Heterogeneity-driven collective-motion patterns of active gels

Abstract

Biological swarms produce movement patterns that enhance their viability and functionality. We investigate the importance of internal heterogeneity within a group for the generation and transformation of group movement patterns. We find that an increase in the activity difference between a pair of chemically reactive gels and the rest causes the gel group to evolve from irregular random motion to ordered periodic swing-forward and circular motions. Our results imply that internal heterogeneity within a group is a key factor in generating ordered motion patterns, such as linear or curved locomotion, and disperse or compact population distributions. Dynamical analysis of collective pattern transitions reveals that the location and level of activity of a few “leaders” act as control parameters for bifurcations of collective-motion patterns. Our results suggest a possible origin of swarm motion patterns and may also be used to tailor robot swarms to enhance flexibility and robustness. • The essential role of internal heterogeneity in complex collective motion • Control of transitions between collective-motion patterns in an active group • The relationship between traveling wave dynamics and group motion patterns The generation of spontaneous collective-motion patterns in active groups, such as bird flocks, is a fascinating process. Teng et al. use a chemical model to explore the role of internal heterogeneity, i.e., the existence of a small number of “leaders,” in generating and switching between such patterns, including irregular uncoordinated motion and coordinated swing-forward and circular motions.