#13 Shaped by Shape: How geometry guides collective behavior

Carpenter ants navigate not just by following pheromones, but by reshaping their environment—building bridges and tunnels from twigs and lianas to move more efficiently. This interaction between motion and environment also appears in active matter systems: collections of self-propelled agents like bacteria or robots that consume energy to move. Previous studies show that active particles can form and reuse paths in cluttered spaces, leading to coordinated, collective behavior. Lattice-based simulations help explore these dynamics using minimal rules. However, spatial discretization may obscure critical particle–environment interactions.

This internship project will explore this question experimentally, using tabletop robots as active particles. The intern will design and construct an arena filled with mobile, 3D-printed obstacles of various shapes. By observing the structures formed by the robots, using video tracking and image analysis, we will investigate how environmental geometry influences collective behavior. The results will be compared with existing computer simulations to highlight which behaviors are robust—ultimately contributing to a better understanding of structure formation in active matter systems.

[1] Dias, C.S., Trivedi, M., Volpe, G. et al. Environmental memory boosts group formation of clueless individuals. Nat Commun 14, 7324 (2023). https://doi.org/10.1038/s41467-023-43099-0

[2] Altshuler, A., Lauber Bonomo, O., Gorohovsky, N., Marchini, S., Rosen, E., Tal-Friedman, O., Reuveni, S., & Roichman, Y. (2024). Environmental memory facilitates search with home returns. Physical Review Research, 6(2), 023255. https://doi.org/10.1103/PhysRevResearch.6.023255