Fabrication of a transparent array of penetrating 3D microelectrodes with two different heights for both neural stimulation and recording

Fabrication of a transparent array of penetrating 3D microelectrodes with two different heights for both neural stimulation and recording

Citation

S.-B. Shin, K.-T. Nam, H. Roh, S. Shim, Y. Son, B.C. Lee, Y.-K. Kim, S.-K. Lee, M. Im, J.-H. Park, Fabrication of a transparent array of penetrating 3D microelectrodes with two different heights for both neural stimulation and recording, Sensors and Actuators: B. Chemical 393 (2023) 134184. https://doi.org/10.1016/j.snb.2023.134184 

Keywords

  • Microelectrode array (MEA)
  • Neural stimulation and recording
  • Deep reactive ion etching (DRIE)
  • Through glass via (TGV)
  • Retinal prosthesis
  • Artificial vision
  • Spatial confinement
  • Return electrodes

Brief

This article presents a novel method for fabricating a transparent 3D microelectrode array (MEA) with varying electrode heights for enhanced neural stimulation and recording. 

Summary

This 2023 article in Sensors and Actuators: B. Chemical, authored by So-Bin Shin et al., details the fabrication and testing of a transparent, three-dimensional microelectrode array (MEA) for neural stimulation and recording.

Here's a summary of the key aspects:

  • Purpose: The researchers aimed to create a MEA capable of both stimulating and recording from neurons at different depths within neural tissue. The transparency of the MEA allows for simultaneous optical observation and stimulation of the tissue.
  • Design and Fabrication: The MEA features microelectrodes of two different heights, allowing access to different layers of neural tissue. The taller electrodes are used for stimulation and local return, while the shorter ones are used for recording. The fabrication process involves multi-step deep reactive ion etching (DRIE), glass reflow for transparency, and through-glass vias (TGVs) for electrical connections.
  • Spatial Confinement: A key feature is the placement of return electrodes around each stimulation electrode to confine the electric current and enable more targeted stimulation. COMSOL simulations validated the effectiveness of this design in confining the stimulation current.
  • Experimental Validation: The MEA's functionality was tested using ex vivo mouse retina. The researchers successfully stimulated retinal ganglion cells (RGCs) and recorded their activity using the MEA. The results showed spatially confined activation of RGCs, confirming the effectiveness of the return electrodes.
  • Significance: This research offers a novel tool for investigating the electrophysiological functions of neural tissues in 3D. The transparent MEA with spatially confined stimulation capability holds promise for various applications, including retinal prosthetics and exploration of neural circuits.

The authors conclude that the developed 3D MEA with varying electrode heights can be a valuable tool for future research on neural tissues and their functions.

Origin: https://www.sciencedirect.com/science/article/pii/S0925400523008997

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