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Permeable superelastic liquid-metal fibre mat enables biocompatible and monolithic stretchable electronics

Nature Materials volume 20, pages 859–868 (2021)Cite this article

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Abstract

Stretchable electronics find widespread uses in a variety of applications such as wearable electronics, on-skin electronics, soft robotics and bioelectronics. Stretchable electronic devices conventionally built with elastomeric thin films show a lack of permeability, which not only impedes wearing comfort and creates skin inflammation over long-term wearing but also limits the design form factors of device integration in the vertical direction. Here, we report a stretchable conductor that is fabricated by simply coating or printing liquid metal onto an electrospun elastomeric fibre mat. We call this stretchable conductor a liquid-metal fibre mat. Liquid metal hanging among the elastomeric fibres self-organizes into a laterally mesh-like and vertically buckled structure, which offers simultaneously high permeability, stretchability, conductivity and electrical stability. Furthermore, the liquid-metal fibre mat shows good biocompatibility and smart adaptiveness to omnidirectional stretching over 1,800% strain. We demonstrate the use of a liquid-metal fibre mat as a building block to realize highly permeable, multifunctional monolithic stretchable electronics.

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Fig. 1: Permeable and superelastic LMFM.
Fig. 2: Mechanism of superelasticity of LMFM.
Fig. 3: Stable and self-adaptive superelasticity of LMFMs.
Fig. 4: Biocompatibility of LMFMs.
Fig. 5: Printing and encapsulation of EGaIn-SBS.
Fig. 6: Monolithic stretchable electronics.

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The main data supporting the findings of this study are available from the corresponding author upon request. Source data are provided with this paper.

References

  1. Vatankhah-Varnosfaderani, M. et al. Mimicking biological stress–strain behaviour with synthetic elastomers. Nature 549, 497–501 (2017).

    Article  CAS  Google Scholar 

  2. Rogers, J. A., Someya, T. & Huang, Y. G. Materials and mechanics for stretchable electronics. Science 327, 1603–1607 (2010).

    Article  CAS  Google Scholar 

  3. Kaltenbrunner, M. et al. An ultra-lightweight design for imperceptible plastic electronics. Nature 499, 458–463 (2013).

    Article  CAS  Google Scholar 

  4. Xu, S. et al. Stretchable batteries with self-similar serpentine interconnects and integrated wireless recharging systems. Nat. Commun. 4, 1543 (2013).

    Article  CAS  Google Scholar 

  5. Lipomi, D. J., Tee, B. C. K., Vosgueritchian, M. & Bao, Z. N. Stretchable organic solar cells. Adv. Mater. 23, 1771–1775 (2011).

    Article  CAS  Google Scholar 

  6. Oh, J. Y. et al. Intrinsically stretchable and healable semiconducting polymer for organic transistors. Nature 539, 411–415 (2016).

    Article  CAS  Google Scholar 

  7. Cheng, S. & Wu, Z. G. A microfluidic, reversibly stretchable, large-area wireless strain sensor. Adv. Funct. Mater. 21, 2282–2290 (2011).

    Article  CAS  Google Scholar 

  8. Agarwal, G., Besuchet, N., Audergon, B. & Paik, J. Stretchable materials for robust soft actuators towards assistive wearable devices. Sci. Rep. 6, 34224 (2016).

    Article  CAS  Google Scholar 

  9. Sekitani, T. et al. Stretchable active-matrix organic light-emitting diode display using printable elastic conductors. Nat. Mater. 8, 494–499 (2009).

    Article  CAS  Google Scholar 

  10. Guo, L. A. & DeWeerth, S. P. High-density stretchable electronics: toward an integrated multilayer composite. Adv. Mater. 22, 4030–4033 (2010).

    Article  CAS  Google Scholar 

  11. Jiang, J. K. et al. Fabrication of transparent multilayer circuits by inkjet printing. Adv. Mater. 28, 1420–1426 (2016).

    Article  CAS  Google Scholar 

  12. Tybrandt, K., Stauffer, F. & Voros, J. Multilayer patterning of high resolution intrinsically stretchable electronics. Sci. Rep. 6, 25641 (2016).

    Article  CAS  Google Scholar 

  13. Tybrandt, K. & Voros, J. Fast and efficient fabrication of intrinsically stretchable multilayer circuit boards by wax pattern assisted filtration. Small 12, 180–184 (2016).

    Article  CAS  Google Scholar 

  14. Byun, J. et al. A single droplet-printed double-side universal soft electronic platform for highly integrated stretchable hybrid electronics. Adv. Funct. Mater. 27, 1701912 (2017).

    Article  CAS  Google Scholar 

  15. Huang, G. W. et al. Rapid laser printing of paper-based multilayer circuits. ACS Nano 10, 8895–8903 (2016).

    Article  CAS  Google Scholar 

  16. Miyamoto, A. et al. Inflammation-free, gas-permeable, lightweight, stretchable on-skin electronics with nanomeshes. Nat. Nanotechnol. 12, 907–913 (2017).

