(358i) Collective Dynamics of Catalytically Self-Propelled Particles
In this research, we first present an analytical solution based on a continuum approach to address the pair interaction of two partially active colloids with arbitrary orientations. Colloids' translational and angular velocities at Stokes flow regime are obtained using Reynolds Reciprocal Theorem (RRT) based on an asymptotic approach in which the net interaction creates a slip-velocity at the surface which actuates the motion. Our analysis indicates two possible scenarios for pair trajectories of catalytic self-propelled particles: either the particles approach, come into contact and assemble or they interact and move away from each other (escape). For motions of the colloids, it is found that the direction of particle rotations is the key factor in determining the escape or assembly scenario. Next, we extend this work to account for many body interactions of a suspension of self-propelled particles by Stokesian Dynamics (SD) simulations. The phoretic interactions between the colloidal motors are short-range and hence can be taken into account in a pairwise additive fashion and the hydrodynamic and Brownian forces are taken into account according to the standard SD. We believe the proposed numerical platform can shed light in our challenging search for a fundamental understanding of reductionist systems in active matter.