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

Nature Materials volume 23, pages 834–843 (2024)Cite this article

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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.

References

  1. Hu, W., Lum, G. Z., Mastrangeli, M. & Sitti, M. Small-scale soft-bodied robot with multimodal locomotion. Nature 554, 81–85 (2018).

    Article  CAS  PubMed  Google Scholar 

  2. Kim, H. et al. Biomimetic chameleon soft robot with artificial crypsis and disruptive coloration skin. Nat. Commun. 12, 4658 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Na, H. et al. Hydrogel-based strong and fast actuators by electroosmotic turgor pressure. Science 376, 301–307 (2022).

    Article  CAS  PubMed  Google Scholar 

  4. Ware, T. H., McConney, M. E., Wie, J. J., Tondiglia, V. P. & White, T. J. Voxelated liquid crystal elastomers. Science 347, 982–984 (2015).

    Article  CAS  PubMed  Google Scholar 

  5. Kim, H. et al. Biomimetic color changing anisotropic soft actuators with integrated metal nanowire percolation network transparent heaters for soft robotics. Adv. Funct. Mater. 28, 1870220 (2018).

    Article  Google Scholar 

  6. Mura, S., Nicolas, J. & Couvreur, P. Stimuli-responsive nanocarriers for drug delivery. Nat. Mater. 12, 991–1003 (2013).

    Article  CAS  PubMed  Google Scholar 

  7. Song, X. et al. Puffball-inspired microrobotic systems with robust payload, strong protection, and targeted locomotion for on-demand drug delivery. Adv. Mater. 34, 2204791 (2022).

    Article  CAS  Google Scholar 

  8. Deng, Z. et al. Stimuli-responsive conductive nanocomposite hydrogels with high stretchability, self-healing, adhesiveness, and 3D printability for human motion sensing. ACS Appl. Mater. Interfaces 11, 6796–6808 (2019).

    Article  CAS  PubMed  Google Scholar 

  9. Chen, Z. et al. Multiple-stimuli-responsive and cellulose conductive ionic hydrogel for smart wearable devices and thermal actuators. ACS Appl. Mater. Interfaces 13, 1353–1366 (2021).

    Article  CAS  PubMed  Google Scholar 

  10. Osborn, L. E. et al. Prosthesis with neuromorphic multilayered e-dermis perceives touch and pain. Sci. Robot. 3, eaat3818 (2018).

    Article  Google Scholar 

  11. You, I. et al. Artificial multimodal receptors based on ion relaxation dynamics. Science 370, 961–965 (2020).

    Article  CAS  PubMed  Google Scholar 

  12. Davis, D. A. et al. Force-induced activation of covalent bonds in mechanoresponsive polymeric materials. Nature 459, 68–72 (2009).

    Article  CAS  PubMed  Google Scholar 

  13. Yang, Y., Ma, T., Wang, Z. & Lu, Z. Solvent-assisted programming of flat polymer sheets into reconfigurable and self-healing 3D structures. Nat. Commun. 9, 5449 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Boothby, J. M., Kim, H. & Ware, T. H. Shape changes in chemoresponsive liquid crystal elastomers. Sens. Actuators B Chem. 240, 511–518 (2017).

    Article  CAS  Google Scholar 

  15. Han, D. et al. Soft robotic manipulation and locomotion with a 3D printed electroactive hydrogel. ACS Appl. Mater. Interfaces 10, 17512–17518 (2018).

    Article  CAS  PubMed  Google Scholar 

  16. Wang, X. et al. Untethered and ultrafast soft-bodied robots. Commun. Mater. 1, 67 (2020).

    Article  Google Scholar 

  17. Wani, O. M., Zeng, H. & Priimagi, A. A light-driven artificial flytrap. Nat. Commun. 8, 15546 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Kim, Y. S. et al. Thermoresponsive actuation enabled by permittivity switching in an electrostatically anisotropic hydrogel. Nat. Mater. 14, 1002–1007 (2015).

    Article  CAS  PubMed  Google Scholar 

  19. Warner, M. & Terentjev, E. M. Liquid Crystal Elastomers Vol. 120 (Oxford Univ. Press, 2007).

  20. Finkelmann, H., Kock, H. J. & Rehage, G. Investigations on liquid crystalline polysiloxanes 3. Liquid crystalline elastomers — a new type of liquid crystalline material. Makromol. Chem. Rapid Commun. 2, 317–322 (1981).

    Article  CAS  Google Scholar 

  21. Herbert, K. M. et al. Synthesis and alignment of liquid crystalline elastomers. Nat. Rev. Mater. 7, 23–38 (2022).

    Article  CAS  Google Scholar 

  22. Yakacki, C. M. et al. Tailorable and programmable liquid-crystalline elastomers using a two-stage thiol–acrylate reaction. RSC Adv. 5, 18997–19001 (2015).

