Amorphous Silicon Carbide Platform for Next Generation Penetrating Neural Interface Designs
Amorphous Silicon Carbide Platform for Next Generation Penetrating Neural Interface Designs
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DOI：
10.3390/mi9100480
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发表时间：
2018-10-01
期刊：
影响因子：
3.4
通讯作者：
Cogan, Stuart F.
中科院分区：
文献类型：
--
作者：
Deku, Felix;Frewin, Christopher L.;Cogan, Stuart F.
到目前为止，由于生物和非生物机制的失败，持续和可靠地记录和刺激慢性植入条件下的神经活动的微电极阵列一直未能进入神经接口界。横向尺寸在10微米或以下的阵列被认为可以最大限度地减少炎症反应；然而，种植体厚度的减少也会降低杨氏模数较低的材料的屈曲阈值。虽然在植入过程中使用更坚硬、更厚的材料作为运输航天飞机可以克服这些问题，但使用航天飞机造成的严重损害可能会产生许多其他生物并发症。非晶态碳化硅(a-碳化硅)具有优异的电绝缘性能和较大的杨氏模数，可用于制造具有更高抗屈曲能力的超小型阵列。制作了含有8-16个临界厚度为4微米或6微米的单小腿的皮质内植入物样机，6微米厚的小腿可以在没有插入辅助的情况下穿透大鼠的皮质。介绍了在没有任何结构支撑的情况下植入SIROF涂层阵列的单单元记录。这项工作表明，a-SIC可以为穿透皮质组织的设备提供良好的机械平台，同时将临界厚度保持在10微米以下。
Microelectrode arrays that consistently and reliably record and stimulate neural activity under conditions of chronic implantation have so far eluded the neural interface community due to failures attributed to both biotic and abiotic mechanisms. Arrays with transverse dimensions of 10 mu m or below are thought to minimize the inflammatory response; however, the reduction of implant thickness also decreases buckling thresholds for materials with low Young's modulus. While these issues have been overcome using stiffer, thicker materials as transport shuttles during implantation, the acute damage from the use of shuttles may generate many other biotic complications. Amorphous silicon carbide (a-SiC) provides excellent electrical insulation and a large Young's modulus, allowing the fabrication of ultrasmall arrays with increased resistance to buckling. Prototype a-SiC intracortical implants were fabricated containing 8 - 16 single shanks which had critical thicknesses of either 4 mu m or 6 mu m. The 6 mu m thick a-SiC shanks could penetrate rat cortex without an insertion aid. Single unit recordings from SIROF-coated arrays implanted without any structural support are presented. This work demonstrates that a-SiC can provide an excellent mechanical platform for devices that penetrate cortical tissue while maintaining a critical thickness less than 10 mu m.