Dynamic mode structure of active turbulence

The collective motion of dense suspensions of swimming bacteria is typical of a broad class of active materials, which serve an array of important biological and ecological functions. This work combines microfluidic experiments with modal analysis, typically reserved for inertial turbulence, to quantify the active turbulence of bacterial suspensions. Our results unveil the underlying constituent flow structures responsible for the interactions of chaotic bacterial motion with solid boundaries and external flows, and establish an analysis framework to facilitate new experimental and modeling approaches in active matter systems.