(266e) Co-Rotating, Counter-Rotating, and Frustrated Swarms of Microswimmers Under Confinement

Microswimmers with off-center interaction sites exhibit rich collective dynamics, forming polar swarms in unbounded domains with periodic boundary conditions. In this study, we explore how confinement alters these emergent behaviors by placing the swimmers in geometries composed of overlapping circular boundaries. We consider two distinct confinement topologies: (1) a figure-eight domain formed by two overlapping circles, and (2) a triangular arrangement of three overlapping circles with centers at the vertices of an equilateral triangle. In the figure-eight geometry, the swarm exhibits either co-rotating or counter-rotating motion in the two lobes, depending on overlap, initial conditions, and interaction strengths. In the triangular configuration, more complex behaviors emerge, including dynamic frustration and fluctuating collective patterns. Our findings reveal how geometry and topological constraints can be used to control and steer active matter, offering insights into the design of microscale robotic swarms and synthetic active systems.