Hydrodynamics of slender swimmers near deformable interfaces

We study the coupled hydrodynamics between a force- and torque-free slender microswimmer and an interface with a deformation that is influenced by both surface tension and bending elasticity. For an interface separating two fluids with arbitrary viscosities, the role of the swimmer orientation, the fluid and interface properties on the swimmer migration is examined. The nature of the short-time swimmer migration depends crucially on its orientation and the fluid viscosity ratio. When a swimmer is in the more viscous fluid and parallel or perpendicular to the interface, the short-time swimmer migration is opposite to that of the long-time migration.