Electrokinetic flows in liquid crystal thin films with fixed anchoring

Area of Science:

• Physics
• Materials Science
• Fluid Dynamics

Background:

• Liquid crystalline fluids exhibit unique properties under electric fields.
• Electrokinetics in complex fluids is crucial for microfluidic devices.
• Understanding ionic transport in nematic phases is key to controlling fluid behavior.

Purpose of the Study:

• To investigate ionic and mass transport in nematic liquid crystal films under electrostatic fields.
• To provide analytic and numerical solutions for electrokinetic phenomena in non-uniform director configurations.
• To quantitatively describe charge separation and resulting fluid flows.

Main Methods:

• Analytic and numerical solutions were employed.
• Study focused on thin films with spatially non-uniform nematic directors.
• Investigated configurations including periodic structures and isolated disclinations.

Main Results:

• Quantitative description of mechanisms inducing spatial charge separation.
• Detailed structure and magnitude of resulting electrokinetic flows.
• Fundamental solutions for charge distribution and flow velocities induced by disclinations (m = -1/2, 1/2, 1).

Conclusions:

• The study provides fundamental solutions for electrokinetic flows in nematic liquid crystals.
• Enables analysis of designer flows like 'pusher' flows and particle-induced flows.
• Reveals mechanisms of nonlinear ionic mobilities in response to applied fields.