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Updated: Mar 18, 2026
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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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Rheological properties and shear-induced structures of ferroelectric nematic liquid crystals
Ashish Chandra Das1,2, Sathyanarayana Paladugu2, Oleg D Lavrentovich1,2,3
1Materials Science Graduate Program, Kent State University, Kent, OH 44242, USA. olavrent@kent.edu.
Soft Matter
|March 16, 2026
Summary
Shear flow affects ferroelectric nematic (NF) liquid crystals, altering their viscosity and alignment. These findings advance understanding of NF materials and their potential applications.
Area of Science:
- Materials Science
- Soft Matter Physics
- Liquid Crystals
Background:
- Ferroelectric nematic (NF) liquid crystals possess unique polar orientational order.
- Their electric polarization can be controlled by electric fields and surface interactions.
Purpose of the Study:
- To investigate the impact of shear flows on the polarization field and effective viscosity of NF materials.
- To explore the behavior of three specific NF materials (RM734, DIO, FNLC919) under shear.
Main Methods:
- Experimental study of three ferroelectric nematic liquid crystal materials.
- Measurement of effective viscosity across various temperatures and shear rates.
- Observation of director and polarization alignment under shear flow conditions.
Main Results:
- Effective viscosity increases with decreasing temperature, exhibiting Arrhenius behavior except near phase transitions.
- The SmZA phase shows significant shear-rate-dependent viscosity, lower at high shear rates and higher at low shear rates.
- NF materials display shear-thinning at low shear rates (<100 s-1) and near-Newtonian behavior at higher rates.
- Three alignment regimes (flow-alignment, log-rolling, polydomain) were identified based on shear rates.
- NF polarization avoids tilting away from the shear direction, unlike the nematic director, attributed to avoiding splay deformations.
Conclusions:
- The study reveals complex shear-induced behaviors in ferroelectric nematic liquid crystals.
- Understanding these dependencies is crucial for advancing the application of NF materials.
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