    Article  CAS  Google Scholar 

  17. Yang, W. et al. A breathable and screen-printed pressure sensor based on nanofiber membranes for electronic skins. Adv. Mater. Technol. 3, 1700241 (2018).

    Article  CAS  Google Scholar 

  18. Park, S. J. & Tamura, T. Distribution of evaporation rate on human body surface. J. Physiol. Anthropol. 11, 593–609 (1992).

    Article  CAS  Google Scholar 

  19. Fan, J. & Hunter, L. Engineering Apparel Fabrics and Garments (Woodhead Publishing, 2009).

  20. Bucks, D., Guy, R. & Maibach, H. I. in In Vitro Percutaneous Absorption: Principles, Fundamentals, and Applications (eds Bronaugh, R. L. & H. Maibach, I.) Ch. 8 (CRC Press, 1991).

  21. Van der Valk, P. G. & Maibach, H. I. Post-application occlusion substantially increases the irritant response of the skin to repeated short-term sodium lauryl sulfate (SLS) exposure. Contact Dermat. 21, 335–338 (1989).

    Article  Google Scholar 

  22. Bucks, D. & Maibach, H. I. in Percutaneous Absorption: Drugs—Cosmetics—Mechanisms—Methodology 3rd edn (eds Bronaugh, R. L. & Maibach, H. I.) Ch. 4 (Marcel Dekker, 1999).

  23. Kligman, A. M. in The Irritant Contact Dermatitis Syndrome (eds van der Valk, P. G. M. & Maibach, H. I.) Ch. 16 (CRC Press, 1996).

  24. Zhai, H. & Maibach, H. I. Skin occlusion and irritant and allergic contact dermatitis: an overview. Contact Dermat. 44, 201–206 (2001).

    Article  CAS  Google Scholar 

  25. Wei, S. Y. et al. Gas-permeable, irritation-free, transparent hydrogel contact lens devices with metal-coated nanofiber mesh for eye interfacing. ACS Nano 13, 7920–7929 (2019).

    Article  CAS  Google Scholar 

  26. Du, W. Q. et al. Inflammation-free and gas-permeable on-skin triboelectric nanogenerator using soluble nanofibers. Nano Energy 51, 260–269 (2018).

    Article  CAS  Google Scholar 

  27. Zhu, S. et al. Ultrastretchable fibers with metallic conductivity using a liquid metal alloy core. Adv. Funct. Mater. 23, 2308–2314 (2013).

    Article  CAS  Google Scholar 

  28. Gozen, B. A., Tabatabai, A., Ozdoganlar, O. B. & Majidi, C. High-density soft-matter electronics with micron-scale line width. Adv. Mater. 26, 5211–5216 (2014).

    Article  CAS  Google Scholar 

  29. Fassler, A. & Majidi, C. Liquid-phase metal inclusions for a conductive polymer composite. Adv. Mater. 27, 1928–1932 (2015).

    Article  CAS  Google Scholar 

  30. Markvicka, E. J., Bartlett, M. D., Huang, X. & Majidi, C. An autonomously electrically self-healing liquid metal-elastomer composite for robust soft-matter robotics and electronics. Nat. Mater. 17, 618–624 (2018).

    Article  CAS  Google Scholar 

  31. Parida, K. et al. Extremely stretchable and self-healing conductor based on thermoplastic elastomer for all-three-dimensional printed triboelectric nanogenerator. Nat. Commun. 10, 2158 (2019).

    Article  CAS  Google Scholar 

  32. Thrasher, C. J. et al. Mechanoresponsive polymerized liquid metal networks. Adv. Mater. 31, 1903864 (2019).

    Article  CAS  Google Scholar 

  33. Liang, S. et al. Liquid metal sponges for mechanically durable, all-soft, electrical conductors. J. Mater. Chem. C 5, 1586–1590 (2017).

    Article  CAS  Google Scholar 

  34. Varga, M. et al. Adsorbed eutectic gain structures on a neoprene foam for stretchable MRI coils. Adv. Mater. 29, 1703744 (2017).

    Article  CAS  Google Scholar 

  35. Dickey, M. D. Stretchable and soft electronics using liquid metals. Adv. Mater. 29, 1606425 (2017).

    Article  CAS  Google Scholar 

  36. Matsuhisa, N., Chen, X. D., Bao, Z. A. & Someya, T. Materials and structural designs of stretchable conductors. Chem. Soc. Rev. 48, 2946–2966 (2019).

    Article  CAS  Google Scholar 

  37. Diridollou, S. et al. In vivo model of the mechanical properties of the human skin under suction. Skin Res. Technol. 6, 214–221 (2000).

    Article  Google Scholar 

  38. Hendriks, F. M. et al. A numerical-experimental method to characterize the non-linear mechanical behaviour of human skin. Skin Res. Technol. 9, 274–283 (2003).

    Article  CAS  Google Scholar 

  39. Liu, Z. F. et al. Hierarchically buckled sheath-core fibers for superelastic electronics, sensors, and muscles. Science 349, 400–404 (2015).

