter: 45 μm). To form a lipid bilayer, 4.2 μl of DPhPC (20 mg/ml in n-decane) was added to the wells with no microslits. Then, 25 μl of buffer solution was added to the wells with microslits, and 21 μl of buffer was added to the other wells. The 1.0 M KCl buffer solution was adjusted to pH 7.0 with 10 mM phosphate buffer. The movement of the microbeads caused by gas flow was recorded by a microscope (VH-S5, KEYENCE, Japan). The gas flow rate was monitored by a flow meter. We used PIV to evaluate the mixing in the droplet. Tracers (diameter: 10 μm; Kato Koken, Japan) were dispersed at 0.1% solid concentration. The experimental system is composed of a 16-channel gas flow device, a visualization laser (PIV Laser G2000, Kato Koken, Japan), and a high-speed camera (k8-USB, Kato Koken, Japan). The laser irradiated a laser sheet (thickness: 2 mm) in a direction parallel to the gas flow device. The high-speed camera was placed above the gas flow device to obtain top-view images. We used four N₂ gas flow conditions: 0, 0.1, 0.2, and 0.3 liters/min. The direct cross-correlation method was used for vector calculation using PIV analysis software (Flow Expert 2D2C, Kato Koken, Japan) (30 ). The differences in particle velocities were evaluated quantitatively depending on the particle position and the gas flow rate.