Interfaces abound in multiphase materials and living systems. I will highlight my group’s research on modeling the dynamics of soft, fluid-embedded interfaces. Examples include electrohydrodynamic streaming leading to “Saturnian” droplets [1], curvature fluctuations of biomimetic membranes[2], and symmetry-breaking instabilities such as Quincke electrorotation [3], electroconvection[4], and the spontaneous propulsion of droplets enclosing active particles (microswimmers)[5]. These phenomena pose challenging multiscale, multiphysics free-boundary problems. Our approach integrates theory and experiment, developing analytical models that rationalize experimental observations and leveraging experiments to uncover new directions for modeling.

In this talk, I will focus on the dynamics of biomembranes (whose equilibrium shapes minimize the Willmore energy) and discuss how hydrodynamic dissipation within the membrane and its bilayer structure influence membrane remodeling and the statistics of thermally driven fluctuations measured using light, X-ray, or neutron scattering techniques.

References:

[1] Q Brosseau and PM Vlahovska, “Equatorial streaming of a drop in an electric field,” Physical Review Letters 119: 034501 (2017)

[2] HA Faizi, R Granek, PM Vlahovska “Curvature fluctuations of fluid vesicles reveal hydrodynamic dissipation within the bilayer” Proceedings of the National Academy of Sciences 121 (44), e2413557121 (2024)

[3] PF Salipante and PM Vlahovska "Electrohydrodynamics of drops in strong uniform DC electric fields" Physics of Fluids 22: 112110 (2010)

[4] https://gfm.aps.org/meetings/dfd-2025/692e39eba7f805227b16ff55

[5] G Kokot, HA Faizi, G Pradillo, A Snezhko, and PM Vlahovska “Spontaneous Self-propulsion and Nonequilibrium Shape Fluctuations of a Droplet Enclosing Active Particles”, Communications Physics 5: 91 (2022)