# Solvent Evaporation-Induced Self-Assembly of Flexible Cholesteric Liquid Crystal Elastomers: Fabrication, Performance Tuning, and Optimization

## TL;DR

This paper introduces a new fabrication method for flexible liquid crystal elastomers that can change color across a wide range when stretched.

## Contribution

The novel SEISA method enables broad wavelength tunability and defect minimization in DCLCEs with controllable structural coloration.

## Key findings

- DCLCEs fabricated using SEISA show a tunable bandwidth of up to 209 nm across the visible spectrum.
- Stretching the material to 2.8 times its original length shifts the center wavelength from 613 nm to 404 nm.
- The process optimization includes factors like chiral dopant amount, UV exposure, and coating parameters.

## Abstract

The realization of broad-wavelength tunability of the structural color in Double layered Cholesteric Liquid Crystal Elastomers (DCLCEs), along with good flexibility and processability, presents a significant challenge. This research introduces a facile and effective fabrication technique, Solvent Evaporation-Induced Self-Assembly (SEISA), for the production of DCLCEs exhibiting broad wavelength tunability, superior flexibility, and robust mechanical characteristics. Focusing on initial color tuning, bubble defect minimization, UV photopolymerization, and coating procedures, this research systematically optimizes the fabrication process through experimental investigation of factors like chiral dopant amount, temperature, UV exposure duration, coating thickness, and speed. The method enabled the successful fabrication of DCLCEs with uniform and controllable coloration, demonstrating the effectiveness of this controlled synthesis approach in significantly enhancing structural color features. Upon stretching to 2.8 times its original length, the center wavelength shifted from 613 nm to 404 nm, yielding a tunable bandwidth of up to 209 nm across the visible spectrum.