"Solving Problems with a Reverse Approach" KAIST Develops Customized 3D Brain Neural Chip

KAIST announced on September 25 that the research team led by Professor Nam Yoonki from the Department of Bio and Brain Engineering has developed a platform technology that enables the fabrication of "3D microelectrode chips" in various forms of customized in vitro culture chips.

(From left) Professor Nam Yoonki of Bio and Brain Engineering, Postdoctoral Researcher Yoon Dongjo. Provided by KAIST

Brain neural tissue cultured in vitro is widely used as a simplified experimental model for brain research. However, existing devices based on semiconductor processes have limitations in implementing morphological variations and three-dimensional (3D) structures. This is because the fabrication of 3D microelectrode chips has traditionally relied on semiconductor processes, which restrict design flexibility for three-dimensional structures and require high costs.

To overcome these challenges, 3D printing-based fabrication technologies have recently been proposed. However, the conventional sequence of "patterning conductive materials → applying insulators → electrode opening" still posed limitations in terms of design flexibility for various three-dimensional neural network structures for in vitro cultures.

The research team addressed these issues with a "reverse approach." By first creating hollow channel structures using a 3D printer, they allowed conductive ink to automatically fill the empty spaces through capillary action, forming electrodes and wiring. This resulted in the development of a "customized 3D brain neural chip."

In particular, by leveraging the excellent three-dimensional design flexibility offered by 3D printing technology and the ability to use printed structures as insulators, the team introduced a process that reverses the conventional fabrication sequence. This innovative method enables more flexible design and functional measurement of three-dimensional neural network models for in vitro cultures.

The new platform allows for the implementation of various chip forms, including probe-type, cube-type, and modular-type chips. It also supports the fabrication of electrodes using a range of materials such as graphite, conductive polymers, and silver nanoparticles.

This technology enables simultaneous measurement of multichannel neural signals generated both inside and outside three-dimensional neural networks, allowing for precise analysis of dynamic interactions and connectivity between neurons.

Professor Nam stated, "This study is significant because it expands the design freedom for neural chip fabrication by combining 3D printing and capillary action. This technology will contribute not only to fundamental brain science research using neural tissue, but also to the advancement of applications such as cell-based biosensors and bio-computing."

Meanwhile, Dr. Yoon Dongjo from the Department of Bio and Brain Engineering at KAIST participated as the first author of this study. The research results were recently published online in the international journal Advanced Functional Materials.

The "3D microelectrode chip" refers to a neural interface that can measure and stimulate the electrical activity of neurons through multiple microelectrodes arranged in three-dimensional space.

This content was produced with the assistance of AI translation services.