Orientational dynamics and rheology of active suspensions in weakly viscoelastic flows

Abstract Microswimmer suspensions in Newtonian fluids exhibit unusual macroscale properties, such as a superfluidic behavior, which can be harnessed to perform work at microscopic scales. Since most biological are non-Newtonian, here we study the rheology of microswimmer suspension weakly viscoelastic shear flow. At individual level, find that stresses generated by activity substantially modify Jeffery orbits well-known from fluids. The orientational dynamics depends on swimmer type; especially pushers resist flow-induced rotation and align an angle with To analyze its impact bulk rheology, dilute presence random tumbling rotational diffusion. Strikingly, elastic response polymeric alter distribution amplify swimmer-induced viscosity. This suggests pusher reach regime lower volume fractions compared fluid identical