Directed Autonomous Motion and Chiral Separation of Self-Propelled Janus Particles in Convection Roll Arrays

Abstract

Self-propelled Janus particles exhibit autonomous motion thanks to engines of their own. However, due to randomly changing direction of such motion they are of little use for emerging nano-technological and bio-medical applications. Here, we numerically show that the motion of chiral active Janus can be directed subjecting them to a linear array of convection rolls. Rectification power of self-propulsion motion here can be made more than 60% which is much larger than earlier reports. We show that rectification of chiral Janus particle's motion leads to conspicuous segregation of dextrogyre and levogyre active particles from a racemic binary mixture. Further, we demonstrate how efficiently the rectification effect can be exploited to separate dextrogyre and levogyre particles when their intrinsic torques are distributed with Gaussian statistics.