Hydrodynamics of an odd active surfer in a chiral fluid

Abstract We theoretically and computationally study the low-Reynolds-number hydrodynamics of a linear active microswimmer surfing on compressible thin fluid layer characterized by an odd viscosity. Since underlying three-dimensional is assumed to be very compared any lateral size layer, model effectively two-dimensional. In limit small viscosity even viscosities we obtain analytical expressions for self-induced flow field, which includes non-reciprocal components due On this basis, fully analyze behavior single swimmer, finding that it follows circular path, radius is, leading order, inversely proportional magnitude addition, show pair swimmers exhibits wealth two-body dynamics depends initial relative orientation angles as well propulsion mechanism adopted each swimmer. particular, pusher–pusher pusher–puller-type swimmer pairs exhibit generic spiral motion, while puller–puller found either co-rotate in steady state along trajectory or more complex chaotic resulting from interplay between hydrodynamic steric interactions. Our theoretical predictions may pave way toward better understanding transport chiral fluids with viscosity, find potential applications quantitative microrheological characterization odd-viscous fluids.