Mechanochromic Palettes of Cholesteric Liquid Crystal Elastomers for Visual Signaling

Technical Report · Sat Apr 20 04:00:00 EDT 2024

DOI:https://doi.org/10.2172/2377940· OSTI ID:2377940

Park, Hyewon ^[1]; Lee, Hye Joo ^[2]; Ahn, Hyungju ^[2]; Han, Woong Chan ^[2]; Yun, Hee Seong ^[1]; Choi, Yun-seok ^[3]; Kim, Dae Seok ^[2]; Yoon, Dong Ki ^[1]; Lee, Young-Joo ^[4]

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1. Korea Advanced Inst. Science and Technology (KAIST), Daejeon (Korea, Republic of)
2. Pukyong National Univ., Busan (Korea, Republic of)
3. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
4. Univ. of Pennsylvania, Philadelphia, PA (United States)

Mechanochromic photonic materials present promising prospects for enhancing diverse facets of human life. Cholesteric liquid crystal elastomers (CLCEs) present immediate mechanochromic properties, allowing their utility in various fields, including camouflages, textiles, and anticounterfeiting. Nonetheless, it is essential to provide differentiated color information corresponding to diverse types and degrees of deformation for practical use in real life. Herein, we investigate the mechanochromic responses of CLCEs using their optical rotation under compression and uniaxial stretching. The CLCEs exhibit the same reflection colors indistinguishable for compression and uniaxial stretching due to their contracted pitches. In contrast, the linearly polarized light passing through deformed CLCEs can be modulated by optical rotation, resulting in distinct transmission colors that can be discerned through mechanical deformations. We demonstrate a visual signaling system with color information derived from optical rotation. By comprehending and manipulating the mechanoresponsive behavior of CLCEs, we can advance these materials into innovative solutions with enhanced functionality and performance, thereby broadening their applications for human life enhancement.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States). Center for Integrated Nanotechnologies (CINT)
• Sponsoring Organization: USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA); National Research Foundation of Korea; USDOE Office of Science (SC)
• DOE Contract Number: 89233218CNA000001
• OSTI ID: 2377940
• Report Number(s): LA-UR--23-27756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
cholesteric liquid crystal elastomer
mechanochromic
optical rotation
photonic crystal
visual singaling