Investigating the collective motion of nematodes (Turbatrix aceti) inside a flexible boundary​

Vinegar eels (Turbatrix aceti) are microscopic nematodes that can synchronize their body oscillations to produce a collective metachronal wave. In this coordinated state, the nematodes are able to produce a strong pushing force that we leverage to study the behavior of active matter at a flexible boundary. We use interfacial tension between two liquids to simulate the flexible boundary. We find several states that have been previously predicted in simulations, such as a periodic deformation of the border and a collectively moving droplet. We also discovered a new unique state where the nematodes are capable of creating long protrusions. We analyze the different states that we found as a function of nematode density and the interfacial tension of the liquids.