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An electrically conductive silver–polyacrylamide–alginate hydrogel composite for soft electronics

A Publisher Correction to this article was published on 31 March 2021

This article has been updated

Abstract

Hydrogels offer tissue-like compliance, stretchability, fracture toughness, ionic conductivity and compatibility with biological tissues. However, their electrical conductivity (<100 S cm−1) is inadequate for digital circuits and applications in bioelectronics. Furthermore, efforts to increase conductivity by using hydrogel composites with conductive fillers have led to compromises in compliance and deformability. Here, we report a hydrogel composite that has a high electrical conductivity (>350 S cm−1) and is capable of delivering direct current while maintaining soft compliance (Young’s modulus < 10 kPa) and deformability. Micrometre-sized silver flakes are suspended in a polyacrylamide–alginate hydrogel matrix and, after going through a partial dehydration process, the flakes form percolating networks that are electrically conductive and robust to mechanical deformations. To illustrate the capabilities of our silver–hydrogel composite, we use the material in a stingray-inspired swimmer and a neuromuscular electrical stimulation electrode.

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Fig. 1: Soft, stretchable and electrically conductive hydrogel composite.
Fig. 2: Material characterization.
Fig. 3: Stingray-inspired soft swimmer.
Fig. 4: Neuromuscular electrical stimulation electrode.

Data availability

The data that support the plots within this paper and the other findings of this study are available from the corresponding author upon reasonable request.

Code availability

The customized tracking algorithm used in this work is available at https://doi.org/10.1184/R1/14039801.

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Acknowledgements

We acknowledge support from the NOPP Award (N000141812843; Research Collaborator R. Beach). We thank S. Kim for help with the FEA simulation of Joule heating using ANSYS software.

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Authors

Contributions

Y.O., C.P., M.J.F., X.H., J.L. and C.M. designed the research; Y.O. and C.P. fabricated the materials; Y.O., C.P. and M.J.F. performed the experiments; Y.O., C.P., M.J.F., J.L. and C.M. analysed the data; Y.O., C.P. and X.H. produced the demonstration of the soft stingray-inspired swimmer; Y.O., C.P. and J.L. demonstrated the neuromuscular electrical stimulation electrodes; Y.O., C.P., M.J.F., X.H., J.L. and C.M. wrote the manuscript. Y.O., C.P., M.J.F. and C.M. revised the manuscript.

Corresponding author

Correspondence to Carmel Majidi.

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The authors declare no competing interests.

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Peer review information Nature Electronics thanks Guo Zhan Lum, Shaoting Lin 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 Figs. 1–20, Discussions 1 and 2, and Table 1.

Reporting Summary

Supplementary Video 1

LED circuitry.

Supplementary Video 2

Stingray-inspired soft swimmer.

Supplementary Video 3

Neuromuscular electrical stimulation electrode on the tibialis anterior muscle of the leg.

Supplementary Video 4

Neuromuscular electrical stimulation electrode on the posterior muscle of the arm.

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Ohm, Y., Pan, C., Ford, M.J. et al. An electrically conductive silver–polyacrylamide–alginate hydrogel composite for soft electronics. Nat Electron 4, 185–192 (2021). https://doi.org/10.1038/s41928-021-00545-5

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