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Three-dimensional flexible electronics using solidified liquid metal with regulated plasticity

Nature Electronics volume 6, pages 154–163 (2023)Cite this article

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Abstract

Liquid metals based on gallium alloy are of potential use in the development of soft and stretchable electronics due to their intrinsic fluidity and high conductivity. However, it is challenging to build three-dimensional circuits using liquid metals, which limits the complexity and integration of the resulting devices. Here we show that a gallium–indium alloy can be used to fabricate flexible electronics with three-dimensional circuits by exploiting the solid–liquid phase transition and plastic deformation of the liquid metal. Solid but plastically deformable alloy wires are shaped into circuits at low temperatures (under 15 °C) and encapsulated in an elastomer, before being heated above their melting temperature. Subsequently, the supercooling effect allows the alloy to maintain a liquid state at a wide range of temperatures, including below the melting point. We use the technique to fabricate high-sensitivity strain sensors, three-dimensional interconnect arches for integrating an array of light-emitting diodes, and a three-dimensional wearable sensor and multilayer flexible circuit board for monitoring finger motion.

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Fig. 1: Strategy for the fabrication of 3D flexible electronics based on solidified LMs with regulated plasticity.
Fig. 2: Microstructure characterization and performance tests of hypoeutectic Ga–In alloys.
Fig. 3: Electromechanical tests performed on the 2D strain sensor and the design of a high-sensitivity strain sensor with 3D circuit.
Fig. 4: Ga–10In 3D interconnect arch and its example use in an LED array.
Fig. 5: Design and fabrication of 3D structured wearable finger movement detection sensor and multilayer flexible circuit board using Ga–10In solid wire.

Data availability

The data that support the findings of this study are available from the corresponding authors upon reasonable request.

References

  1. Someya, T. & Amagai, M. Toward a new generation of smart skins. Nat. Biotechnol. 37, 382–388 (2019).

    Article  Google Scholar 

  2. Liu, J. et al. Syringe-injectable electronics. Nat. Nanotechnol. 10, 629–636 (2015).

    Article  MathSciNet  Google Scholar 

  3. Man, K. & Damasio, A. Homeostasis and soft robotics in the design of feeling machines. Nat. Mach. Intell. 1, 446–452 (2019).

    Article  Google Scholar 

  4. Bartlett, D. B. et al. High thermal conductivity in soft elastomers with elongated liquid metal inclusions. Proc. Natl Acad. Sci. USA 114, 2143–2148 (2017).

    Article  Google Scholar 

  5. Lim, H. R. et al. Advanced soft materials, sensor integrations, and applications of wearable flexible hybrid electronics in healthcare, energy, and environment. Adv. Mater. 32, 1901924 (2020).

    Article  Google Scholar 

  6. Ling, Y. et al. Disruptive, soft, wearable sensors. Adv. Mater. 32, 1904664 (2020).

    Article  Google Scholar 

  7. Khang, D. Y., Huang, Y. & Rogers, J. A. A stretchable form of single-crystal silicon for high-performance electronics on rubber substrates. Science 311, 208–212 (2006).

    Article  Google Scholar 

  8. Wang, Y. et al. A highly stretchable, transparent, and conductive polymer. Sci. Adv. 3, 1602076 (2017).

    Article  Google Scholar 

  9. Gao, N. et al. Crystal-confined freestanding ionic liquids for reconfigurable and repairable electronics. Nat. Commun. 10, 547 (2019).

    Article  Google Scholar 

  10. Liu, Y. et al. Soft and elastic hydrogel-based microelectronics for localized low-voltage neuromodulation. Nat. Biomed. Eng. 3, 58–68 (2019).

    Article  Google Scholar 

  11. Ma, Z. et al. Permeable superelastic liquid-metal fibre mat enables biocompatible and monolithic stretchable electronics. Nat. Mater. 20, 859–868 (2021).

    Article  Google Scholar 

  12. Zhou, L. Y., Fu, J. Z., Gao, Q., Zhao, P. & He, Y. All‐printed flexible and stretchable electronics with pressing or freezing activatable liquid‐metal–silicone inks. Adv. Funct. Mater. 30, 1906683 (2019).

