Work

Shape-induced alignment and voltage-controlled switching in cholesteric droplets for smart film applications

Year: 2026

Type: article

Abstract: Oblate cholesteric droplets confined in the polymer film can host a toroidal director field with a large nearly uniform region, but the geometric conditions for maximizing this state and its electric-field response were not established. Using simulations and experiments on two polymer-dispersed cholesteric systems with opposite dielectric anisotropy, we show that droplet flattening preserves the toroidal topology and expands the uniformly aligned central region. The optimal structure occurs near relative chirality N 0 ≈ 3 and compression ratio δ ≈ 0.2, where the aligned region reaches a/d ≈ 0.9. These conditions were realized experimentally, yielding dark homeotropic states with a/d ≥ 0.8 at zero field. Under an electric field, droplets with positive dielectric anisotropy switch through a defect-mediated pathway and show rapid color tuning, whereas droplets with negative dielectric anisotropy reorient smoothly and reversibly without twist-wall formation. The results demonstrate that geometric compression can substitute for strong-field reorientation and provide a simple route to reversible electro-optical cholesteric films.

Source: Scientific Reports

DOI: 10.1038/s41598-026-65162-8

Authors: Anna P. Gardymova, Oxana O. Prishchepa, Vladimir Yu. Rudyak, Vadim A. Barbashov, Roman Yu. Kazantsev

Institutions: Krasnoyarsk Scientific Center, Institute of Physics, Siberian Federal University, Tel Aviv University, P.N. Lebedev Physical Institute of the Russian Academy of Sciences

Language: English

Topic: Liquid Crystal Research Advancements

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,690

Funder: Russian Science Foundation