基体粗糙度对神经电极聚苯胺涂层性能的影响

Substrate roughness affects the properties of PANI coatings for neural electrode

采用电化学粗糙法对铂电极基体表面进行粗糙化处理,研究基体粗糙度对沉积在电极表面的聚苯胺涂层的电化学特性和稳定性的影响.结果表明:采用电化学粗糙法能够显著增加电极的表面粗糙度,得到可控的粗糙化基体;随着粗糙系数(fR)的增加,粗糙化基体的双层电容近乎线性增长,当fR为424时基体的双层电容是光滑基体的77倍,聚苯胺(PANI)涂层在粗糙化基体表面的聚合速率也随之提高,涂层表面形态更为均匀、致密;提高基体粗糙度,PANI修饰电极的导电性能显著提升、界面阻抗降低,同时电极稳定性得到改善,粗糙化基体PANI修饰电极(fR为424)的电荷密度相比光滑基体提高了5.6倍、1kHz处的界面阻抗降低了1/2.与光滑基体表面的PANI涂层相比,粗糙化基体表面的样品更有利于神经电极的电记录和刺激.

Platinum（Pt）substrates were electrochemically roughened.The electrochemical properties and stability of the roughened platinum electrodes modified with polyaniline（PANI）coatings were evaluated.Results show that：the surface roughness factors（fR）of Pt substrates can be increased in a controlled manner.With the increase of fR,the roughened substrates show linear increasing double layer capacitance（Cdl）.The Cdl of the roughened substrate（fR=424）is 38.9 mF/cm^2,which is about 77 times greater than that of a smooth substrate.The polymerization rate of PANI coatings increases as the roughness factors increase.The morphology of PANI coatings on the roughened substrates exhibits more uniform and compact.The charge density of PANI coatings on the roughened substrate（fR=424）increases by about5.6-fold and the interfacial impedance reduces half at the biologically relevant frequency of 1kHz compared to that of PANI coatings on a smooth substrate.These results indicate the potential use of PANI coatings on the roughened substrates in neural recording and stimulation.