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Nano Research 2021, 14(9): 3248-3252 https://doi.org/10.1007/s12274-021-3458-0
Research Article | Issue | Published: 15 April 2021

Fabric-substrated capacitive biopotential sensors enhanced by dielectric nanoparticles

Show Author's Information Xiangjun Chen1,§,  Xiaoxiang Gao2,§,  Akihiro Nomoto2,§,  Keren Shi1,  Muyang Lin2,  Hongjie Hu1,  Yue Gu1,  Yangzhi Zhu2,  Zhuohong Wu2,  Xue Chen1,  Xinyu Wang2,  Baiyan Qi1,  Sai Zhou1,  Hong Ding2,  Sheng Xu1,2,3,4( )
Materials Science and Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
Department of NanoEngineering, University of California San Diego, La Jolla, CA 92093, USA
Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA
Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA

§ Xiangjun Chen, Xiaoxiang Gao, and Akihiro Nomoto contributed equally to this work.

Keywords:
stretchable, signal-to-noise ratio (SNR), capacitive sensing, biopotential, calcium copper titanate (CCTO)
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Chen X, Gao X, Nomoto A, et al. Fabric-substrated capacitive biopotential sensors enhanced by dielectric nanoparticles. Nano Research, 2021, 14(9): 3248-3252. https://doi.org/10.1007/s12274-021-3458-0
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Abstract Full text Electronic supplementary material About this article

Wearable biopotential sensing devices are essential to long-term and real-time monitoring of human health. Non-contact, capacitive sensing electrodes prevent potential skin irritations, and are thus beneficial for long-term monitoring. Existing capacitive electrodes are either connected to a separate control circuit via external wires or have limited sensing capacitances, which leads to low signal qualities. This study demonstrates a stretchable capacitive sensing device with integrated electrodes and control electronics, with enhanced signal qualities. The electrodes and the control electronics are fabricated on a common fabric substrate for breathability and strain-limiting protection. The stretchable electrodes are based on an island-bridge design with a stretchability as high as ~ 100%, and an area ratio as high as ~ 80%. By using a dielectric calcium copper titanate (CCTO) composite as the adhesive layer, the electrode capacitance can be increased, yielding an enhanced signal-to-noise ratio (SNR) in the acquired biopotentials. This device offers a convenient and comfortable approach for long-term non-contact monitoring of biopotential signals.


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Electronic supplementary material
About this article

Fabric-substrated capacitive biopotential sensors enhanced by dielectric nanoparticles

Show Author's information Xiangjun Chen1,§, Xiaoxiang Gao2,§, Akihiro Nomoto2,§, Keren Shi1, Muyang Lin2, Hongjie Hu1, Yue Gu1, Yangzhi Zhu2, Zhuohong Wu2, Xue Chen1, Xinyu Wang2, Baiyan Qi1, Sai Zhou1, Hong Ding2, Sheng Xu1,2,3,4( )
Materials Science and Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
Department of NanoEngineering, University of California San Diego, La Jolla, CA 92093, USA
Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA
Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA

§ Xiangjun Chen, Xiaoxiang Gao, and Akihiro Nomoto contributed equally to this work.

Abstract

Wearable biopotential sensing devices are essential to long-term and real-time monitoring of human health. Non-contact, capacitive sensing electrodes prevent potential skin irritations, and are thus beneficial for long-term monitoring. Existing capacitive electrodes are either connected to a separate control circuit via external wires or have limited sensing capacitances, which leads to low signal qualities. This study demonstrates a stretchable capacitive sensing device with integrated electrodes and control electronics, with enhanced signal qualities. The electrodes and the control electronics are fabricated on a common fabric substrate for breathability and strain-limiting protection. The stretchable electrodes are based on an island-bridge design with a stretchability as high as ~ 100%, and an area ratio as high as ~ 80%. By using a dielectric calcium copper titanate (CCTO) composite as the adhesive layer, the electrode capacitance can be increased, yielding an enhanced signal-to-noise ratio (SNR) in the acquired biopotentials. This device offers a convenient and comfortable approach for long-term non-contact monitoring of biopotential signals.

Keywords: stretchable, signal-to-noise ratio (SNR), capacitive sensing, biopotential, calcium copper titanate (CCTO)

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Publication history
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Acknowledgements

Publication history

Received: 06 January 2021
Revised: 17 March 2021
Accepted: 21 March 2021
Published: 15 April 2021
Issue date: September 2021

Copyright

© Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature 2021

Acknowledgements

We thank Yutaka Imai and Yota Komoriya for their support to this project and S. Xiang for constructive feedback on the manuscript preparation. This material is based on research sponsored by Air Force Research Laboratory under agreement number FA8650-18-2-5402. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of Air Force Research Laboratory (AFRL) or the U.S. Government. All bio-experiments were conducted with the approval of the Institutional Review Board of the University of California, San Diego.

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