MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, National and Local Joint Engineering Laboratory for Synthesis, Transformation and Separation of Extreme Environmental Nutrients, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150090, P. R. China.
Biomedical Microdevices Research Laboratory, Shenzhen Institutes of Advanced Technology, The Chinese Academy of Sciences, Shenzhen, 518055, P. R. China.
Adv Healthc Mater. 2023 Jul;12(18):e2203344. doi: 10.1002/adhm.202203344. Epub 2023 Apr 10.
Flexible electrode array, a new-generation neural microelectrode, is a crucial tool for information exchange between living tissues and external electronics. Till date, advances in flexible neural microelectrodes are limited because of their high impedance and poor mechanical consistency at tissue interfaces. Herein, a highly sensitive and omnidirectionally stretchable polymeric electrode array (PEA) is introduced. Micropyramid-nanowire composite structures are constructed to increase the effective surface area of PEA, achieving an exponential reduction in impedance compared with gold (Au) and flat polypyrrole electrodes. Moreover, for the first time, a suspended umbrella structure to enable PEA with omnidirectional stretchability of up to ≈20% is designed. The PEA can withstand 1000 cycles of mechanical loads without decrease in performance. As a proof of concept, PEA is conformally attached to a rat heart and tibialis anterior muscle, and electrophysiological signals (electrocardiogram and electromyogram) of the rat are successfully recorded. This strategy provides a new perspective toward highly sensitive and omnidirectionally stretchable PEA that can facilitate the practical application of neural electrodes.
柔性电极阵列，新一代神经微电极，是活体组织与外部电子设备之间信息交换的关键工具。迄今为止，由于其在组织界面处的高阻抗和较差的机械一致性，柔性神经微电极的进展受到限制。在此，引入了一种高灵敏度和全方位可拉伸的聚合物电极阵列 (PEA)。构建了微金字塔-纳米线复合结构来增加 PEA 的有效表面积，与金 (Au) 和平面聚吡咯电极相比，阻抗呈指数级降低。此外，首次设计了一种悬空伞状结构，使 PEA 具有高达 ≈20%的全方位可拉伸性。PEA 可以承受 1000 次机械负载循环而不会降低性能。作为概念验证，PEA 贴合在大鼠心脏和胫骨前肌上，并成功记录了大鼠的电生理信号（心电图和肌电图）。该策略为高灵敏度和全方位可拉伸 PEA 提供了新视角，这将有助于神经电极的实际应用。
