A Hybrid Strategy‐Based Ultra‐Narrow Stretchable Microelectrodes with Cell‐Level Resolution
Hanfei Li, Fei Han, Lulu Wang, Laixin Huang, Oluwarotimi Williams Samuel, Hang Zhao, Ruijie Xie, Ping Wang, Qiong Tian, Qingsong Li, Yang Zhao, Mei Yu, Jing Sun, Ruofan Yang, Xiaomeng Zhou, Fēi Li, Guanglin Li, Yi Lu, Peizhi Guo, Zhiyuan Liu
Abstract
Abstract 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.