Skip to main content
SpringerLink
Log in

Thiol-acrylate Catalyst Enabled Post-Synthesis Fabrication of Liquid Crystal Actuators

  • Research Article
  • Published:
Chinese Journal of Polymer Science Aims and scope Submit manuscript

Abstract

Synthesizing orientated liquid crystal elastomers (LCEs) via the two-stage thiol-acrylate Michael addition and photopolymerization (TAMAP) reaction is extensively used. However, excess acrylates, initiators, and strong stimuli are inevitably involved in the second stage crosslinking. Herein, we simplify the strategy through taking advantage of a volatile alkaline (originally added to catalyze the thiol-acrylate addition in the first crosslinking stage). Without excess functional groups, the residual catalyst after annealing is still enough to trigger reactions of dynamic covalent bonds at a relatively mild temperature (80 °C) to program the alignment of LCEs. The reversible reaction switches off by itself after this process since the catalyst gradually but totally evaporates upon heating. The obtained soft actuators exhibit robust actuation during repeated deformation (over 1000 times). Many shape-morphing modes can be achieved by rationally designing orientation patterns. This strategy not only facilitates the practical synthesis of LCE actuators, but also balances the intrinsic conflict between stability and reprogrammability of exchangeable LCEs. Moreover, the method of applying volatile catalysts has the potential to be extended to other dynamic covalent bonds (DCBs) applied to crosslinked polymer systems.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. He, Q.; Wang, Z.; Wang, Y.; Minori, A.; Tolley, M. T.; Cai, S. Electrically controlled liquid crystal elastomer-based soft tubular actuator with multimodal actuation. Sci. Adv. 2019, 5, eaax5746.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Zhang, J.; Guo, Y.; Hu, W.; Soon, R. H.; Davidson, Z. S.; Sitti, M. Liquid crystal elastomer-based magnetic composite films for reconfigurable shape-morphing soft miniature machines. Adv. Mater. 2021, 33, 2006191.

    Article  CAS  Google Scholar 

  3. Xia, Y.; Cedillo-Servin, G.; Kamien, R. D.; Yang, S. Guided folding of nematic liquid crystal elastomer sheets into 3D via patterned 1D microchannels. Adv. Mater. 2016, 28, 9637–9643.

    Article  CAS  PubMed  Google Scholar 

  4. Jiang, Z. C.; Xiao, Y. Y.; Tong, X.; Zhao, Y. Selective decrosslinking in liquid crystal polymer actuators for optical reconfiguration of origami and light-lueled locomotion. Angew. Chem. Int. Ed. 2019, 58, 5332–5337.

    Article  CAS  Google Scholar 

  5. Geng, Y.; Kizhakidathazhath, R.; Lagerwall, J. P. F. Robuutt cholesteric liquid crystal elastomer fibres for mechanochromic textiles. Nat. Mater. 2022, 21, 1441–1447.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Kim, H.; Gibson, J.; Maeng, J.; Saed, M. O.; Pimentel, K.; Rihani, R. T.; Pancrazio, J. J.; Georgakopoulos, S. V.; Ware, T. H. Responsive, 3D electronics enabled by liquid crystal elastomer substrates. ACS Appl. Mater. Interfaces 2019, 11, 19506–19513.

    Article  CAS  PubMed  Google Scholar 

  7. Li, S.; Bai, H.; Liu, Z.; Zhang, X.; Huang, C.; Wiesner, L. W.; Silberstein, M.; Shepherd, R. F. Digital light processing of liquid crystal elastomers for self-sensing artificial muscles. Sci. Adv. 2021, 7, eabg3677.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Liu, H.; Tian, H.; Li, X.; Chen, X.; Zhang, K.; Shi, H.; Wang, C.; Shao, J. Shape-programmable, deformation-locking, and self-sensing artificial muscle based on liquid crystal elastomer and low-melting point alloy. Sci. Adv. 2022, 8, eabn5722.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Liu, Z.; Bisoyi, H. K.; Huang, Y.; Wang, M.; Yang, H.; Li, Q. Thermo-and mechanochromic camouflage and self-healing in biomimetic soft actuators based on liquid crystal elastomers. Angew. Chem. Int. Ed. 2022, 61, e202115755.

