Room-Temperature Self-Healing Cholesteric Liquid Crystal Elastomer with Mechanochromism and Tunable Circularly Polarized Reflection

Abstract

Cholesteric Liquid Crystal Elastomers (CLCE) are attracting attention for their controllable nanoscale helical reflective structures without requiring complex nanofabrication. However, their practical applications are limited by their robust covalent cross-linked networks. To address this, we introduce dynamic covalent boronate ester bonds into the CLCE network, creating a novel class of CLCE. This new material shows a reflection band shift from 600 nm to 520 nm under mechanical stress and excellent reversibility in stretching cycles. Notably, beyond 40% strain, the single circularly polarized reflection transitions to dual reflections. In addition, CLCE exhibit excellent self-healing ability with self-healing rates of 85.83%±7.92% and 89.63%±4.30% after 24 h at room temperature or 90 °C, respectively, and can support loads up to 1500 times its weight. This work offers a simple method for fabricating photonic crystal films with wide-range mechanochromic responses, tunable circular polarization selectivity, and efficient self-healing, promising applications in smart photonic camouflage and adaptive optical systems.