de Haro C, Mas R, Abadal G, Muñoz J, Perez-Murano F, Dominguez C
Department of Electronic Engineering, University Autonomous of Barcelona, Bellaterra, Spain.
Biomaterials. 2002 Dec;23(23):4515-21. doi: 10.1016/s0142-9612(02)00195-3.
The formation and properties of electrochemical platinum films grown on platinum contacts contained in implantable flexible microelectrodes were investigated. The resulting platinum deposits were obtained by applying cyclic voltammetry to baths containing concentrations around 70 mM of chloroplatinic acid. A pre-activation step was necessary before the platinum-electroplating step in order to achieve good adhesive properties. The benefits of this process were ascribed to higher corrosion resistance, lower impedance and improved adhesion to the sputtered platinum. These improvements can make the application of this electrochemical technique highly useful for increasing the lifetime of implantable microelectrode arrays, such as cuff structures (IEEE Trans. Biomed. Eng. 40 (1993) 640). These medical devices, obtained by semiconductor technology could be used for selective stimulation of nerve fascicles, although, poor long-term performance has been achieved with them. The dissolution rate for platinum thin-film microelectrodes under fixed corrosion test conditions was 38.8 ng/C. Lower rates were observed for electroplated microelectrodes, obtaining a dissolution rate of 7.8 ng/C under analogous experimental ageing conditions. The corrosion behaviour of the electroplated platinum during stimulation experimental conditions was estimated by electrochemical impedance spectroscopy.
研究了在可植入柔性微电极中所含铂触点上生长的电化学铂膜的形成和特性。通过对含有约70 mM氯铂酸浓度的镀液施加循环伏安法来获得所得的铂沉积物。在铂电镀步骤之前需要一个预活化步骤，以实现良好的粘附性能。该工艺的优点归因于更高的耐腐蚀性、更低的阻抗以及对溅射铂的粘附性提高。这些改进可以使这种电化学技术的应用对于延长可植入微电极阵列（如袖带结构，《IEEE生物医学工程汇刊》40 (1993) 640）的使用寿命非常有用。这些通过半导体技术获得的医疗设备可用于选择性刺激神经束，尽管它们的长期性能较差。在固定腐蚀测试条件下，铂薄膜微电极的溶解速率为38.8 ng/C。在类似的实验老化条件下，电镀微电极的溶解速率较低，为7.8 ng/C。通过电化学阻抗谱估计了电镀铂在刺激实验条件下的腐蚀行为。
