The design, fabrication, and testing of a microelectrode array for chronic in vivo stimulation of the rat retina is presented. Epiretinal positioning of the array introduced design challenges associated with the surgical implantation approach into the rat ocular orbit. These anatomical and surgical challenges were overcome using microfabrication of thin-film Parylene C and platinum to create the array followed by thermal post-processing steps to achieve the required array geometry. An electroplated platinum-iridium coating was employed to increase the electrode charge storage capacity and then verified in benchtop electrochemical characterization. Preliminary in vivo implantations with sham devices containing no metal revealed chronic biocompatibility (up to 6 weeks) and acute trials with functional arrays illustrated device robustness against surgical trauma. This work represents the first epiretinal implant development for the rat animal model via a suitable soft neural interface device enabled through polymer MEMS micromachining.

中文翻译：

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一种用于大鼠视网膜慢性体内视网膜前刺激的植入式微电极阵列

介绍了用于大鼠视网膜慢性体内刺激的微电极阵列的设计、制造和测试。阵列的视网膜前定位引入了与手术植入方法相关的设计挑战到大鼠眼眶。使用薄膜 Parylene C 和铂的微细加工来创建阵列，然后进行热后处理步骤以实现所需的阵列几何形状，从而克服了这些解剖学和外科手术方面的挑战。采用电镀铂铱涂层来增加电极电荷存储容量，然后在台式电化学表征中进行验证。使用不含金属的假设备进行的初步体内植入显示出慢性生物相容性（长达 6 周），功能阵列的急性试验表明设备对手术创伤的鲁棒性。这项工作代表了通过聚合物 MEMS 微加工实现的合适的软神经接口设备为大鼠动物模型开发的第一个视网膜前植入物。