Foremny Katharina, Konerding Wiebke S, Behrens Ailke, Baumhoff Peter, Froriep Ulrich P, Kral Andrej, Doll Theodor
Institute of AudioNeuroTechnology and Department of Experimental Otology, ENT Clinic, Hannover Medical School, 30625 Hannover, Germany.
Division of Translational Biomedical Engineering, Fraunhofer Institute for Toxicology and Experimental Medicine ITEM, 30625 Hannover, Germany.
Nanomaterials (Basel). 2021 Apr 17;11(4):1029. doi: 10.3390/nano11041029.
Current developments of electrodes for neural recordings address the need of biomedical research and applications for high spatial acuity in electrophysiological recordings. One approach is the usage of novel materials to overcome electrochemical constraints of state-of-the-art metal contacts. Promising materials are carbon nanotubes (CNTs), as they are well suited for neural interfacing. The CNTs increase the effective contact surface area to decrease high impedances while keeping minimal contact diameters. However, to prevent toxic dissolving of CNTs, an appropriate surface coating is required. In this study, we tested flexible surface electrocorticographic (ECoG) electrodes, coated with a CNT-silicone rubber composite. First, we describe the outcome of surface etching, which exposes the contact nanostructure while anchoring the CNTs. Subsequently, the ECoG electrodes were used for acute in vivo recordings of auditory evoked potentials from the guinea pig auditory cortex. Both the impedances and the signal-to-noise ratios of coated contacts were similar to uncoated gold contacts. This novel approach for a safe application of CNTs, embedded in a surface etched silicone rubber, showed promising results but did not lead to improvements during acute recordings.
用于神经记录的电极的当前发展满足了生物医学研究以及电生理记录中对高空间分辨率的应用需求。一种方法是使用新型材料来克服现有金属触点的电化学限制。有前景的材料是碳纳米管（CNT），因为它们非常适合神经接口。碳纳米管增加了有效接触表面积以降低高阻抗，同时保持最小的接触直径。然而，为了防止碳纳米管的有毒溶解，需要适当的表面涂层。在本研究中，我们测试了涂有碳纳米管 - 硅橡胶复合材料的柔性表面皮层脑电图（ECoG）电极。首先，我们描述了表面蚀刻的结果，其在固定碳纳米管的同时暴露了接触纳米结构。随后，将ECoG电极用于豚鼠听觉皮层听觉诱发电位的急性体内记录。涂覆触点的阻抗和信噪比均与未涂覆的金触点相似。这种将碳纳米管安全应用于表面蚀刻硅橡胶中的新方法显示出了有前景的结果，但在急性记录期间并未带来改善。
