Three-dimensional soliton-like distortions in flexoelectric nematic liquid crystals: modelling and linear analysis

Earls, Ashley; Calderer, M. Carme

doi:10.1080/02678292.2021.2006812

Cited by 6 publications

(2 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We introduce a butterfly-like irregularity with homeotropic anchoring on the top surface, while the director field is initially uniform along the x -axis. This butterfly configuration is inspired by earlier research 33 and measures 1 × 1. A sinusoidal electric field E = E 0 sin(ω t̃ ) z ^ is applied, with the electric field strength E 0 ranging from 10 to 100, and frequency ω̃ changing from 10 to 800.…”

Section: Discussionmentioning

confidence: 99%

Generation and Propagation of Flexoelectricity-Induced Solitons in Nematic Liquid Crystals

Tang,

Atzin,

Mozaffari

et al. 2024

ACS Nano

View full text Add to dashboard Cite

Solitons in nematic liquid crystals facilitate the rapid transport and sensing in microfluidic systems. Little is known about the elementary conditions needed to create solitons in nematic materials. In this study, we apply a combination of theory, computational simulations, and experiments to examine the formation and propagation of solitary waves, or "solitons", in nematic liquid crystals under the influence of an alternating current (AC) electric field. We find that these solitary waves exhibit "butterfly"-like or "bullet"-like structures that travel in the direction perpendicular to the applied electric field. Such structures propagate over long distances without losing their initial shape. The theoretical framework adopted here helps identify several key factors leading to the formation of solitons in the absence of electrostatic interactions. These factors include surface irregularities, flexoelectric polarization, unequal elastic constants, and negative anisotropic dielectric permittivity. The results of simulations are shown to be in good agreement with our own experimental observations, serving to establish the validity of the theoretical concepts and ideas advanced in this work.

show abstract

Section: Discussionmentioning

confidence: 99%

Generation and Propagation of Flexoelectricity-Induced Solitons in Nematic Liquid Crystals

Tang,

Atzin,

Mozaffari

et al. 2024

ACS Nano

View full text Add to dashboard Cite

show abstract

“…The first attempts to understand the topological structures associated with solitons in liquid crystals took place more than 60 years ago [4,5]. In achiral nematic liquid crystals, solitons can be produced by applying an electric field [6][7][8][9]. After a collision, solitons preserve their shape, thereby providing opportunities for the design of autonomous soft matter microsystems that take advantage of the energy transduction and active transport [10][11][12].…”

mentioning

confidence: 99%

A minimal model of solitons in nematic liquid crystals

Atzin¹,

Mozaffari²,

Tang³

et al. 2022

Preprint

View full text Add to dashboard Cite

Solitons in liquid crystals have generated considerable interest. Several hypotheses of varying complexity have been advanced to explain how they emerge, and a consensus has not emerged yet about the underlying forces responsible for their formation or their structure. In this work, we present a minimal model for soliton structures in achiral nematic liquid crystals, which reveals the key requirements needed to generate traveling solitons in the absence of added charges. These include a surface imperfection or inhomogeneity capable of producing a twist, flexoelectricity, dielectric contrast, and an applied AC electric field that can couple to the director's orientation. Our proposed model is based on a tensorial representation of a confined liquid crystal, and it predicts the formation of "butterfly" structures, quadrupolar in character, in regions of a slit channel where the director is twisted by the surface imperfection. As the applied electric field is increased, solitons (or "bullets") become detached from the wings of the butterfly, which then rapidly propagate throughout the system. The main observations that emerge from the model, including the formation and structure of butterflies, bullets, and stripes, as well as the role of surface imperfections and the strength of the applied field, are consistent with our own experimental findings presented here for nematic LCs confined between two chemically treated parallel plates.

show abstract