    Article  CAS  Google Scholar 

  23. Saed, M. O., Gablier, A. & Terentjev, E. M. Exchangeable liquid crystalline elastomers and their applications. Chem. Rev. 122, 4927–4945 (2022).

    Article  CAS  PubMed  Google Scholar 

  24. McBride, M. K. et al. A readily programmable, fully reversible shape-switching material. Sci. Adv. 4, eaat4634 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Pei, Z. et al. Mouldable liquid-crystalline elastomer actuators with exchangeable covalent bonds. Nat. Mater. 13, 36–41 (2014).

    Article  CAS  PubMed  Google Scholar 

  26. Hanzon, D. W. et al. Adaptable liquid crystal elastomers with transesterification-based bond exchange reactions. Soft Matter 14, 951–960 (2018).

    Article  CAS  PubMed  Google Scholar 

  27. Saed, M. O. & Terentjev, E. M. Siloxane crosslinks with dynamic bond exchange enable shape programming in liquid-crystalline elastomers. Sci. Rep. 10, 6609 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Lee, J. H. et al. Robust and reprocessable artificial muscles based on liquid crystal elastomers with dynamic thiourea bonds. Adv. Funct. Mater. 32, 2110360 (2022).

    Article  CAS  Google Scholar 

  29. He, Q., Wang, Z., Wang, Y., Song, Z. & Cai, S. Recyclable and self-repairable fluid-driven liquid crystal elastomer actuator. ACS Appl. Mater. Interfaces 12, 35464–35474 (2020).

    Article  CAS  PubMed  Google Scholar 

  30. He, Q. et al. Electrically controlled liquid crystal elastomer-based soft tubular actuator with multimodal actuation. Sci. Adv. 5, eaax5746 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Liu, H. et al. Shape-programmable, deformation-locking, and self-sensing artificial muscle based on liquid crystal elastomer and low-melting point alloy. Sci. Adv. 8, eabn5722 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Davis, F. J. & Mitchell, G. R. Liquid crystal elastomers: controlled crosslinking in the liquid crystal phase. Polymer 37, 1345–1351 (1996).

    Article  CAS  Google Scholar 

  33. Fowler, H. E., Donovan, B. R., McCracken, J. M., López Jiménez, F. & White, T. J. Localizing genesis in polydomain liquid crystal elastomers. Soft Matter 16, 330–336 (2020).

    Article  CAS  PubMed  Google Scholar 

  34. Mistry, D. et al. Isotropic liquid crystal elastomers as exceptional photoelastic strain sensors. Macromolecules 53, 3709–3718 (2020).

    Article  CAS  Google Scholar 

  35. Scott, T. F., Schneider, A. D., Cook, W. D. & Bowman, C. N. Photoinduced plasticity in cross-linked polymers. Science 308, 1615–1617 (2005).

    Article  CAS  PubMed  Google Scholar 

  36. McBride, M. K. et al. Photoinduced plasticity in cross-linked liquid crystalline networks. Adv. Mater. 29, 1606509 (2017).

    Article  Google Scholar 

  37. Kloxin, C. J., Scott, T. F., Park, H. Y. & Bowman, C. N. Mechanophotopatterning on a photoresponsive elastomer. Adv. Mater. 23, 1977–1981 (2011).

    Article  CAS  PubMed  Google Scholar 

  38. Wang, Z., Tian, H., He, Q. & Cai, S. Reprogrammable, reprocessible, and self-healable liquid crystal elastomer with exchangeable disulfide bonds. ACS Appl. Mater. Interfaces 9, 33119–33128 (2017).

    Article  CAS  PubMed  Google Scholar 

  39. Biggins, J. S., Warner, M. & Bhattacharya, K. Supersoft elasticity in polydomain nematic elastomers. Phys. Rev. Lett. 103, 037802 (2009).

    Article  CAS  PubMed  Google Scholar 

  40. Sánchez‐Ferrer, A. & Finkelmann, H. Polydomain–monodomain orientational process in smectic-C main-chain liquid-crystalline elastomers. Macromol. Rapid Comm. 32, 309–315 (2011).

    Article  Google Scholar 

  41. Azoug, A. et al. Viscoelasticity of the polydomain-monodomain transition in main-chain liquid crystal elastomers. Polymer 98, 165–171 (2016).

    Article  CAS  Google Scholar 

  42. Voter, A. F., Montalenti, F. & Germann, T. C. Extending the time scale in atomistic simulation of materials. Annu. Rev. Mater. Res. 32, 321–346 (2002).

