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Phase patterning of liquid crystal elastomers by laser-induced dynamic crosslinking

Abstract

Liquid crystal elastomers hold promise in various fields due to their reversible transition of mechanical and optical properties across distinct phases. However, the lack of local phase patterning techniques and irreversible phase programming has hindered their broad implementation. Here we introduce laser-induced dynamic crosslinking, which leverages the precision and control offered by laser technology to achieve high-resolution multilevel patterning and transmittance modulation. Incorporation of allyl sulfide groups enables adaptive liquid crystal elastomers that can be reconfigured into desired phases or complex patterns. Laser-induced dynamic crosslinking is compatible with existing processing methods and allows the generation of thermo- and strain-responsive patterns that include isotropic, polydomain and monodomain phases within a single liquid crystal elastomer film. We show temporary information encryption at body temperature, expanding the functionality of liquid crystal elastomer devices in wearable applications.

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Fig. 1: The LIDC process.
Fig. 2: Modulation of optical and phase transition properties of LCEs through LIDC.
Fig. 3: MD simulations.
Fig. 4: Repeatability of LIDC and thermal-stimulus-responsive properties of patterned LCEs.
Fig. 5: Demonstration of human-related/skin-attachable applications of LCEs.

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Data availability

All data supporting the findings of this study are available within this Article and its Supplementary Information. Additional raw data generated in this study are available from the corresponding author upon reasonable request.

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Acknowledgements

This work was supported by the National Research Foundation of Korea (grant number 2021R1A2B5B03001691).

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Authors and Affiliations

Authors

Contributions

S.H.C. proposed the research idea. J.H.K. synthesized the RAFT agent. S.H.C. and S.H.K. designed the experiments. S.H.C. performed the experiments and post-processed the data. S.H.C. and J.A. conducted the MD simulations. T.K., Y.J., D.W., J.B., K.R.P., S.J., H.K. and Y.G.K. advised on implementing research ideas and assisted with the experimental set-up. S.H.C. and S.H.K. wrote the paper. S.H.K. supervised the research.

Corresponding author

Correspondence to Seung Hwan Ko.

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Peer review information

Nature Materials thanks Yanjun Liu and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Notes 1–7, Figs. 1–30, Tables 1 and 2 and video captions.

Supplementary Video 1

Optical property variation of patterned LCE with temperature.

Supplementary Video 2

Three-phase patterned LCE and simultaneous use of visibility patterning and actuation.

Supplementary Video 3

On-demand temporary encryption of the pattern via body temperature.

Supplementary Video 4

On-demand temporary encryption of the pattern via mechanical stretching.

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Choi, S.H., Kim, J.H., Ahn, J. et al. Phase patterning of liquid crystal elastomers by laser-induced dynamic crosslinking. Nat. Mater. (2024). https://doi.org/10.1038/s41563-024-01845-9

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