Otte Elisabeth, Cziumplik Valerian, Ruther Patrick, Paul Oliver
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:3388-3392. doi: 10.1109/EMBC44109.2020.9176523.
This paper reports on the customized thinning of neural probes based on silicon (Si) using deep reactive ion etching (DRIE) as a post-processing step. The reduced probe dimensions are expected to minimize local tissue trauma, while guaranteeing probe integrity during implantation. For DRIE, the probes are partially masked by a micromachined Si cover chip comprising tailored cavities enabling any desired thinned length l and probe thickness t by a proper choice of cover chip design and DRIE parameters, respectively. A broad variety of probe designs were realized with shank tip thicknesses ranging from 35 µm down to 2 µm. All probes could successfully be implanted into a brain tissue phantom, demonstrating a pronounced reduction in insertion force from 0.55 mN for unprocessed probes to 0.08 mN for 2-µm-thin shanks. When the dura mater was mimicked by a polyethylene (PE) membrane, forces were reduced from 28.9 mN to 16.6 mN for 15-µm-thin shanks.
本文报道了基于硅（Si）的神经探针定制化减薄，采用深反应离子刻蚀（DRIE）作为后处理步骤。减小的探针尺寸有望将局部组织创伤降至最低，同时在植入过程中保证探针的完整性。对于DRIE，探针由一个微加工的硅盖片部分覆盖，该盖片包含定制的腔，通过分别适当选择盖片设计和DRIE参数，可实现任何所需的减薄长度l和探针厚度t。实现了多种探针设计，柄尖厚度范围从35 µm到2 µm。所有探针都能成功植入脑组织模型，显示出插入力显著降低，从未处理探针的0.55 mN降至2 µm细柄的0.08 mN。当用聚乙烯（PE）膜模拟硬脑膜时，15 µm细柄的力从28.9 mN降至16.6 mN。
