Sorting chiral active Brownian particles with radially modulated optical fields

This study presents a numerical investigation of sorting chiral active Brownian particles using radially modulated optical fields. How these factors affect particle trajectories and spatial distributions is examined by systematically varying particle parameters such as self-propulsion speed, angular velocity, and optical fringe modulation. It is found that the average orbit radius of the particle trajectory strongly depends on the ratio of the self-propulsion speed to the average velocity induced by the moving fringe pattern. In particular, the average orbit radius converges to the theoretical orbit radius defined by the ratio of the self-propulsion speed to the angular velocity in the regime where the self-propulsion speed is greater than the fringe-induced velocity. In mixtures of particles with differing chirality, the dynamic response to circular fringe patterns enables effective classification based on motility. These findings suggest that structured light fields can be used to manipulate and selectively sort chiral active particles, which have potential applications in optical micromanipulation and active matter research.