Alsadat Hejazi Maryam, Seyedi Seyed Amir, Mehdizadeh Alireza
Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
Research Center for Neuromodulation and Pain, Shiraz University of Medical Scineces, Shiraz, Iran.
J Biomed Phys Eng. 2023 Dec 1;13(6):573-576. doi: 10.31661/jbpe.v0i0.2306-1633. eCollection 2023 Dec.
Microelectrode Arrays (MEAs) neural interfaces are considered implantable devices that interact with the nervous system to monitor and/or modulate brain activity. Graphene-based materials are utilized to address some of the current challenges in neural interface design due to their desirable features, such as high conductance, large surface-to-volume ratio, suitable electrochemical properties, biocompatibility, flexibility, and ease of production. In the current study, we fabricated and characterized a type of flexible, ultrasmall, and implantable neurostimulator based on graphene fibers. In this procedure, wet-spinning was employed to create graphene fibers with diameters of 10 to 50 µm. A 10-channel polyimide Printed Circuit Board (PCB) was then custom-designed and manufactured. The fibers were attached to each channel by conductive glue and also insulated by soaking them in a polyurethane solution. The tips were subsequently exposed using a blowtorch. Microstructural information on the fibers was obtained using Scanning Electron Microscopy (SEM), and the measurements of Electrochemical Impedance Spectroscopy (EIS) were conducted for each electrode. Flexible MEAs were created using graphene fibers with diameters ranging from 10 to 50 microns with a spacing of 150 microns. This method leads to producing electrode arrays with any size of fibers and a variety of channel numbers. The flexible neural prostheses can replace conventional electrodes in both neuroscience and biomedical research.
微电极阵列（MEAs）神经接口被认为是可植入设备，可与神经系统相互作用以监测和/或调节大脑活动。基于石墨烯的材料因其具有诸如高电导率、大的表面积与体积比、合适的电化学性质、生物相容性、柔韧性以及易于生产等理想特性，被用于应对神经接口设计中的一些当前挑战。在本研究中，我们制造并表征了一种基于石墨烯纤维的柔性、超小型且可植入的神经刺激器。在此过程中，采用湿纺法制备直径为10至50微米的石墨烯纤维。然后定制设计并制造了一个10通道的聚酰亚胺印刷电路板（PCB）。通过导电胶将纤维附着到每个通道上，并将它们浸泡在聚氨酯溶液中进行绝缘处理。随后用喷灯将尖端暴露出来。使用扫描电子显微镜（SEM）获得纤维的微观结构信息，并对每个电极进行电化学阻抗谱（EIS）测量。使用直径范围为10至50微米、间距为150微米的石墨烯纤维创建了柔性微电极阵列。这种方法能够生产出具有任意纤维尺寸和各种通道数的电极阵列。柔性神经假体可在神经科学和生物医学研究中替代传统电极。
