液滴列の衝突による微細孔への液体侵入

抄録

Liquid infiltration is an important process for cleaning inside small size holes. However, it is difficult to infiltrate liquid into closed end holes having small diameter. Because the surface tension prevents the deformation of gas-liquid interface for entering the liquid. In this study, we observed the liquid infiltration process into a closed end hole by applying external pressure under two ways, i.e. gradual pressurization with a hand pump and impingement of a droplet train. As a result, it is found that the amount of dissolved air into liquid by applying pressure is small, and it has small effect for the liquid infiltration. In addition, it is also found that the high liquid infiltration rate can be achieved by applying a droplet train impact. The trapped bubbles inside the holes were ejected by repetition of droplet impingement. On the other hand, such the high liquid infiltration was not observed by the liquid column impact. Possible mechanisms of liquid infiltration by a droplet train impingement are discussed.