# Recent Advances in Microelectrode Array Interfaces for Organoids

## TL;DR

This paper reviews recent developments in 3D microelectrode arrays for studying brain organoids, aiming to better understand and treat neurological disorders.

## Contribution

The paper introduces advances in 3D MEA technologies that overcome limitations of traditional 2D MEAs in capturing 3D neural activity in organoids.

## Key findings

- Photolithography-based fabrication improves MEA flexibility and signal quality.
- Integration with perfusion systems enables long-term monitoring of organoid neural activity.
- 3D MEAs allow more comprehensive analysis of complex neural networks in organoids.

## Abstract

Electrophysiological studies using brain organoids provide valuable insights into neurological disorders and offer promising opportunities for therapeutic development. Accordingly, conventional two-dimensional microelectrode arrays (MEAs) are commonly employed to record neural activity with high spatiotemporal resolution. However, their measurements are mainly limited to the basal surface of the tissue. This limitation restricts the comprehensive analysis of the complex three-dimensional (3D) neural networks formed within organoids. To bridge this gap, this review summarizes recent advances in 3D MEA technologies, with a focus on device geometries, electrode designs, and neural signal acquisition strategies ranging from noninvasive to invasive approaches. Among these advances, photolithography-based fabrication processes have enabled submicron-scale structures, improving device flexibility, spatial resolution, and signal-to-noise ratio. Furthermore, the integration of 3D MEAs with perfusion systems and shape-transformable architectures facilitates stable, long-term electrophysiological monitoring of organoids. Finally, this review discusses emerging research trends and future perspectives in 3D MEA development in organoid-based neuroscience.