MEAM Seminar: “Interfacial Soft Matter”

Surface tension plays a critical role in a wide range of biological, environmental, technological and geophysical settings. In this talk, I will present three different problems dealing with interfacial soft matter that find motivation in markedly diverse areas. First, I will discuss the evaporation kinetics and flow dynamics of non-spherical sessile drops undergoing phase change. While previous investigations have been restricted to axisymetric drops, I will illustrate a number of new geometry-induced effects emerging from consideration of a range of non-spherical drops. Second, I will describe the non-equilibrium dynamics and statistical behavior of a hydrodynamic pilot-wave system, a liquid drop self-propelling on the surface of a vibrating fluid bath through a resonant interaction with its own wave field. In particular, I will consider the wave-mediated interaction of this active system with variable bottom topography to illustrate the emergence of wavelike statistics around defects, and spontaneous collective order and phase transitions in spin lattices. The final part of this talk will deal with active colloids. Specifically, I will consider the realignment of a Janus drop, a double-emulsion drop formed by two immiscible fluids, in response to an externally-imposed temperature gradient. The development of dynamically reconfigurable microlenses based on this mechanism will also be discussed.