用于辅助柔性神经电极深度植入的槽形截面硅针的设计

Design of a Grooved Cross-Section Silicon Needle for Assisting Deep Implantation of Flexible Neural Probe

针对柔性神经电极的深度植入屈曲问题,设计一种槽形截面硅针作为辅助植入工具,为电极植入提供暂时刚度.为定量化评价辅助工具的综合性能,结合临界屈曲力和截面积,综合考虑力学性能及生物性能,提出辅助工具的性能评价指数.基于该评价指数研究槽形截面硅针的最佳槽深比及槽宽比,其中最佳槽深比为工艺要求内的极大值,最佳槽宽比随着硅针厚度的增大而增大;利用性能评价指数定量证明相对于传统的圆形截面和矩形截面硅针,槽形截面硅针具有明显的性能优势.槽形截面硅针的仿真设计有利于筛选出截面最佳参数组合,减少加工数量,降低实验成本.

Aimed at the buckling problem of deep implantation of flexible neural probe, a grooved cross-section silicon needle is designed as an auxiliary implant tool to provide temporary stiffness for probe implantation. In order to quantitatively evaluate the comprehensive performance of auxiliary tools, combining critical buckling force and cross-section area, and considering mechanical and biological properties, the performance evaluation index of auxiliary tools is proposed. Based on this evaluation index, the optimal groove depth ratio and groove width ratio of the grooved cross-section silicon needle are studied. The best groove depth ratio is the maximum value within the process requirements while the best groove width ratio increases with the thickness of the silicon needle. Moreover, the performance evaluation index is used to quantitatively prove that the grooved cross-section silicon needle has obvious performance advantages over the traditional circular and rectangular cross-section silicon needles. The simulation design of the grooved cross-section silicon needle is conducive to screening the best parameter combination of the cross-section, reducing the number of processing and the cost of experiments.