Emergent Stripes of Active Rotors in Shear Flows.

The shear-induced reversible self-organization of active rotors into strip-like aggregates is studied by carrying out computational simulations. The numerical and theoretical results demonstrate that the average width of the strips is linearly dependent on the relative intensity of active torque to the shear rate of the imposed flow. In the particle strips, edge flows are observed to be against the imposed flow and play a crucial role to maintain the stability of the strips. Additionally, the rheological result shows the dependence of shear and rotational viscosities on the active torque direction and the oddness of normal stress response. By exhibiting a novel collective phenomenon of active rotors, our study paves the way of understanding the chiral active matter.