基于PDMS的人工视网膜神经微电极阵列

PDMS-Based Neural Microelectrode Arrays for Retinal Prosthesis

为了利用柔顺性材料实现电极位点与靶细胞的良好接触,同时保证微电极的可靠性,提出了一种新的聚二甲基硅氧烷(PDMS)微电极制作方法.该方法通过在硅基表面沉积金属层、光刻图形化以及电镀形成电极基本结构,然后通过PDMS浇注、湿法刻蚀、释放以及键合完成基于PDMS微电极制作.其中,微电极绝缘层制作和电极位点暴露采用浇注PDMS并结合外力夹压固化和PDMS湿法刻蚀来实现.使用该方法制作的PDMS电极,结构稳定、可靠性好,具有良好的贴附性.同时,通过SEM和阻抗测试对所制作的微电极进行了表面形貌和电学性能的测试和评价.结果显示,相对于传统方法制作的PDMS微电极,电化学阻抗降低了近60%(频率1 kHz处),基于该方法制作的PDMS微电极在力学和电学性能方面均具明显优势.

In order to improve the contact between electrode sites and target neurons by using conformable substrates,and meanwhile ensure the reliability of the microelectrode arrays,a new method for fabricating crack-free polydimethylsiloxane（PDMS）-based microelectrode arrays（MEAs） was presented.The device is constructed by depositing,patterning and electroplating gold to form wires and electrode sites on silicon wafer,and then embedding the wires in PDMS,exposing the electrode sites and bonding the second PDMS layer for bottom insulation.The embedding and exposing process involves pouring PDMS on the electroplated metal microstructures,curing with clamping and wet etching PDMS residues.In this way reliable and robust conformable MEAs were achieved.Prototype MEAs were also tested and evaluated by SEM and impedance test.The experimental results show,compared with conventional PDMS-based MEAs,the electro-chemical impedance decreases by 60%.The PDMS-based MEAs fabricated by the method proposed in this paper exhibite obvious advantages in mechanical and electrical properties.