Thermo-Optical Generation of Particle-Like Structures in Frustrated Chiral Nematic Film

Optical Imaging and Analytical Design of Localized Topological Structures in Chiral Liquid Crystals

We combine numerical modeling and analytical design techniques to study several of the most common localized topological structures in frustrated chiral nematic liquid crystal cells. An energy minimization procedure is applied to the lattice model to simulate the director field distributions. These distributions are also approximated using the suitably designed analytical ansatz. We present both simulated and approximated results for optical polarizing microscopy textures and different visualizations of director field structure such as distributions of the azimuthal director angle and isolines for the normal component of the director in coordinate planes. The ansatz correctly mimicked the geometry and optical properties of the solitonic structures under consideration.

Rotation-Time Symmetry Breaking in Frustrated Chiral Nematic Driven by a Pulse-Train Waveform

We report waveform-induced rotation-time symmetry breaking in liquid crystal director motion. Homeotropic cells filled with a negative dielectric anisotropy chiral nematic exhibit persistent and visually observable waves of director orientation with a time period of at least 30 driving field cycles. Their existence in the space of driving waveform parameters is explored. The possibility of utilizing this system, which exhibits both spatial and temporal long-range order, as a modeling tool for experimental studies on discrete time crystals is discussed.

Light-Induced Structures and Microparticle Transportation in a Free-Surface Frustrated Chiral Nematic Film

Local illumination with a light beam leads to thermo-orientational processes in a frustrated chiral nematic film with a free surface. Light-induced hydrodynamic flow and orientational structure create an adaptive platform for the collection, translation and rotation of suspended spherical microparticles. The demonstrated approach has potential applications in soft robotics, micro-object delivery systems, and other micro- and nanotechnologies.

Optical Textures and Orientational Structures in Cholesteric Droplets with Conical Boundary Conditions

Cholesteric droplets dispersed in polymer with conical boundary conditions have been studied. The director configurations are identified by the polarising microscopy technique. The axisymmetric twisted axial-bipolar configuration with the surface circular defect at the droplet’s equator is formed at the relative chirality parameter N0≤2.9. The intermediate director configuration with the deformed circular defect is realised at 2.9<N0<3.95, and the layer-like structure with the twisted surface defect loop is observed at N0≥3.95. The cholesteric layers in the layer-like structure are slightly distorted although the cholesteric helix is untwisted.