Shanghai Jiaotong University
目的 对带有涂层修饰的柔性神经电极进行力学综合性能的评估,为电极及涂层参数的优化设计提供依据。方法 对接触阶段、植入阶段以及微动阶段3个过程建立简化力学模型,以聚酰亚胺为电极材料,PEG为涂层材料,PDMS模具注塑法为涂层涂覆方法,设置40、80、120、160、200 μm的涂层厚度梯度,对临界载荷、最大形变量、脑组织最大应变3个因素进行综合对比评估。结果 厚度的增加会引起临界载荷的增大、最大形变量的减小以及脑组织最大应变的减小,同时也会导致脑组织应变区域增大。均衡3个因素考虑,选择200 μm作为涂层最佳厚度,在该厚度下,临界载荷为0.017 9 N,最大形变为0.010 1 mm,脑组织最大应变为0.011 4。结论 涂层厚度对神经电极的力学性能有较大影响,在具体情况下可通过设置多个力学性能因素的影响因子选择最优参数。涂层的最优参数选择可提高电极的性能，对神经电极的临床应用有着重要意义。
Objective Evaluate the mechanical comprehensive performance of the flexible neural electrode with coating modification, which will provide a basis for the optimal design of the electrode and coating parameters. Methods Simplified mechanical models were established for the three processes of contact phase, implantation phase and micromotion phase. The electrode material was polyimide, the coating material was PEG, and PDMS mold injection method was selected as coating method. The coating thickness gradients of 40, 80, 120, 160 and 200 μm were set, and the three factors of buckling force, maximum total deformation and maximum strain of brain tissue were comprehensively evaluated. Results As the thickness increases, the buckling force increases, the maximum total deformation and the maximum strain of the brain tissue decrease, but at the same time, the strain area of the brain tissue increases. For the consideration of three factors of equilibrium, 200 μm is chosen as the optimum thickness of the coating. At this thickness, the buckling force is 0.017 9 N, the maximum total deformation is 0.010 1 mm, and the maximum strain of brain tissue is 0.011 4. Conclusions The thickness of the coating has a great influence on the mechanical properties of the neural electrode. The optimal parameters can be selected by setting the influence factors of the mechanical performance factors under specific case.The optimal parameter selection of coating can improve the performance of electrode, which is of great significance for the clinical application of neural electrode.