Abstract
Wearable and implantable devices require conductive, stretchable and biocompatible materials. However, obtaining composites that simultaneously fulfil these requirements is challenging due to a trade-off between conductivity and stretchability. Here, we report on Ag–Au nanocomposites composed of ultralong gold-coated silver nanowires in an elastomeric block-copolymer matrix. Owing to the high aspect ratio and percolation network of the Ag–Au nanowires, the nanocomposites exhibit an optimized conductivity of 41,850 S cm−1 (maximum of 72,600 S cm−1). Phase separation in the Ag–Au nanocomposite during the solvent-drying process generates a microstructure that yields an optimized stretchability of 266% (maximum of 840%). The thick gold sheath deposited on the silver nanowire surface prevents oxidation and silver ion leaching, making the composite biocompatible and highly conductive. Using the nanocomposite, we successfully fabricate wearable and implantable soft bioelectronic devices that can be conformally integrated with human skin and swine heart for continuous electrophysiological recording, and electrical and thermal stimulation.
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Acknowledgements
This work was supported by the Institute for Basic Science (grant numbers IBS-R006-D1 and IBS-R006-A1). The authors thank the staff of the National Center for Inter-university Research Facilities (NCIRF) and the Research Institute of Advanced Materials (RIAM) in Seoul National University. The authors also thank M. Josephson for material and intellectual support of the animal research.
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S.C., S.I.H., D.J., H.J.H., T.H. and D.-H.K. designed the experiments. S.C., S.I.H., D.J., C.L., M.L., H.J.H., T.H. and D.-H.K. performed experiments and analysis. S.C., S.I.H., D.J., H.J.H., C.L., S.B., O.K.P., C.M.T., S.Y.B., S.-W.L., K.P., P.M.K. and R.N. performed in vivo animal experiments and data analysis. S.I.H., S.-W.L. and K.P. performed in vitro experiments and analysis. J.W.Y., J.H.R. and W.B.L. performed computer simulations. S.C., S.I.H., D.J., H.J.H., S.B., T.H. and D.-H.K. wrote the paper.
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Supplementary figures 1–15, Supplementary References
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The heat rolling-pressed Ag–Au nanocomposite was stretched to 200%, 400% and 840%
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Choi, S., Han, S.I., Jung, D. et al. Highly conductive, stretchable and biocompatible Ag–Au core–sheath nanowire composite for wearable and implantable bioelectronics. Nature Nanotech 13, 1048–1056 (2018). https://doi.org/10.1038/s41565-018-0226-8
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DOI: https://doi.org/10.1038/s41565-018-0226-8
