Stable and low-resistance polydopamine methacrylamide-polyacrylamide hydrogel for brain-computer interface  

高稳定、低电阻聚多巴胺甲基丙烯酰胺-聚丙烯酰胺水凝胶及其在脑机接口中的应用

作　　者：Lanlan Liu Yafeng Liu Ruitao Tang Jun Ai Yinji Ma Ying Chen Xue Feng 刘兰兰;刘亚风;唐瑞涛;艾骏;马寅佶;陈颖;冯雪(Institute of Flexible Electronics Technology of THU,Zhejiang,Jiaxing Key Laboratory of Flexible Electronics based Intelligent Sensing and Advanced Manufacturing Technology,Jiaxing 314000,China;AML,Department of Engineering Mechanics,Centre for Flexible Electronics Technology,Tsinghua University,Beijing 100084,China;Qiantang Science and Technology Innovation Center,Hangzhou 310016,China;College of Aerospace Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]Institute of Flexible Electronics Technology of THU,Zhejiang,Jiaxing Key Laboratory of Flexible Electronics based Intelligent Sensing and Advanced Manufacturing Technology,Jiaxing 314000,China [2]AML,Department of Engineering Mechanics,Centre for Flexible Electronics Technology,Tsinghua University,Beijing 100084,China [3]Qiantang Science and Technology Innovation Center,Hangzhou 310016,China [4]College of Aerospace Engineering,Chongqing University,Chongqing 400044,China

出　　处：《Science China Materials》2022年第8期2298-2308,共11页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(U20A6001,11921002,and 11902292);Zhejiang Province Key Research and Development Project(2021C01183,2020C05004,and 2021C05007-4);the Natural Science Foundation of Zhejiang Province of China(LQ19E030003)。

摘　　要：Signal drift and performance instability of brain-computer interface devices induced by the interface failure between rigid metal electrodes and soft human skin hinder the precise data acquisition of electroencephalogram(EEG).Thus,it is desirable to achieve a robust interface for brain-computer interface devices.Here,a kind of polydopamine methacrylamide-polyacrylamide(PDMA-PAAM)hydrogel is developed.To improve the adhesion,dopamine is introduced into the polyacrylamide hydrogel,through the amino and catechol groups of dopamine in an organic-inorganic interface to build a covalent and non-covalent interaction.A strong attachment and an effective modulus transition system can be formed between the metal electrodes and human skin,so that the peeling force between the PDMAPAAM hydrogel and the porcine skin can reach 22 N m^(-1).In addition,the stable conductivity and long-term operating life of the PDMA-PAAM hydrogel for more than 60 days at room temperature are achieved by adding sodium chloride(NaCl)and glycerol,respectively.The PDMA-PAAM hydrogel membrane fabricated in this work is integrated onto a flexible Au electrode applied in a brain-computer interface.In comparison,the collected EEG signal intensity and waveform are consistent with that of the commercial counterparts.And obviously,the flexible electrode with PDMA-PAAM hydrogel membrane is demonstrated to enable a more stable and userfriendly interface.硬质金属电极与柔软人体皮肤之间的界面失效会导致脑机接口器件的信号漂移和性能不稳定,影响脑电信号的精确采集.本研究设计并制备了一种聚多巴胺甲基丙烯酰胺-聚丙烯酰胺(PDMA-PAAM)水凝胶.将多巴胺引入到聚丙烯酰胺水凝胶中,通过多巴胺的氨基与邻苯二酚基团在有机-无机界面上建立共价和非共价相互作用提高了界面粘结力.金属电极与人体皮肤之间形成了强附着和有效模量过渡体系,PDMA-PAAM水凝胶与猪皮之间的剥离力达到22 N m^(-1).此外,通过添加氯化钠和甘油,PDMA-PAAM水凝胶具有稳定的电导率和室温下60天以上的长期使用寿命.将本研究制备的PDMA-PAAM水凝胶集成在柔性金电极上用于脑机接口,采集到的脑电信号强度和波形与同类商用产品基本一致,且PDMA-PAAM水凝胶柔性电极具有更稳定的界面.

关 键 词：flexible electronics DOPAMINE HYDROGELS braincomputer interface ELECTROENCEPHALOGRAM 

分 类 号：TN911.7[电子电信—通信与信息系统] TQ427.26[电子电信—信息与通信工程]