IEEE Trans Nanobioscience. 2019 Apr;18(2):220-225. doi: 10.1109/TNB.2019.2905468. Epub 2019 Mar 15.
Glial encapsulation of chronically implanted neural probes inhibits recording and stimulation, and this signal loss is a significant factor limiting the clinical viability of most neural implant topologies for decades-long implantation. We demonstrate a mechanical proof of concept for silicon shank-style neural probes intended to minimize gliosis near the recording sites. Compliant whiskers on the edges of the probe fold inward to minimize tissue damage during insertion. Once implanted to the target depth and retracted slightly, these whiskers splay outward. The splayed tips, on which recording sites could be patterned, extend beyond the typical 50-100 [Formula: see text] radius of a glial scar. The whiskers are micrometer-scale to minimize or avoid glial scarring. Electrically inactive devices with whiskers of varying widths and curvature were designed and monolithically fabricated from a 5- [Formula: see text] silicon-on-insulator (SOI) wafer, and their mechanical functionality was demonstrated in a 0.6% agar brain phantom. Deflection was plotted versus deflection speed, and those that were most compliant actuated successfully. This probe requires no preparation for use beyond what is typical for a shank-style silicon probe.
胶质细胞对慢性植入的神经探针的包封抑制了记录和刺激,这种信号损失是限制大多数神经植入拓扑结构在长达数十年的植入过程中临床可行性的一个重要因素。我们展示了一种硅针状式神经探针的机械概念验证,旨在最大限度地减少记录部位附近的神经胶质增生。探针边缘上的弹性胡须向内折叠,以在插入过程中最小化组织损伤。一旦植入到目标深度并稍微缩回,这些胡须就会向外张开。可以在张开的尖端上(记录位点可以在其上进行图案化),超出了典型的 50-100μm 胶质瘢痕半径。这些胡须的尺寸为微米级,以最小化或避免胶质瘢痕形成。设计并采用具有不同宽度和曲率的胡须的电非活性器件,并从 5-μm 硅-绝缘体(SOI)晶片上进行整体制造,并在 0.6%琼脂脑模型中对其机械功能进行了演示。绘制了挠度与挠度速度的关系图,那些最柔顺的器件成功地进行了驱动。与通常的硅针式探针相比,这种探针在使用前不需要进行任何特殊准备。