Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Barcelona, Spain.
Institut de Microelectrònica de Barcelona, IMB-CNM (CSIC), Campus UAB, Bellaterra, Spain.
Nat Nanotechnol. 2024 Apr;19(4):514-523. doi: 10.1038/s41565-023-01570-5. Epub 2024 Jan 11.
One of the critical factors determining the performance of neural interfaces is the electrode material used to establish electrical communication with the neural tissue, which needs to meet strict electrical, electrochemical, mechanical, biological and microfabrication compatibility requirements. This work presents a nanoporous graphene-based thin-film technology and its engineering to form flexible neural interfaces. The developed technology allows the fabrication of small microelectrodes (25 µm diameter) while achieving low impedance (∼25 kΩ) and high charge injection (3-5 mC cm). In vivo brain recording performance assessed in rodents reveals high-fidelity recordings (signal-to-noise ratio >10 dB for local field potentials), while stimulation performance assessed with an intrafascicular implant demonstrates low current thresholds (<100 µA) and high selectivity (>0.8) for activating subsets of axons within the rat sciatic nerve innervating tibialis anterior and plantar interosseous muscles. Furthermore, the tissue biocompatibility of the devices was validated by chronic epicortical (12 week) and intraneural (8 week) implantation. This work describes a graphene-based thin-film microelectrode technology and demonstrates its potential for high-precision and high-resolution neural interfacing.
影响神经接口性能的一个关键因素是用于与神经组织建立电通信的电极材料，该材料需要满足严格的电气、电化学、机械、生物和微制造兼容性要求。本工作提出了一种基于多孔石墨烯的薄膜技术及其工程，用于形成柔性神经接口。所开发的技术允许制造小的微电极（25 µm 直径），同时实现低阻抗（约 25 kΩ）和高电荷注入（3-5 mC cm）。在啮齿动物中进行的体内大脑记录性能评估显示出高保真记录（局部场电位的信噪比 >10 dB），而使用神经内植入物评估的刺激性能表明，对于激活大鼠支配胫骨前肌和足底骨间肌的坐骨神经内的轴突亚群，电流阈值低（<100 µA）且选择性高（>0.8）。此外，通过慢性皮层下（12 周）和神经内（8 周）植入物验证了器件的组织生物相容性。本工作描述了一种基于石墨烯的薄膜微电极技术，并展示了其在高精度和高分辨率神经接口中的潜力。
