Active particles in geometric confinement

Active particles, such as swimming bacteria or self-propelled colloids, have the propensity to spontaneously organize into large-scale dynamic structures. Geometric constraints, however, often enforce different spatio-temporal patterns compared to unconfined environment and thus may serve to control active matter behavior. In this talk, I will highlight some recent work from our Lab exploring active particles ( motile colloids powered by Quincke effect, which causes them to spontaneously roll on a surface in the presence of a uniform electric field) in confinement. (1) Quincke rollers enclosed by a soft boundary (a droplet), driving droplet deformation and amoeba-like motility, and (2) dense suspensions of Quincke random walkers and their collective dynamics under strong confinement giving rise to 2D turbulent-like flow.