Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering-IMTEK, University of Freiburg, Freiburg, Germany.
J Biomed Mater Res B Appl Biomater. 2010 Apr;93(1):266-74. doi: 10.1002/jbm.b.31584.
The applicability of parylene C as an encapsulation material for implanted neural prostheses was characterized and optimized. The adhesion of parylene C was tested on different substrate materials, which were commonly used in neural prostheses and the efficiency of different adhesion promotion methods was investigated. On Si(3)N(4), platinum, and on a first film of parylene C, a satisfactory adhesion was achieved with Silane A-174, which even withstood standard steam sterilization. The adhesion to gold and polyimide could not be improved sufficiently with the tested methods. Furthermore, tensile tests and measurements of the degree of crystallinity were performed on untreated, on steam sterilized, and on annealed parylene C layers to investigate the influence of thermal treatment. This led to more brittle and stiffer films due to an increase in the crystalline portion in the parylene layers. Finally, an electrochemical impedance spectroscopy was used to test if a parylene C layer was able to protect a metallic structure against corrosion on a Si(3)N(4) substrate. The results indicated that this could be only possible by treating the substrate with Silane A-174. To receive parylene C layers with a good encapsulation performance, it is important to consider the materials, which are used in the neural prosthesis, to find the best suited process parameters.
聚对二甲苯 C 作为植入式神经假体封装材料的适用性进行了特征描述和优化。测试了聚对二甲苯 C 在不同基底材料上的附着力，这些基底材料常用于神经假体，并研究了不同附着力促进方法的效率。在氮化硅（Si(3)N(4)）、铂和第一层高聚物 C 上，采用 Silane A-174 获得了令人满意的附着力，即使经过标准的蒸汽灭菌也能保持。但采用测试方法不能充分提高聚对二甲苯 C 对金和聚酰亚胺的附着力。此外，对未经处理、蒸汽灭菌和退火的聚对二甲苯 C 层进行了拉伸试验和结晶度测量，以研究热处理的影响。这导致聚对二甲苯 C 层更脆和更硬，因为结晶部分增加。最后，采用电化学阻抗谱测试了聚对二甲苯 C 层是否能够保护 Si(3)N(4)基底上的金属结构免受腐蚀。结果表明，只有通过用 Silane A-174 处理基底才能实现这一点。为了获得具有良好封装性能的聚对二甲苯 C 层，必须考虑神经假体中使用的材料，以找到最佳的工艺参数。