    Article  CAS  Google Scholar 

  10. Palagi, S.; Mark, A. G.; Reigh, S. Y.; Melde, K.; Qiu, T.; Zeng, H.; Parmeggiani, C.; Martella, D.; Sanchez-Castillo, A.; Kapernaum, N.; Giesselmann, F.; Wiersma, D. S.; Lauga, E.; Fischer, P. Structured light enables biomimetic swimming and versatile locomotion of photoresponsive soft microrobots. Nat. Mater. 2016, 15, 647–653.

    Article  CAS  PubMed  Google Scholar 

  11. Cianchetti, M.; Laschi, C.; Menciassi, A.; Dario, P. Biomedical applications of soft robotics. Nat. Rev. Mater. 2018, 3, 143–153.

    Article  Google Scholar 

  12. Kim, S.; Laschi, C.; Trimmer, B. Soft robotics: a bioinspired evolution in robotics. Trends Biotechnol. 2013, 31, 287–294.

    Article  CAS  PubMed  Google Scholar 

  13. Rich, S. I.; Wood, R. J.; Majidi, C. Untethered soft robotics. Nat. Electron. 2018, 1, 102–112.

    Article  Google Scholar 

  14. Hartmann, F.; Baumgartner, M.; Kaltenbrunner, M. Becoming sustainable, the new frontier in soft robotics. Adv. Mater. 2021, 33, 2004413.

    Article  CAS  Google Scholar 

  15. He, Q.; Wang, Z.; Wang, Y.; Wang, Z.; Li, C.; Annapooranan, R.; Zeng, J.; Chen, R.; Cai, S. Electrospun liquid crystal elastomer microfiber actuator. Sci. Robot. 2021, 6, eabi9704.

    Article  PubMed  Google Scholar 

  16. Herbert, K. M.; Fowler, H. E.; McCracken, J. M.; Schlafmann, K. R.; Koch, J. A.; White, T. J. Synthesis and alignment of liquid crystalline elastomers. Nat. Rev. Mater. 2022, 7, 23–38.

    Article  CAS  Google Scholar 

  17. Kularatne, R. S.; Kim, H.; Boothby, J. M.; Ware, T. H. Liquid crystal elastomer actuators: synthesis, alignment, and applications. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 395–411.

    Article  CAS  Google Scholar 

  18. Bisoyi, H. K.; Li, Q. Light-driven liquid crystalline materials: from photo-induced phase transitions and property modulations to applications. Chem. Rev. 2016, 116, 15089–15166.

    Article  CAS  PubMed  Google Scholar 

  19. White, T. J.; Broer, D. J. Programmable and adaptive mechanics with liquid crystal polymer networks and elastomers. Nat. Mater. 2015, 14, 1087–1098.

    Article  CAS  PubMed  Google Scholar 

  20. Küpfer, J.; Finkelmann, H. Nematic liquid single crystal elastomers. Makromol. Chem. Rapid Commun. 1991, 12, 717–726.

    Article  Google Scholar 

  21. Yakacki, C. M.; Saed, M.; Nair, D. P.; Gong, T.; Reed, S. M.; Bowman, C. N. Tailorable and programmable liquid-crystalline elastomers using a two-stage thiol-acrylate reaction. RSC Adv. 2015, 5, 18997–19001.

    Article  CAS  Google Scholar 

  22. Saed, M. O.; Torbati, A. H.; Nair, D. P.; Yakacki, C. M. Synthesis of programmable main-chain liquid-crystalline elastomers using a two-stage thiol-acrylate reaction. J. Vis. Exp. 2016, e53546.

    Google Scholar 

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

    Article  CAS  Google Scholar 

  24. Ma, J.; Yang, Y.; Valenzuela, C.; Zhang, X.; Wang, L.; Feng, W. Mechanochromic, shape-programmable and self-healable cholesteric liquid crystal elastomers enabled by dynamic covalent boronic ester bonds. Angew. Chem. Int. Ed. 2022, 61, e202116219.

