Droplet impact on freely suspended liquid crystal films

In this project, we propose to study the impact of droplets of liquids with different wetting properties on thin freely suspended liquid-crystalline (LC) films. Such films represent quasi-2D nanostructured liquids, with unique features: Their layered structure guarantees uniform film thickness in quasi-equilibrium, on a molecular scale. It also makes them extremely robust and inhibits drainage, which is in stark contrast to the soap films used for studying impact dynamics. At the same time, smectic films are incredibly flexible, and they exhibit complex surface dynamics, providing unique model systems for studies of thin fluid membranes interacting with impacting or embedded objects. Such films not only allow the investigation of wetting and dewetting in combination with related reversible deformations of the film surfaces, but they can also be used to prepare encapsulated droplets, forming stable liquid-crystalline micro-shells. The primary motivation of the proposal is to understand the coupling between the impact parameters and the dynamic response of the film, at different length scales. The characterisation of microdroplet impact may pave the way for inkjet-printing patterns onto fluid films. By cross-linking or gelling such films, one can prepare submicrometre thick elastic solid membranes.