Cell adhesion and proliferation at the surface of liquids such as oil droplets is a surprising phenomenon as it is typically accepted in the field of bioengineering that cells require solid substrates to adhere and to exert mechanical forces required for their spreading and proliferation. Our laboratory recently reported such observations and uncovered that such phenomenon was mediated by a nanoscale (15-20 nm) mechanically strong protein film (nanosheet) assembled at the interface between the two liquids. However, little is known of the morphology and structure of such protein nanosheet and the impact of such structure on their mechanics, and in turn cell behaviour. This project aims to explore the structure of protein nanosheets assembled at analogous air-water interfaces, in situ.