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Updated: Dec 13, 2025
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High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
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Pressure-driven changes to spontaneous flow in active nematic liquid crystals
Joshua Walton1, Geoffrey McKay2, Michael Grinfeld1
1Department of Mathematics and Statistics, University of Strathclyde, 26 Richmond Street, G1 1XH, Glasgow, UK.
The European Physical Journal. E, Soft Matter
|August 4, 2020
Summary
A pressure gradient significantly alters spontaneous flow in active nematic liquid crystals within channels. This study reveals how pressure influences flow stability and director orientation, even creating new non-flow states.
Area of Science:
- Soft Matter Physics
- Liquid Crystal Dynamics
- Non-equilibrium Systems
Background:
- Active nematic liquid crystals exhibit spontaneous flows due to internal stresses.
- Channel confinement and boundary conditions (planar anchoring, no-slip) influence flow behavior.
- Understanding active fluid dynamics is crucial for materials science and microfluidics.
Purpose of the Study:
- To investigate the impact of pressure gradients on active nematic liquid crystal flow in channels.
- To analyze how pressure affects spontaneous flow patterns and director orientation.
- To explore the interplay between activity, pressure, and flow states.
Main Methods:
- Utilizing a model based on Ericksen-Leslie theory with active stress.
- Directly solving the flow equation and obtaining asymptotic solutions for the director angle.
- Numerically solving full nonlinear equations to examine equilibria and stability.
Main Results:
- Pressure gradients disrupt the inherent symmetries of flow solutions (symmetric/antisymmetric).
- New branches of stable and unstable equilibria emerge, some disconnected from the no-flow state.
- For sufficiently large pressure gradients, non-trivial director angle solutions exist across all activity values.
Conclusions:
- Pressure gradients are a critical factor in controlling active nematic flows in confined geometries.
- The study predicts the behavior of different solution types in the activity-pressure state space.
- This work offers insights into designing and manipulating active soft matter systems.
Keywords:
Flowing Matter: Active Fluids
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