Deformation and relaxation of viscous thin films under bouncing drops

Thin, viscous liquid films subjected to impact events can deform. Here we investigate free surface oil film deformations that arise due the air pressure buildup under impacting and rebouncing water drops. Using Digital Holographic Microscopy, measure 3D topography of deformed immediately after drop rebound, with a resolution down 20 nm. We first discuss how is initially during impact, as function thickness, viscosity, speed. Subsequently, describe slow relaxation process rebound. Scaling laws for broadening width decay amplitude perturbations are obtained experimentally found be in excellent agreement results from lubrication analysis. finally arrive at detailed spatio-temporal description