Dynamics of slender chemically-propelled filaments

Chemically-propelled particles are an artificial prototype for active matter. These submerged objects self-propel by consuming a fuel in the surrounding fluid: surface chemical reactions alter the local solute concentration, and solute-surface interactions cause any resulting concentration gradients to drive slip flows across its surface. The subsequent propulsion depends on both the swimmer geometry and the chemical patterning across its surface. 

I will present recent work on Slender Phoretic Theory, which asymptotically simplifies the solute concentration problem to calculating line integrals along the filament’s centreline. We use this theory to expand the library of known solutions, including to looped filaments such as tori and knots. By combining our theory with a model for elastic filaments, we investigate chemoelastohydrodynamic filaments in simulations across a wide range of material stiffnesses. As the filament becomes more deformable, we find that the dynamic behaviour progresses from rigid motion, through buckling and out-of-plane transitions, towards chaos.

Venue: Fulton G20