Feedback and reactive flow effects on living crystal formation

Active spherical particles in a water film form aggregate on two neighboring water bubbles, where one of the bubbles' half surface is heated by a laser source, creating a convective flow field. The specific geometry is similar to the experimental setup we used for colloidal particles (Ilday et al., 2017). Water flow is considered reactive during the simulation due to changing flow field, as well as temperature field. A feedback interaction is introduced, which may be due to the concentration of particles in some region of fluid, effectively a time-dependent accumulation. We show the effect of attractive and repulsive feedback forces, and observe, under attractive feedback, the formation of patches of aggregate distributed all over the space, and eventually a greater aggregate formation on the bubble surface. Reactive flow effects, with and without feedback effects, are analyzed, by examining the pair correlation and mean square displacement indicators, as well as the single-particle trajectories. (C) 2021 Elsevier B.V. All rights reserved.