Electrically driven nematic flow in microfluidic capillary with radial temperature gradient

Area of Science:

• Physics
• Fluid Dynamics
• Materials Science

Background:

• Microsized nematic liquid crystal volumes exhibit complex director field behavior.
• Interactions between electric fields, director gradients, and temperature gradients can induce unique fluid dynamics.

Purpose of the Study:

• To describe an electrically driven fluid pumping principle based on kinklike director field distortions.
• To investigate the influence of electric fields and boundary curvature on these distortions and fluid flow.

Main Methods:

• Theoretical analysis of interactions within a homogeneously aligned liquid crystal microfluidic channel.
• Modeling of kinklike distortion waves under radial electric fields and temperature gradients.
• Numerical calculations to determine parameter dependencies.

Main Results:

• Kinklike distortion waves are excited by the interplay of electric fields, director gradients, and temperature gradients.
• The wave's appearance is contingent on the radial electric field strength and boundary curvature.
• A nonstandard pumping regime with maximum flow near the hot cylinder was identified for specific voltage and curvature values.

Conclusions:

• Electrically driven fluid pumping is achievable through controlled director field distortions in nematic liquid crystals.
• Parameter tuning allows for novel fluid manipulation, including directional flow enhancement.
• This research opens possibilities for advanced microfluidic devices and actuators.