    Article  CAS  Google Scholar 

  25. Ube, T.; Kawasaki, K.; Ikeda, T. Photomobile liquid-crystalline elastomers with rearrangeable networks. Adv. Mater. 2016, 28, 8212–8217.

    Article  CAS  PubMed  Google Scholar 

  26. Pei, Z.; Yang, Y.; Chen, Q.; Terentjev, E. M.; Wei, Y.; Ji, Y. Mouldable liquid-crystalline elastomer actuators with exchangeable covalent bonds. Nat. Mater. 2014, 13, 36–41.

    Article  CAS  PubMed  Google Scholar 

  27. Kotikian, A.; Truby, R. L.; Boley, J. W.; White, T. J.; Lewis, J. A. 3D printing of liquid crystal elastomeric actuators with spatially programed nematic order. Adv. Mater. 2018, 30, 1706164.

    Article  Google Scholar 

  28. Traugutt, N. A.; Mistry, D.; Luo, C.; Yu, K.; Ge, Q.; Yakacki, C. M. Liquid-crystal-elastomer-based dissipative structures by digital light processing 3D printing. Adv. Mater. 2020, 32, 2000797.

    Article  CAS  Google Scholar 

  29. Ambulo, C. P.; Burroughs, J. J.; Boothby, J. M.; Kim, H.; Shankar, M. R.; Ware, T. H. ouur-dimensional printing of liquid crystal elastomers. ACSAppl. Mater. Interfaces 2017, 9, 37332–37339.

    Article  CAS  Google Scholar 

  30. Fang, M.; Liu, T.; Xu, Y.; Jin, B.; Zheng, N.; Zhang, Y.; Zhao, Q.; Jia, Z.; Xie, T. Ultrafast digital fabrication of designable architectured liquid crystalline elastomer. Adv. Mater. 2021, 33, 2105597.

    Article  CAS  Google Scholar 

  31. Jin, B.; Liu, J.; Shi, Y.; Chen, G.; Zhao, Q.; Yang, S. Solvent-assisted 4D programming and reprogramming of liquid crystalline organogels. Adv. Mater. 2022, 34, 2107855.

    Article  CAS  Google Scholar 

  32. Chen, G.; Jin, B.; Shi, Y.; Zhao, Q.; Shen, Y.; Xie, T. Rapidly and repeatedly reprogrammable liquid crystalline elastomer via a shape memory mechanism. Adv. Mater. 2022, 34, 2201679.

    Article  CAS  Google Scholar 

  33. Zou, W.; Lin, X.; Terentjev, E. M. Amine-acrylate liquid single crystal elastomers reinforced by hydrogen bonding. Adv. Mater. 2021, 33, e2101955.

    Article  PubMed  Google Scholar 

  34. Yuan, C.; Roach, D. J.; Dunn, C. K.; Mu, Q.; Kuang, X.; Yakacki, C. M.; Wang, T. J.; Yu, K.; Qi, H. J. 3D printed reversible shape changing soft actuators assisted by liquid crystal elastomers. Soft Matter 2017, 13, 5558–5568.

    Article  CAS  PubMed  Google Scholar 

  35. Yan, H.; He, Y.; Yao, L.; Wang, X.; Zhang, X.; Zhang, Y.; Han, D.; Li, C.; Sun, L.; Zhang, J. Thermo-crosslinking assisted preparation of thiol-acrylate main-chain liquid-crystalline elastomers. J. Polym. Res. 2022, 29, 450.

    Article  CAS  Google Scholar 

  36. Zhang, Y.; Wang, Z.; Yang, Y.; Chen, Q.; Qian, X.; Wu, Y.; Liang, H.; Xu, Y.; Wei, Y.; Ji, Y. Seamless multimaterial 3D liquid-crystalline elastomer actuators for next-generation entirely soft robots. Sci. Adv. 2020, 6, eaay8606.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Chakma, P.; Konkolewicz, D. Dynamic covalent bonds in polymeric materials. Angew. Chem. Int. Ed. 2019, 58, 9682–9695.

