Abstract
The development of durable and reliable bioelectrodes for high-quality bioelectrical signals acquisition has become a crucial technology in the field of human physiological condition monitoring and human-machine interfaces. However, most existing bioelectrodes are limited to conventional elastomeric substrates that suffer from mechanical mismatch and low permeability, and lack multifaceted attributes and essential synergistic properties akin to those found in biological skins. In this work, we report advanced substrate-free ultra-thin epidermal bioelectrodes (ASU-EBEs) based on free-standing conductive all-polymer (FCAP) films, which integrate the advantages of ultra-conformality, excellent stretchability and breathability into a single device. The resulting ASU-EBEs exhibit excellent conductivity of ∼475 S cm−1, outstanding stretchability of ∼48%, ultra-conformality to the interface of biological tissues and superior breathability. The enhanced electronic and mechanical performance is attributed to the introduction of water-soluble polyethylene oxide into poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT:PSS) to control the molecular π-π stacking distance and promote the formation of nanofiber structures. Hence, ASU-EBEs show much lower skin-contact impedance than the standard gel electrodes, enabling the use for long-term healthcare monitoring in complex daily conditions.
摘要
开发耐用且可靠的生物电极, 用以采集高质量的生物电信号, 已成为人体生理状态监测和人机交互领域的关键技术. 然而, 现有的生物电极多基于传统弹性基底, 这导致了机械性能不匹配和低渗透性等问题, 并且缺乏与生物皮肤类似的多方面属性和必要的协同特性. 本研究中, 我们报道了一种新型的基于自支撑导电全聚合物薄膜的超薄表皮生物电极(ASU-EBE). 该电极将超一致性、优异的拉伸性和透气性集成于一体, 展现了约475 S cm−1的高导电性, 约48%的出色拉伸性, 与生物组织界面的超一致性以及优异的透气性. 该电极的电子和机械性能得到提升, 这归功于在PEDOT:PSS中引入水溶性聚氧化乙烯, 以调节分子间π-π堆积距离, 并促进纳米纤维结构的形成. 因此, ASU-EBE在与皮肤接触时的阻抗远低于标准凝胶电极, 使其成为复杂日常环境下长期医疗监测的理想选择.
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Acknowledgements
This work was supported by the National Key Research and Development Program of China (2023YFB3608904), the National Natural Science Foundation of China (21835003 and 61704077), the Natural Science Foundation of Jiangsu Province (BE2019120 and BK20191374), the Foundation of Key Laboratory of Flexible Electronics of Zhejiang Province (2023FE002), the Natural Science Foundation of Jiangsu Higher Education Institutions of China (18KJB150025), the Program for Jiangsu Specially-Appointed Professor (RK030STP15001), the Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX21_0778, SJCX21_0298), the NUPT Scientific Foundation (NY219021 and NY219109), the Leading Talent of Technological Innovation of National Ten-Thousands Talents Program of China, and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).
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Author contributions Niu J and Lai WY conceived the idea; Li G carried out the material synthesis and performed the material characterization; Fang S, Gong Y, Shao R, and You T contributed to the electrophysiological measurement and design of human-machine interaction programs; Li G, Gong Y, Niu J, and Lai WY co-wrote the paper. All authors discussed the results and commented on the manuscript.
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Guanjun Li is a PhD candidate at Nanjing Post and Communications University. His research focuses on the development of high-performance electronic skins and epidermal electronics, including adhesive bioelectronic materials and devices, new conductive hydrogels, and biological tissue-electrode interface sensing technology.
Jian Niu is an associate professor at Nanjing University of Posts and Telecommunications. He received his PhD in physics from Lanzhou University in 2011. His research primarily focuses on the development and application of flexible and stretchable electronic devices.
Wen-Yong Lai is a full professor at Nanjing University of Posts and Telecommunications. He received his PhD degree from Fudan University in 2007. He then joined the Key Laboratory for Organic Electronics & Information Displays, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications. His research mainly focuses on the design, synthesis, and application of organic & polymer optoelectronic materials for organic/flexible electronics. He is also interested in the exploration of novel materials and processes for printed electronics.
Supplementary information Experimental details and supporting data are available in the online version of the paper.
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Substrate-Free Ultra-Thin Epidermal Bioelectrodes with Enhanced Conformality and Breathability for Long-Term Physiological Monitoring
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Li, G., Gong, Y., Fang, S. et al. Substrate-free ultra-thin epidermal bioelectrodes with enhanced conformality and breathability for long-term physiological monitoring. Sci. China Mater. 67, 1481–1490 (2024). https://doi.org/10.1007/s40843-024-2823-9
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DOI: https://doi.org/10.1007/s40843-024-2823-9