    Article  Google Scholar 

  13. Leber, A. et al. Soft and stretchable liquid metal transmission lines as distributed probes of multimodal deformations. Nat. Electron. 3, 316–326 (2020).

    Article  Google Scholar 

  14. Kim, M. G., Alrowais, H., Pavlidis, S. & Brand, O. Size-scalable and high-density liquid-metal-based soft electronic passive components and circuits using soft lithography. Adv. Funct. Mater. 27, 1604466 (2017).

    Article  Google Scholar 

  15. Yun, G. et al. Liquid metal composites with anisotropic and unconventional piezoconductivity. Matter 3, 824–841 (2020).

    Article  Google Scholar 

  16. Kim, M. G., Brown, D. K. & Brand, O. Nanofabrication for all-soft and high-density electronic devices based on liquid metal. Nat. Commun. 11, 1002 (2020).

    Article  Google Scholar 

  17. Liu, S., Shah, D. S. & Kramer-Bottiglio, R. Highly stretchable multilayer electronic circuits using biphasic gallium-indium. Nat. Mater. 20, 851–858 (2021).

    Article  Google Scholar 

  18. Dong, C. et al. High-efficiency super-elastic liquid metal based triboelectric fibers and textiles. Nat. Commun. 11, 3537 (2020).

    Article  Google Scholar 

  19. Marques, D. G., Lopes, P. A., Almeida, A. T. D., Majidib, C. & Tavakoli, M. Reliable interfaces for EGaIn multi-layer stretchable circuits and microelectronics. Lab Chip 19, 897–906 (2019).

    Article  Google Scholar 

  20. Boley, J. W., White, E. L., Chiu, G. T. C. & Kramer, R. K. Direct writing of gallium-indium alloy for stretchable electronics. Adv. Funct. Mater. 24, 3501–3507 (2014).

    Article  Google Scholar 

  21. Park, J. E., Kang, H. S., Koo, M. & Park, C. Autonomous surface reconciliation of a liquid-metal conductor micropatterned on a deformable hydrogel. Adv. Mater. 32, 2002178 (2020).

    Article  Google Scholar 

  22. Pan, C. et al. Visually imperceptible liquid-metal circuits for transparent, stretchable electronics with direct laser writing. Adv. Mater. 30, 1706937 (2018).

    Article  Google Scholar 

  23. 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  Google Scholar 

  24. Boley, J. W., White, E. L. & Kramer, R. K. Mechanically sintered gallium-indium nanoparticles. Adv. Mater. 27, 2355–2360 (2015).

    Article  Google Scholar 

  25. Li, X. et al. Evaporation-induced sintering of liquid metal droplets with biological nanofibrils for flexible conductivity and responsive actuation. Nat. Commun. 10, 3514 (2019).

    Article  Google Scholar 

  26. Gao, Y. et al. Wearable microfluidic diaphragm pressure sensor for health and tactile touch monitoring. Adv. Mater. 29, 1701985 (2017).

    Article  Google Scholar 

  27. Yeo, J. C., Yu, J., Koh, Z. M., Wang, Z. & Lim, C. T. Wearable tactile sensor based on flexible microfluidics. Lab Chip 16, 3244–3250 (2016).

    Article  Google Scholar 

  28. Teng, L. et al. Liquid metal-based transient circuits for flexible and recyclable electronics. Adv. Funct. Mater. 29, 1808739 (2019).

    Article  Google Scholar 

  29. Ladd, C., So, J. H., Muth, J. & Dickey, M. D. 3D printing of free standing liquid metal microstructures. Adv. Mater. 25, 5081–5085 (2013).

    Article  Google Scholar 

  30. Park, Y.-G., An, H. S., Kim, J. Y. & Park, J. U. High-resolution, reconfigurable printing of liquid metals with three-dimensional structures. Sci. Adv. 5, 2844 (2019).

    Article  Google Scholar 

  31. Gannarapu, A. & Gozen, B. A. Freeze-printing of liquid metal alloys for manufacturing of 3D, conductive, and flexible networks. Adv. Mater. Technol. 1, 1600047 (2016).

