세미나

An evaporating liquid drop, whether single or multi-component and containing solutes or particulates, leaves a deposit whose form is determined by various parameters, for instance, internal flow fields, liquid compositions, and interactions between suspended particles and a solid substance. Notably, the coffee-ring pattern and the whisky dried mark represent two contrasting results among several dried patterns. This informs us that careful material selection of soft matter is crucial for achieving the desired dried pattern. In this talk, we will show some recent work on the complex soft matter droplet evaporation. The research has been conducted on measuring and understanding the flow field within evaporating solutions based on flow visualization techniques, developing basic models, and conducting research on uniform coating techniques. Particularly, we will introduce various techniques for complete elimination of coffee rings using the Marangoni and capillary effects that occur during the evaporation process of complex liquids. Based on these uniform coating techniques, we will share research results on applications in (a) quantum-dot display components, (b) self-heating plasmonic components, and (c) untra-stretchable liquid metal electrodes. We aim to contribute to the advancement of coating and printing engineering by developing next-generation micro/nano sensors and devices based on uniform coating techniques for complex soft matters.