Study of detailed balance in an active matter system through Multicellular magnetotactic bacteria

Multicellular magnetotactic bacteria (MMB) align with the geomagnetic field, enabling them to navigate through sediment. When directed at a hard surface, an MMB is rapidly rotated away by contact forces at some random angle, so it can reorient to get around obstacles. This random reorientation, coupled with deterministic alignment with the magnetic field, causes the concentration of MMB to decay with distance from hard surfaces.

The fact that we can tune MMB's decay length by varying magnetic field strength, allows for the comparison of these dynamics with an ideal gas in a gravitational field. We track the motion of MMB through microfluidic chambers consisting of a large pore connected with a chain of small pores, similar to Pascal's communicating vessels as seen in thermodynamics.

The distribution of MMB adhering to or breaking detailed balance, determines the applicablity of an isotropic pressure to an active matter system.