Tactic Behaviors in Asymmetric Pacman Particles

Self-asymmetric pacman shaped ${\text{TiO}}_2$ colloids generate motion through degradation of $H_2{O}_2$ . This process is modeled using Computational Fluid Dynamics (CFD) to characterize the response and attempt to understand the swimming orientation. In simulation, using $\mu$ ; the phoretic mobility of the particle, $\kappa$ ; the production rate of the particle and $\alpha$ , the initial angle of the particle, these Pacman particles orientate their bodies according to self-generated fluid flows. Furthermore, the ability of Pacman particles to respond to chemical and light stimuli is studied in experiments. In particular, these particles are able to sense and reorientate their bodies in chemical and light gradients, allowing their motility to guide them in specific directions.