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Active viscoelastic matter: from bacterial drag reduction to turbulent solids
E J Hemingway1, A Maitra2, S Banerjee3,4
1Department of Physics, Durham University, Science Laboratories, South Road, Durham DH1 3LE, United Kingdom.
Physical Review Letters
|March 21, 2015
Summary
Adding polymers to active nematic liquid crystals creates complex flows but can reduce drag. Active turbulence can emerge in soft solids when activity is introduced.
Area of Science:
- Soft Matter Physics
- Liquid Crystals
- Polymer Rheology
Background:
- Active nematic liquid crystals exhibit spontaneous flow due to internal stresses violating time-reversal symmetry.
- Real-world active fluids often incorporate viscoelastic polymer dynamics alongside liquid crystallinity.
Purpose of the Study:
- To investigate the interplay between active nematic liquid crystals and polymer rheology.
- To understand how polymer additives influence the complex flow behaviors in active matter systems.
Main Methods:
- Coupling a minimal active nematic model with a minimal polymer rheology model.
- Analyzing the resulting fluid dynamics and emergent flow patterns.
Main Results:
- Incorporating polymers increases the complexity of spontaneous flow patterns in active nematics.
- Polymers can induce a drag-reduction effect, enhancing net flow throughput in confined geometries.
- Active turbulence can be triggered in soft elastomeric solids by introducing activity.
Conclusions:
- Polymer rheology significantly modifies the behavior of active nematic liquid crystals.
- Active nematics with polymers offer tunable properties for controlling fluid flow and emergent phenomena.
- This work provides insights into the design of active materials with desired flow characteristics.
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