Metallic Microneedle Electrode Array (m-MNEA) as a Novel Intracortical Neural Interface

This paper reports a novel intracortical neural interface based on metallic microneedle electrode array (m-MNEA). Compared to the silicon-based Utah Electrode Array (UEA), the gold standard for intracortical microelectrode, the m-MNEA has a similar microsize but overcomes the inherent limitations on mechanical strength and manufacturing difficulty, ensuring the biosafety and controlling the cost. Inspired by the acupuncture technique of traditional Chinese medicine, combining the microfabrication, advanced machining and electronic technology, 32-channel awn-shaped m-MNEA with 100 μm base diameter, 400 μm pitch and 2 mm length are realized. The fabrication process of m-MNEA is lithography-free and employs no complex wet etching. Owing to the PEDOT:PSS modification at the microelectrode tips, the electrical characteristics are greatly enhanced, performing good abilities of neural interaction.