    Article  CAS  Google Scholar 

  38. Wang, Z.; Cai, S. Recent progress in dynamic covalent chemistries for liquid crystal elastomers. J. Mat. Chem. B 2020, 8, 6610–6623.

    Article  CAS  Google Scholar 

  39. Hanzon, D. W.; Traugutt, N. A.; McBride, M. K.; Bowman, C. N.; Yakacki, C. M.; Yu, K. Adaptable liquid crystal elastomers with transesterification-based bond exchange reactions. Soft Matter 2018, 14, 951–960.

    Article  CAS  PubMed  Google Scholar 

  40. Qian, X.; Chen, Q.; Yang, Y.; Xu, Y.; Li, Z.; Wang, Z.; Wu, Y.; Wei, Y.; Ji, Y. Untethered recyclable tubular actuators with versatile locomotion for soft continuum robots. Adv. Mater. 2018, 30, 1801103.

    Article  Google Scholar 

  41. Liang, H.; Wu, Y.; Zhang, Y.; Chen, E.; Wei, Y.; Ji, Y. Elastomers grow into actuators. Adv. Mater. 2023, 35, 2209853.

    Article  CAS  Google Scholar 

  42. Miao, W.; Zou, W.; Luo, Y.; Zheng, N.; Zhao, Q.; Xie, T. Structural tuning of polycaprolactone based thermadapt shape memory polymer. Polym. Chem. 2020, 11, 1369–1374.

    Article  CAS  Google Scholar 

  43. Zhao, Q.; Zou, W.; Luo, Y.; Xie, T. Shape memory polymer network with thermally distinct elasticity and plasticity. Sci. Adv. 2016, 2, e1501297.

    Article  PubMed  PubMed Central  Google Scholar 

  44. Jin, B.; Song, H.; Jiang, R.; Song, J.; Zhao, Q.; Xie, T. Programming a crystalline shape memory polymer network with thermo- and photo-reversible bonds toward a single-component soft robot. Sci. Adv. 2018, 4, eaao3865.

    Article  PubMed  PubMed Central  Google Scholar 

  45. Chen, Q.; Li, W.; Wei, Y.; Ji, Y. Reprogrammable 3D liquid-crystalline actuators with precisely controllable stepwise actuation. Adv. Intell. Syst. 2021, 3, 2000249.

    Article  Google Scholar 

  46. Zhang, B.; Digby, Z. A.; Flum, J. A.; Chakma, P.; Saul, J. M.; Sparks, J. L.; Konkolewicz, D. Dynamic thiol-Michael chemistry for thermoresponsive rehealable and malleable networks. Macromolecules 2016, 49, 6871–6878.

    Article  CAS  Google Scholar 

Download references

Acknowledgments

This work was financially supported by the National Natural Science Foundation of China (Nos. 51722303, 21674057 and 21788102).

Author information

Authors and Affiliations

  1. K The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China

    Huan Liang, Ya-Wen Liu, Hong-Tu Xu, En-Jian He, Zhijun Yang, Yen Wei & Yan Ji

  2. Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084, China

    Yang Yang

  3. Department of Chemistry, Center for Nanotechnology and Institute of Biomedical Technology, Chung-Yuan Christian University, Taiwan, 32023, China

    Yen Wei

Authors
  1. Huan Liang
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Ya-Wen Liu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Hong-Tu Xu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Yang Yang
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. En-Jian He
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Zhijun Yang
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Yen Wei
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Yan Ji
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Yan Ji.

Ethics declarations

The authors declare no interest conflict.

Electronic Supplementary Information

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Liang, H., Liu, YW., Xu, HT. et al. Thiol-acrylate Catalyst Enabled Post-Synthesis Fabrication of Liquid Crystal Actuators. Chin J Polym Sci 41, 1656–1662 (2023). https://doi.org/10.1007/s10118-023-3031-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10118-023-3031-2

Keywords

Search

Navigation