Title: Programmable Coloration and Patterning on Reconfigurable Chiral Photonic Paper

Author: Shuzhen Cui, Lang Qin, Xiaojun Liu, Yanlei Yu*

Journal: Adv. Optical Mater., 2022, 10(5), 2102108

Abstract:

Responsive photonic crystals are widely employed to construct rewritable paper, where patterns are written and erased repeatedly via color switching. The working principle mainly lies in the changes on the lattice constant of periodic structures, which, however, restricts the localized color tuning of the recorded patterns and thus limits multicolor information transfer. Herein, a novel strategy is reported to write, erase, and importantly to tune the colors by developing unique light-driven cholesteric liquid crystals (CLCs) that possess self-organized helical superstructures with two structural elements of pitch lengths (lattice constant) and helical axes (reconfiguration). Recon-figuration of the helical axes provides two high-contrast optical states for writing and erasing by pressure and electricity, whereas precise photocontrol of the pitch lengths contributes to localized color tuning. These features primarily capitalize on the light-driven CLC with diverse photostationary colors, which is induced by a newly designed binary chiral system and confined in the polymer dispersed liquid crystal layer. Distinct multicolor patterns are mechanically written, optically tuned, and electrically erased on the rewritable photonic paper in a programmable manner. Such photonic paper has potential to record, program, and remember optically addressed images in visualized color information and user-interactive display technologies.

论文链接：https://onlinelibrary.wiley.com/doi/full/10.1002/adom.202102108

PDF下载：Programmable Coloration and Patterning on Reconfigurable Chiral Photonic Paper.pdf

已报道的可重写光子纸通过调节光子晶体周期结构的晶格常数这个唯一变量来显示颜色，进而实现图案的写入-擦除，然而，该图案的颜色无法改变。为解决该问题，本文利用聚合诱导相分离技术，将光响应胆甾相液晶和聚合物分散液晶（Polymer dispersed liquid crystals，PDLC）结合，开发了一种具有手写、电擦、光调色功能的光子纸。这些功能取决于光子纸内部的PDLC层，该层结构由光响应胆甾相液晶微滴和聚合物网络组成。当用笔在光子纸上书写时，压力使胆甾相液晶的螺旋轴从散射光的无序焦锥态重构为反射光的有序平面态，图案被写入；利用光刺激调控胆甾相液晶的螺距变化，写入的图案会从单色变为多彩状态；施加电场后，螺旋轴重构为焦锥态，图案被擦除。值得注意的是，我们设计的新型光子纸功能得到了升级，由简单的“写入-擦除”升级为“写入-调色-擦除”和“调色-写入-擦除”两种工作模式。在用户交互式显示技术中，这种新型光子纸在记录、编程和记忆复杂多色信息等方面具有应用潜力。