Study on the analysis of the vapor-driven solutal Marangoni flow pattern and the mechanism inside a sessile droplet

Abstract

Recently, vapor-driven solutal Marangoni effect has been used as a flow control method inside a sessile droplet. It can be applied in various areas such as particle deposition, droplet interaction, and mixing. Unfortunately, although many researches have been done to applicate it in various areas, there are few researches to investigate and analyze the internal flow pattern theoretically. Therefore, in this thesis, we observe the internal flow pattern by using particle image velocimetry and develop theoretical models to understand the flow. Based on the theoretical models, we predict the internal flow pattern and explain how the flow is generated by vapor-driven solutal Marangoni effect. Furthermore, we show that various internal flow patterns can be generated by the arrangement of the vapor sources, and the flow speed and the time duration of the Marangoni flow can be changed by different volatile liquids.