Many biological fluids are polymer solutions, whose viscoelasticity can enhance cell swimming and promote large-scale mixing.
We showed that the core-shell organization also arises in polymer solutions, but with fascinating additional flow fluctuations. [7/8]

Surprisingly, when the droplets are big and concentrated, the cells self-organize into a concentrated inner "core" of immotile cells surrounded by a more dilute outer "shell" of highly motile cells. (See movie in 1st tweet.) In some cases, the core shrinks and disappears. [3/8]

Excited to release our latest work:
doi.org/10.1101/2025...

Here, we describe how confined bacterial suspensions self-organize into structured domains of different motilities, in response to oxygen limitations🦠🍥

Bluetorial follows! [1/8]