Robust microstructure of self-aligning particles in a simple shear flow

A self-aligning particle (SAP) attains near perfect alignment with the fluid lamellae of a low Reynolds number simple shear flow without application of external torques in contrast with the continuous rotation exhibited by most rigid bodies including thin fibers and disks. We characterize the robustness of the flow alignment of SAPs to secondary perturbations such as flow disturbances, Brownian motion, inter-interparticle interactions, and the presence of a wall using dynamic simulations of ring-shaped SAP geometries. The robust flow alignment of SAPs provides an alternative route to access highly aligned microstructures that are inaccessible to suspensions of traditional particle geometries.