A high-density carbon fiber neural recording array technology

Area of Science:

• Neuroscience
• Materials Science
• Biomedical Engineering

Background:

• Traditional microwire and Utah-style neural recording arrays cause adverse biological responses and performance degradation.
• Existing carbon fiber electrodes lack scalability for high-density applications.

Purpose of the Study:

• To develop a scalable, high-density, 2D carbon fiber neural recording array.
• To overcome the limitations of current neural recording technologies.

Main Methods:

• Fabrication of a 32-channel carbon fiber monofilament array using silicon microfabrication and microassembly.
• Utilizing an out-of-plane microassembly technique for fiber insertion into a silicon substrate.

Main Results:

• Achieved a 38-micron pitch, four times denser than 1D arrays, with 5-micron diameter fibers.
• Demonstrated successful in vivo recording in rat motor cortex, capturing 22 units on 20 channels.
• Carbon fiber electrodes showed greater lateral compliance and minimal cross-section compared to tungsten microwires.

Conclusions:

• This high-density array represents a significant advancement in neural recording technology.
• The fabrication technique is scalable for larger electrode counts and potential microelectronic integration.
• Carbon fiber arrays offer a promising solution for reducing neural inflammation and increasing information density in neural recording.