Thin free-standing liquid films manipulation

This paper explores the dynamics of thin free-standing liquid film by introducing a device to manip-<br>ulate its shape. We used a Teflon (hydrophobic) bubble pipe with a ∼ 0.75 mm high Au-Pt sputter<br>coating (hydrophilic) on the inner surface that prevents a water-based film from traveling when air is<br>pumped to inflate or deflate the film. In this way, we can reversibly drive flow regime switch between<br>viscous-capillary and viscous-gravity. The device is coupled with a digital holography setup to real<br>time-measure the film thickness map evolution. The experimental setup is used to measure liquid<br>film drainage dynamics in different regimes, to stabilize films which typically quickly tend to rupture,<br>to obtain their solidification with solvent evaporation and to induce film structuring by periodic film<br>manipulation. We believe this device represents a useful and practical tool to study thin liquid film<br>dynamics and to produce novel (patterned) 2D structures for the numerous scientific and technical<br>fields where they are of use