Shin, So-Bin Nam, Kyeong-Taek Roh, Hyeonhee Shinyong Shim Son Yunseo Lee, Byung Chul Kim, Yong-Kweon Lee, Seung-Ki Im, Maesoon Park, Jae-Hyoung 2024-01-12T06:33:49Z 2024-01-12T06:33:49Z 2023-08-02 2023-10 0925-4005 https://pubs.kist.re.kr/handle/201004/79816 Microelectrode array (MEA) is one of the representative platforms for recording and stimulating neurons to explore their populational electrophysiological activities. Due to the layered structures of the nervous system, various three-dimensional (3D) MEAs have been used to reach specific target depths of neuronal tissues. But it is still difficult to monolithically fabricate various heights of microelectrodes, particularly with optical transparency. Here, we present a 3D MEA with different heights fabricated by multi-step silicon deep reactive ion etching. The microelectrodes were embedded in reflowed glass for high transparency which enables both neural tissue observation and optical stimulation. The heights of microelectrodes were well controlled by our fabrication processes and electrical connections were made with through glass vias (TGVs) to the bottom side for individual addressing. To confine electric stimulation in a small area, we used microelectrodes neighboring a stimulation electrode as local returns. The feasibility of the fabricated MEA was demonstrated by stimulating the mouse retina and successfully recording spikes of ganglion cells located near the stimulation site. Consistent with our COMSOL simulation, the ex vivo experimental results showed the stimulation current confinement was effective. Our study provides a new tool for 3D nervous systems and its fabrication method. English Elsevier BV Fabrication of a transparent array of penetrating 3D microelectrodes with two different heights for both neural stimulation and recording Article 10.1016/j.snb.2023.134184 1 Sensors and Actuators, B: Chemical, v.393, pp.1 - 13 Sensors and Actuators, B: Chemical 393 1 13 Y scie scopus 001059394900001 Chemistry, Analytical Electrochemistry Instruments & Instrumentation Chemistry Electrochemistry Instruments & Instrumentation Article RETINAL GANGLION-CELLS ACTIVATION RESPONSES SYSTEM SCALE MICROTIP ELECTRODE ARRAY Multi-electrode array Neural stimulation and recording Deep reactive ion etching Through glass via Retinal prosthesis Artificial vision