Insertion of linear 8.4 μm diameter 16 channel carbon fiber electrode arrays for single unit recordings.
Insertion of linear 8.4 μm diameter 16 channel carbon fiber electrode arrays for single unit recordings.
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DOI：
10.1088/1741-2560/12/4/046009
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发表时间：
2015-08
影响因子：
4
通讯作者：
Chestek CA
中科院分区：
文献类型：
--
作者：
Patel PR;Na K;Zhang H;Kozai TD;Kotov NA;Yoon E;Chestek CA
用聚对二甲苯-c绝缘并用PEDOT：pTS功能化的单根碳纤维电极（d=8.4 μm）已被证明可记录单个单位活性，但用镊子手动植入这些器械可能很困难。如果不改进插入方法，通过制造碳纤维阵列来增加通道数将是不切实际的。在这项研究中，我们利用水溶性涂层和结构骨架，使我们能够创建，植入和记录从完全功能化的碳纤维阵列与~150 μm的间距。两种方法进行了测试的碳纤维阵列的插入。第一种方法使用PEG涂层，暂时硬化纤维，同时在头端留下一小部分暴露。小的暴露部分（500 μm - 1 mm）容易穿透大脑，从而无需用镊子处理每根光纤即可插入。第二种方法涉及制造硅支撑结构，其中单个柄间隔150 μm。每个柄都有一个小凹槽，里面有一根单独的碳纤维。我们的结果表明，PEG涂层允许在5只大鼠中长期植入碳纤维阵列，在植入后31天检测到单位活性。硅支撑结构在3次急性大鼠手术中记录了单个单元活动。在其中一个手术中，构建了一个具有3层硅支撑结构和碳纤维的堆叠装置，并显示出易于插入大脑中，并在选定部位上进行单元活动。从这些研究中，我们发现碳纤维的间距约为150 μm，很容易插入大脑。这大大增加了慢性神经探针的记录密度，并为具有最小瘢痕反应的更高密度设备铺平了道路。
Single carbon fiber electrodes (d=8.4 μm) insulated with parylene-c and functionalized with PEDOT:pTS have been shown to record single unit activity but manual implantation of these devices with forceps can be difficult. Without an improvement in the insertion method any increase in the channel count by fabricating carbon fiber arrays would be impractical. In this study, we utilize a water soluble coating and structural backbones that allow us to create, implant, and record from fully functionalized arrays of carbon fibers with ~150 μm pitch. Two approaches were tested for the insertion of carbon fiber arrays. The first method used a PEG coating that temporarily stiffened the fibers while leaving a small portion at the tip exposed. The small exposed portion (500 μm – 1 mm) readily penetrated the brain allowing for an insertion that did not require the handling of each fiber by forceps. The second method involved the fabrication of silicon support structures with individual shanks spaced 150 μm apart. Each shank consisted of a small groove that held an individual carbon fiber. Our results showed that the PEG coating allowed for the chronic implantation of carbon fiber arrays in 5 rats with unit activity detected at 31 days post-implant. The silicon support structures recorded single unit activity in 3 acute rat surgeries. In one of those surgeries a stacked device with 3 layers of silicon support structures and carbon fibers was built and shown to readily insert into the brain with unit activity on select sites. From these studies we have found that carbon fibers spaced at ~150 μm readily insert into the brain. This greatly increases the recording density of chronic neural probes and paves the way for even higher density devices that have a minimal scarring response.