Fluid Flows Break Up Microswimmer Clumps

The field of active matter looks at the collective motion of particles and organisms–how birds flock and fish school. In systems of “dry” squirmers–those that have no hydrodynamic interactions with one another–clumps of squirmers can form with empty spaces in between them. This is known as motility-induced phase separation, or MIPS. Researchers wondered whether microswimmers…