A Hybrid Strategy‐Based Ultra‐Narrow Stretchable Microelectrodes with Cell‐Level Resolution

• Published in: Advanced functional materials Vol. 33; no. 29
• Main Authors: Li, Hanfei, Han, Fei, Wang, Lulu, Huang, Laixin, Samuel, Oluwarotimi Williams, Zhao, Hang, Xie, Ruijie, Wang, Ping, Tian, Qiong, Li, Qingsong, Zhao, Yang, Yu, Mei, Sun, Jing, Yang, Ruofan, Zhou, Xiaomeng, Li, Fei, Li, Guanglin, Lu, Yi, Guo, Peizhi, Liu, Zhiyuan
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.07.2023
• Subjects: Conducting polymers; Electrodes; electrophysiology; hybrid strategy; inorganic conductive materials; Materials science; Microelectrodes; Micrometers; Monitoring; Photolithography; Polymer gels; Stretchability; stretchable microelectrodes; ultra‐narrow microelectrodes
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202300859

Stretchable ultra‐narrow (e.g., 10 µm in width) microelectrodes are crucial for the electrophysiological monitoring of single cells providing the fundamental understanding to the working mechanism of neuro network or other electrically functional cells. Current fabrication strategies either focus on the preparation of normal stretchable electrodes with hundreds of micrometers or millimeters in width by using inorganic conductive materials or develop conductive organic polymer gel for ultra‐narrow electrodes which suffer from low stretchability and instability for long‐term implantation, therefore, it is still highly desirable to explore bio‐interfacial ultra‐narrow stretchable inorganic electrodes. Herein, a hybrid strategy is reported to prepare ultra‐narrow multi‐channel stretchable microelectrodes without using photolithography or laser‐assisting etching. A 10 µm × 10 µm monitoring window is fabricated with enhanced interfacial impedance by the special rough surface. The stretchability achieves to 120% for this 10 µm‐width stretchable electrode. Supported by these superior properties, it is demonstrated that the stretchable microelectrodes can detect electrophysiological signals of single cells in vitro and collect electrophysiological signals more precisely in vivo. The reported strategy will open up the accessible preparation of the fine‐size stretchable microelectrode. It will significantly improve the resolution of monitoring and stimulation of inorganic stretchable electrodes. A hybrid strategy without lithography technology is used to realize the preparation of micro size (10 µm) multi‐channel inorganic stretchable electrode array and ensure their excellent stretchability (>100%). The special rough surface of the microelectrode array enhances the interface impedance. The electrode array is used to record the cell electrophysiological signal.