Measurement of interfacial properties among fluids by micro-droplets observation

Abstract

Shapes of 30 micron-droplets floating on liquid surface is observed. When a microdroplet ejected from a inkjet nozzle impinges on immiscible liquid surface, we can observe the stable shape of floating droplet after 200 μs from the touchdown. We observed the shapes of upper and lower sides of the droplet simultaneously with two microscopes and analyzed the profile of the droplet. Considering the line tension acting on the three-phase contact line, we succeeded in explaining the experimental shape of the floating microdroplet on the liquid surface.