A Soft‐Fiber Bioelectronic Device with Axon‐Like Architecture Enables Reliable Neural Recording In Vivo under Vigorous Activities

• DOI: 10.1002/adma.202407874
• Publication Date: 2024-07-26T05:31:17Z
• Authors: Chengqiang Tang; Zhengqi Han; Ziwei Liu; Wenjun Li; Jiahao Shen; Kailin Zhang; Shuting Mai; Jinyan Li; Xiao Sun; Xingfei Chen; Hongjian Li; Liyuan Wang; Jiaheng Liang; Meng Liao; Jianyou Feng; Chuang Wang; Jiajia Wang; Lei Ye; Yiqing Yang; Songlin Xie; Xiang Shi; Kaiwen Zeng; Xuefeng Zhang; Xiangran Cheng; Kun Zhang; Yue Guo; Han Yang; Yifei Xu; Qi Tong; Hongbo Yu; Peining Chen; Huisheng Peng; Xuemei Sun
• Keywords: Neurons; 0301 basic medicine; 03 medical and health sciences; Polymers; Electric Conductivity; Animals; Axons

AbstractImplantable neural devices that record neurons in various states, including static states, light activities such as walking, and vigorous activities such as running, offer opportunities for understanding brain functions and dysfunctions. However, recording neurons under vigorous activities remains a long‐standing challenge because it leads to intense brain deformation. Thus, three key requirements are needed simultaneously for neural devices, that is, low modulus, low specific interfacial impedance, and high electrical conductivity, to realize stable device/brain interfaces and high‐quality transmission of neural signals. However, they always contradict each other in current material strategies. Here, a soft fiber neural device capable of stably tracking individual neurons in the deep brain of medium‐sized animals under vigorous activity is reported. Inspired by the axon architecture, this fiber neural device is constructed with a conductive gel fiber possessing a network‐in‐liquid structure using conjugated polymers and liquid matrices and then insulated with soft fluorine rubber. This strategy reconciles the contradictions and simultaneously confers the fiber neural device with low modulus (300 kPa), low specific impedance (579 kΩ µm2), and high electrical conductivity (32 700 S m−1) – ≈1–3 times higher than hydrogels. Stable single‐unit spike tracking in running cats, which promises new opportunities for neuroscience is demonstrated.