    Article  CAS  Google Scholar 

  40. Son, W. et al. Highly twisted supercoils for superelastic multi-functional fibres. Nat. Commun. 10, 426 (2019).

    Article  CAS  Google Scholar 

  41. Regan, M. J. et al. X-ray study of the oxidation of liquid-gallium surfaces. Phys. Rev. B 55, 10786–10790 (1997).

    Article  CAS  Google Scholar 

  42. Khan, M. R. et al. Influence of water on the interfacial behavior of gallium liquid metal alloys. ACS Appl. Mater. Interfaces 6, 22467–22473 (2014).

    Article  CAS  Google Scholar 

  43. Yunusa, M., Amador, G. J., Drotlef, D. M. & Sitti, M. Wrinkling instability and adhesion of a highly bendable gallium oxide nanofilm encapsulating a liquid-gallium droplet. Nano Lett. 18, 2498–2504 (2018).

    Article  CAS  Google Scholar 

  44. Guo, C. F. et al. Highly stretchable and transparent nanomesh electrodes made by grain boundary lithography. Nat. Commun. 5, 3121 (2014).

    Article  CAS  Google Scholar 

  45. Lacour, S. P. et al. Stretchable interconnects for elastic electronic surfaces. Proc. IEEE 93, 1459–1467 (2005).

    Article  CAS  Google Scholar 

  46. Yamada, T. et al. A stretchable carbon nanotube strain sensor for human-motion detection. Nat. Nanotechnol. 6, 296–301 (2011).

    Article  CAS  Google Scholar 

  47. Tamayol, A. & Bahrami, M. Transverse permeability of fibrous porous media. Phys. Rev. E 83, 046314 (2011).

    Article  CAS  Google Scholar 

  48. Draize, J. H. Methods for the study of irritation and toxicity of substances applied topically to the skin and mucous membranes. J. Pharmacol. Exp. Ther. 82, 377–390 (1944).

    CAS  Google Scholar 

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Acknowledgements

We acknowledge financial support from the Hong Kong Scholars (no. XJ2016051), Research Grants Council of Hong Kong (PolyU 153032/18P), National Natural Science Foundation of China (grant no. 51872095) and Key R&D Program of Guangzhou (no. 202007020003). We also appreciate the valuable discussion on thermal comfort with J. Fan from The Hong Kong Polytechnic University.

Author information

Authors and Affiliations

  1. Laboratory for Advanced Interfacial Materials and Devices, Research Center for Smart Wearable Technology, Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong SAR, China

    Zhijun Ma, Qiyao Huang, Qiuna Zhuang & Zijian Zheng

  2. State Key Laboratory of Luminescent Materials & Devices, Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, Guangdong Engineering Technology Research and Development Center of Special Optical Fiber Materials and Devices, School of Materials Science and Engineering, South China University of Technology, Guangzhou, China

    Zhijun Ma & Qi Xu

  3. Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong SAR, China

    Xin Zhao & Yuhe Yang

  4. Key Lab of Advanced Technology of Materials of Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, China

    Hua Qiu & Zhilu Yang

  5. Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong SAR, China

    Cong Wang & Yang Chai

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  1. Zhijun Ma
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Contributions

Z.M. and Z.Z. conceived and designed the experiments. Z.M. and Q.X. performed the experiments. Z.M., Q.H. and Q.Z. performed the materials characterization. Z.M. tested the devices’ performances. X.Z., Y.Y., H.Q. and Z.Y. performed the in vivo cell and animal experiments. Z.M. and Q.H. analysed the data. Y.C. and C.W. conducted the numerical model and calculation for the materials. Z.M., Q.H. and Z.Z. wrote the manuscript. Z.Z. supervised the project. All authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to Zijian Zheng.

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The authors declare no competing interests.

Additional information

Peer review information Nature Materials thanks Jaehong Lee, Tsuyoshi Sekitani and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figs. 1–17 and Tables 1 and 2.

Reporting Summary

Supplementary Video 1

This video shows the washing ability of the EGaIn-SBS mat. During the washing, no leakage of liquid metal was observed, and there was no obvious change in the performance of the LED array.

Supplementary Video 2

This video shows the air permeability of the electrospun SBS mat, EGaIn-SBS mat, multilayer EGaIn-SBS mat, PDMS film and Ecoflex film. The samples were wrapped onto a glass tube, through which air was blown into water.

Source data

Source Data Fig. 1

Statistical source data for Fig. 1e, Fig. 1f and Fig. 1h.

Source Data Fig. 3

Statistical source data for Fig. 3a, Fig. 3b and Fig. 3d.

Source Data Fig. 4

Statistical source data for Fig. 4b and Fig. 4c.

Source Data Fig. 5

Statistical source data for Fig. 5e.

Source Data Fig. 6

Statistical source data for Fig. 6d, Fig. 6e, Fig. 6f and Fig. 6h.

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Ma, Z., Huang, Q., Xu, Q. et al. Permeable superelastic liquid-metal fibre mat enables biocompatible and monolithic stretchable electronics. Nat. Mater. 20, 859–868 (2021). https://doi.org/10.1038/s41563-020-00902-3

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