Shear migration of chiral particle in parallel-disk

The migration of chiral particles in shear flow is studied by parallel disk rotational rheometer. The chiral particles, made of silicon rubber with its two edges cut, are placed between the disks. When the disk rotates, the chiral particles move not only along the flow direction, but also migrate along the direction perpendicular to the flow (i.e., the radial direction). The migration direction, inner or outer, is determined by the handedness of the particle. This is the first experiment to show that the chiral particles can be separated by the velocity gradient field. The migration velocity is measured as a function of the shear rate, and compared with the result of simulation.