A Toy Story: Active Spheres
This semester, we explore how active sphere develop novel locomotion and collective behaviors across diverse terrains while manipulating topology to form knots and links, discovering new principles for swarm control, navigation, and emergent structure.
Above a critical packing fraction, bare active spheres become trapped whereas spiky active spheres exhibit a new emergent locomotion mode, in which swarm interactions generate sufficient forces to liberate trapped spheres from immobilized states.
Communicative active spheres can perform cyclic pursuit, a canonical benchmark for swarm control, demonstrating decentralized coordination and collective decision-making.
Spiky active spheres can crawl underneath a highly-packed granular monolayer.
Active boundary braiding can create bulk knots and links. The endpoint 2D boundary trajectories provide a complete topological record of the hidden 3D bulk string entangled configuration.