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Updated: Jan 22, 2026
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Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions
Published on: April 19, 2018
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Phase Transition to Large Scale Coherent Structures in Two-Dimensional Active Matter Turbulence.
Moritz Linkmann1, Guido Boffetta2, M Cristina Marchetti3
1Fachbereich Physik, Philipps-Universität of Marburg, D-35032 Marburg, Germany.
Physical Review Letters
|July 9, 2019
Summary
Dense microswimmer suspensions exhibit bacterial turbulence, forming large-scale vortices. A sharp transition to vortex formation indicates a subcritical phase transition separating bacterial and hydrodynamic turbulence in 2D.
Area of Science:
- Fluid dynamics
- Statistical physics
- Soft matter physics
Background:
- Microswimmers in suspension generate collective motion, leading to large-scale vortex patterns termed bacterial turbulence.
- Hydrodynamic turbulence, distinct from bacterial turbulence, operates on larger scales and involves inertial energy transport.
Purpose of the Study:
- Investigate the properties of dense two-dimensional microswimmer suspensions.
- Analyze the transition between bacterial and hydrodynamic turbulence.
Main Methods:
- Utilized a modified Navier-Stokes equation incorporating microswimmer-induced flow forcing.
- Studied dense microswimmer suspensions in a two-dimensional system.
- Examined the role of enstrophy conservation in inverse energy cascades.
Main Results:
- Observed a sharp transition in flow properties, leading to the formation of large-scale vortices.
- Identified an inverse cascade driven by enstrophy conservation, accumulating energy at the largest scales.
- Demonstrated that 2D bacterial and hydrodynamic turbulence are separated by a subcritical phase transition.
Conclusions:
- The collective motion of microswimmers drives a transition to large-scale vortex formation.
- A subcritical phase transition governs the interplay between bacterial and hydrodynamic turbulence in 2D systems.
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