    Article  Google Scholar 

  32. Yu, Y., Liu, F., Zhang, R. & Liu, J. Suspension 3D printing of liquid metal into self-healing hydrogel. Adv. Mater. Technol. 2, 1700173 (2017).

    Article  Google Scholar 

  33. Park, Y. G. et al. Three-dimensional, high-resolution printing of carbon nanotube/liquid metal composites with mechanical and electrical reinforcement. Nano Lett. 19, 4866–4872 (2019).

    Article  Google Scholar 

  34. Votzke, C., Daalkhaijav, U., Menguc, Y. & Johnston, M. L. 3D-printed liquid metal interconnects for stretchable electronics. IEEE Sens. J. 19, 3832–3840 (2019).

    Article  Google Scholar 

  35. Anderson, T. J. & Ansara, I. The Ga-In (gallium-indium) system. JPE 12, 64–72 (1991).

    Article  Google Scholar 

  36. Ren, L. et al. Nanodroplets for stretchable superconducting circuits. Adv. Funct. Mater. 26, 8111–8118 (2016).

    Article  Google Scholar 

  37. Tang, S. Y. et al. Phase separation in liquid metal nanoparticles. Matter 1, 192–204 (2019).

    Article  Google Scholar 

  38. Wu, Z. X., Zhang, Y. W. & Srolovitz, D. J. Dislocation-twin interaction mechanisms for ultrahigh strength and ductility in nanotwinned metals. Acta Mater. 57, 4508–4518 (2009).

    Article  Google Scholar 

  39. Zhang, Z. et al. Dislocation mechanisms and 3D twin architectures generate exceptional strength-ductility-toughness combination in CrCoNi medium-entropy alloy. Nat. Commun. 8, 14390 (2017).

    Article  Google Scholar 

  40. Matsukawa, Y. et al. The effect of crystallographic mismatch on the obstacle strength of second phase precipitate particles in dispersion strengthening: bcc Nb particles and nanometric Nb clusters embedded in hcp Zr. Acta Mater. 102, 323–332 (2016).

    Article  Google Scholar 

  41. Tang, S. et al. Precipitation strengthening in an ultralight magnesium alloy. Nat. Commun. 10, 1003 (2019).

    Article  Google Scholar 

  42. Malakooti, M. H. et al. Liquid metal supercooling for low‐temperature thermoelectric wearables. Adv. Funct. Mater. 29, 1906098 (2019).

    Article  Google Scholar 

  43. Bautista, R. G. Gallium metal recovery. J. Miner. Met. Mater. Soc. 41, 30–31 (1989).

    Article  Google Scholar 

  44. Jin, Y. et al. Materials tactile logic via innervated soft thermochromic elastomers. Nat. Commun. 10, 4187 (2019).

    Article  Google Scholar 

  45. Matsuzaki, R. & Tabayashi, K. Highly stretchable, global, and distributed local strain sensing line using GaInSn electrodes for wearable electronics. Adv. Funct. Mater. 25, 3806–3813 (2015).

    Article  Google Scholar 

  46. Guo, R. et al. Semiliquid metal enabled highly conductive wearable electronics for smart fabrics. ACS Appl. Mater. Interfaces 11, 30019–30027 (2019).

    Article  Google Scholar 

  47. Ma, B. et al. A versatile approach for direct patterning of liquid metal using magnetic field. Adv. Funct. Mater. 29, 1901370 (2019).

    Article  Google Scholar 

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

    Article  Google Scholar 

  49. Wu, Y.-H. et al. Liquid metal fiber composed of a tubular channel as a high-performance strain sensor. J. Mater. Chem. C 5, 12483–12491 (2017).

    Article  Google Scholar 

  50. Jeong, Y. R. et al. A skin-attachable, stretchable integrated system based on liquid GaInSn for wireless human motion monitoring with multi-site sensing capabilities. NPG Asia Mater. 9, e443 (2017).

