Abstract:
Interfacial fluid mechanics, such as the dynamics of drops and bubbles, are important to problems in a variety of fields. For example, the dynamics of drops of complex fluids are important in ink-jet printing and Bloodstain Pattern Analysis; whereas the aerosols formed from bursting bubbles over the ocean can transport pathogens and cloud-condensation nuclei into the atmosphere.  In this talk, I focus on the impact of drops on highly non-wetting solids, such as superhydrophobic surfaces.  Upon impact on these surfaces, a drop will spread and retract so quickly that it can completely leave the surface.  By modifying the surface structure at a variety of scales, the shape of the drop during the bounce can be adjusted, impacting the contact time and surface interaction.  I will show high-speed movies to highlight the phenomena, and I will discuss how experiments and mathematical modeling have given us insight into the underlying physics.