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Abstract：
This paper demonstrates, for the first time, the stability of synthetic diamond as a passive layer within neural implants. Leveraging the exceptional biocompatibility of intrinsic nanocrystalline diamond, a comprehensive review of material aging analysis in the context of in-vivo implants is provided. This work is based on electric impedance monitoring through the formulation of an analytical model that scrutinizes essential parameters such as the deposited metal resistivity, insulation between conductors, changes in electrode geometry, and leakage currents. The evolution of these parameters takes place over an equivalent period of approximately 10 years. The analytical model, focusing on a fractional capacitor, provides nuanced insights into the surface conductivity variation. A comparative study is performed between a classical polymer material (SU8) and synthetic diamond. Samples subjected to dynamic impedance analysis reveal distinctive patterns over time, characterized by their physical degradation. The results highlight the very high stability of diamond, suggesting promise for the electrode\'s enduring viability. To support this analysis, microscopic and optical measurements conclude the paper and confirm the high stability of diamond and its strong potential as a material for neural implants with long-life use.
摘要：
本文论证了,第一次,合成金刚石作为神经植入物中钝化层的稳定性。利用固有纳米晶金刚石的特殊生物相容性，提供了在体内植入物背景下的材料老化分析的全面审查。这项工作是基于电阻抗监测，通过制定一个分析模型，仔细检查基本参数，如沉积金属电阻率，导体之间的绝缘，电极几何形状的变化，和漏电流。这些参数的演变发生在大约10年的等效时期内。分析模型，专注于分数电容，提供了对表面电导率变化的细致入微的见解。在经典聚合物材料(SU8)和合成金刚石之间进行比较研究。经过动态阻抗分析的样品随着时间的推移显示出独特的模式，以它们的物理退化为特征。结果突出了钻石的非常高的稳定性，为电极的持久生存能力提供了希望。为了支持这一分析，微观和光学测量得出的结论是，本文证实了金刚石的高稳定性及其作为长寿命神经植入物材料的强大潜力。