    Article  Google Scholar 

  51. Gao, Q. et al. Microchannel structural design for a room-temperature liquid metal based super-stretchable sensor. Sci. Rep. 9, 5908 (2019).

    Article  Google Scholar 

  52. Feng, B. et al. Nacre‐inspired, liquid metal‐based ultrasensitive electronic skin by spatially regulated cracking strategy. Adv. Funct. Mater. 31, 2102359 (2021).

    Article  Google Scholar 

  53. Wang, X., Liu, Z. & Zhang, T. Flexible sensing electronics for wearable/attachable health monitoring. Small 13, 1602790 (2017).

    Article  Google Scholar 

  54. Wang, C. et al. Advanced carbon for flexible and wearable electronics. Adv. Mater. 31, 1801072 (2019).

    Article  Google Scholar 

  55. Liu, Z. et al. Surface strain redistribution on structured microfibers to enhance sensitivity of fiber-shaped stretchable strain sensors. Adv. Mater. 30, 1704229 (2018).

    Article  Google Scholar 

  56. Bartlett, M. D., Markvicka, E. J. & Majidi, C. Rapid fabrication of soft, multilayered electronics for wearable biomonitoring. Adv. Funct. Mater. 26, 8496–8504 (2016).

    Article  Google Scholar 

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Acknowledgements

G.L. and Z.L. acknowledge support from the National Key Research and Development Program of China (grant no. 2021YFF0501601), the National Natural Science Foundation of China (grant nos. 81927804 and U1913601) and NSFC-Shenzhen Robotics Basic Research Center Program (grant no. U2013207). X.M. recognizes funding from Shenzhen Science and Technology Program (grant no. KQTD20170809110344233), Shenzhen Bay Laboratory (grant no. SZBL201906281005) and the National Natural Science Foundation of China (grant no. 92163109). We thank L. Shi for guiding the circuit design of the flexible circuit board.

Author information

Authors and Affiliations

  1. Sauvage Laboratory for Smart Materials, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, China

    Guoqiang Li, Mingyang Zhang, Man Yuan, Junjie Wu & Xing Ma

  2. State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin, China

    Sanhu Liu & Zhiwu Xu

  3. Research Center for Neural Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China

    Mei Yu, Lijun Teng, Guanglin Li & Zhiyuan Liu

  4. Shenzhen Key Laboratory of Smart Sensing and Intelligent Systems, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China

    Mei Yu, Lijun Teng, Guanglin Li & Zhiyuan Liu

  5. School of Sensing Science and Engineering, Shanghai Jiaotong University, Shanghai, China

    Jinhong Guo

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Contributions

G.L. conceived the project, designed the experiments, prepared the 2D/3D structured sensors and analysed the data. M.Z. and S.L. characterized the microstructures of Ga–In alloys. M.Y. and J.W. prepared the 3D structured wearable sensor. L.T. designed and prepared the LED array. X.M. and Z.L. supervised this work. All the authors discussed and commented on the manuscript.

Corresponding authors

Correspondence to Zhiyuan Liu or Xing Ma.

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The authors declare no competing interests.

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Nature Electronics thanks the anonymous reviewers for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–27, Table 1, Notes 1–7 and references.

Supplementary Video 1

Preparation method of Ga–10In solid wire.

Supplementary Video 2

Bending experiment to compare the plasticity between Ga–10In and Ga–15In solid wire.

Supplementary Video 3

Dynamic processes of crystallizing and melting of Ga–10In solid wire.

Supplementary Video 4

Comparison of the stiffness between pure Ga and Ga–10In alloys.

Supplementary Video 5

Timing and sequence for turning the LED array on and off.

Supplementary Video 6

Fabrication process of 3D helical conductive structure using an automatic winding machine.

Supplementary Video 7

A 3D structured sensor for detecting finger movement and performing thermal therapy.

Supplementary Video 8

Wearable and wireless finger motion detection device.

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Li, G., Zhang, M., Liu, S. et al. Three-dimensional flexible electronics using solidified liquid metal with regulated plasticity. Nat Electron 6, 154–163 (2023). https://doi.org/10.1038/s41928-022-00914-8

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