Bacterial fluid flows in thin spherical shells

A dense suspension of motile bacteria confined to a plane can exhibit turbulent-like flow structures due to broken detailed balance at the bacterium scale.~ While bacterial turbulence has been experimentally studied in the plane, relatively little work has addressed~how swarming couples to more complex sample geometries.~ To explore this question, we confine dense suspensions of fluorescent~\textit{E. coli}~within the spherical shell of an oil-bacteria-oil double emulsion, and we then image resultant bacterial fluid flows using confocal microscopy.~ By varying the radius of the double emulsion, we can explore how motile bacterial turbulence couples to curvature.~ Preliminary results suggest that the bacterial turbulence organizes into fluctuating~azimuthal flows, but more work is needed for corroboration of these results. This work is underway and will be reported.~