    Article  CAS  Google Scholar 

  43. Perez, D., Uberuaga, B. P., Shim, Y., Amar, J. G. & Voter, A. F. Accelerated molecular dynamics methods: introduction and recent developments. Annu. Rep. Comput. Chem. 5, 79–98 (2009).

    Article  CAS  Google Scholar 

  44. Lian, Q. et al. Toughening mechanism based on the physical entanglement of branched epoxy resin in the non-phase-separated inhomogeneous crosslinking network: an experimental and molecular dynamics simulation study. Polymer 247, 124754 (2022).

    Article  CAS  Google Scholar 

  45. Yang, H. et al. A molecular dynamics study of bond exchange reactions in covalent adaptable networks. Soft Matter 11, 6305–6317 (2015).

    Article  CAS  PubMed  Google Scholar 

  46. Mihai, L. A., Wang, H., Guilleminot, J. & Goriely, A. Nematic liquid crystalline elastomers are aeolotropic materials. Proc. Royal Soc. A Math. Phys. Eng. Sci. 477, 20210259 (2021).

    Google Scholar 

  47. Whitmer, J. K., Roberts, T. F., Shekhar, R., Abbott, N. L. & de Pablo, J. J. Modeling the polydomain-monodomain transition of liquid crystal elastomers. Phys. Rev. E 87, 020502 (2013).

    Article  Google Scholar 

  48. Qian, X. et al. Untethered recyclable tubular actuators with versatile locomotion for soft continuum robots. Adv. Mater. 30, 1801103 (2018).

    Article  Google Scholar 

  49. White, J. L. & Spruiell, J. E. The specification of orientation and its development in polymer processing. Polym. Eng. Sci. 23, 247–256 (1983).

    Article  CAS  Google Scholar 

  50. Bauman, G. E., McCracken, J. M. & White, T. J. Actuation of liquid crystalline elastomers at or below ambient temperature. Angew. Chem. Int. Ed. 61, e202202577 (2022).

    Article  CAS  Google Scholar 

  51. Saed, M. O. et al. Molecularly-engineered, 4D-printed liquid crystal elastomer actuators. Adv. Funct. Mater. 29, 1806412 (2019).

    Article  Google Scholar 

  52. Shaha, R. K., Torbati, A. H. & Frick, C. P. Body-temperature shape-shifting liquid crystal elastomers. J. Appl. Polym. Sci. 138, 50136 (2021).

    Article  CAS  Google Scholar 

  53. Barnes, M., Cetinkaya, S., Ajnsztajn, A. & Verduzco, R. Understanding the effect of liquid crystal content on the phase behavior and mechanical properties of liquid crystal elastomers. Soft Matter 18, 5074–5081 (2022).

    Article  CAS  PubMed  Google Scholar 

  54. Plimpton, S. Fast parallel algorithms for short-range molecular-dynamics. J. Comput. Phys. 117, 1–19 (1995).

    Article  CAS  Google Scholar 

  55. Sun, H. Force-field for computation of conformational energies, structures, and vibrational frequencies of aromatic polyesters. J. Comput. Chem. 15, 752–768 (1994).

    Article  CAS  Google Scholar 

  56. Gissinger, J. R., Jensen, B. D. & Wise, K. E. REACTER: a heuristic method for reactive molecular dynamics. Macromolecules 53, 9953–9961 (2020).

    Article  CAS  Google Scholar 

  57. Stukowski, A. Visualization and analysis of atomistic simulation data with OVITO–the Open Visualization Tool. Model. Simul. Mater. Sci. Eng. 18, 015012 (2010).

    Article  Google Scholar 

  58. Gissinger, J. R., Jensen, B. D. & Wise, K. E. Modeling chemical reactions in classical molecular dynamics simulations. Polymer 128, 211–217 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

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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

  1. Department of Mechanical Engineering, Seoul National University, Seoul, Republic of Korea

    Seok Hwan Choi, Jiyong Ahn, Taegyeom Kim, Yeongju Jung, Daeyeon Won, Junhyuk Bang, Kyung Rok Pyun, Seongmin Jeong, Hyunsu Kim & Seung Hwan Ko

  2. Department of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Seoul, Republic of Korea

    Ju Hee Kim & Young Gyu Kim

  3. Institute of Engineering Research / Institute of Advanced Machinery and Design (SNU-IAMD), Seoul National University, Seoul, Republic of Korea

    Seung Hwan Ko

  4. Interdisciplinary Program in Bioengineering, Seoul National University, Seoul, Korea

    Seung Hwan Ko

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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.

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Correspondence to Seung Hwan Ko.

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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. 23, 834–843 (2024). https://doi.org/10.1038/s41563-024-01845-9

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