Spatiotemporal Programmability of 3D Chiral Color Units Driven by Ink Spontaneous Diffusion toward Customized Printing

Adv Mater. 2024 Nov 19:e2411988. doi: 10.1002/adma.202411988. Online ahead of print.

Abstract

Blue phase liquid crystals (BPLCs) have exhibited promising applications in 3D flexible displays due to their molecular-level self-assembled chiral structures, fast response, and tunable polarized colors. However, there remain challenges for spatiotemporal programming of 3D chiral color units for BPLC dynamic patterning. Herein, the programmable temporal evolution of micrometer-scale color units and spatial configuration switch of chiral modes are achieved by spontaneous ink diffusion-driven asymmetric lattice deformation in dual-chiral polymer-templated blue phases. Custom-printed colorful patterns are designed by machine learning-assisted parameter optimization, which displays programmable multidimensional encrypted information that incorporates temporal evolving colors (wavelength), spatial distribution (depth), chiral modes (L/R). The quantitative relationship between ink diffusion kinetics and blue-phase dynamic 3D structural optics is established by in situ characterization, finite element analysis, and mathematical geometry modeling. This work provides insights into the microgeometric manipulation of 3D chiral color of BPLCs in the application of information security and self-adaptive indicators.

Keywords: blue phase liquid crystals; dynamic color control; ink‐diffusion; multiple chiral encryptions, programmable patterning.