A 3D flexible neural interface based on a microfluidic interconnection cable capable of chemical delivery

Area of Science:

• Neuroscience
• Biomedical Engineering
• Materials Science

Background:

• Growing demand for multifunctional neural interfaces to understand neurological diseases.
• Challenges in implantable devices due to tissue responses and integrating microfluidics with 3D structures.
• Limitations of current microneedle arrays in combining chemical delivery with neural recording.

Purpose of the Study:

• To develop a novel microfluidic neural interface with integrated chemical delivery and neural recording capabilities.
• To overcome fabrication challenges associated with integrating microfluidics into 3D microneedle arrays.
• To demonstrate the functionality of the developed device in vivo.

Main Methods:

• Fabrication of a microfluidic interconnection cable (µFIC).
• Integration of the µFIC with a flexible penetrating microelectrode array (FPMA) featuring 3D silicon microneedles.
• In vivo demonstration of chemical delivery (KCl injection) and simultaneous neural signal recording.

Main Results:

• Successful fabrication and integration of the microfluidic interconnection cable with the 3D microneedle array.
• Demonstrated precise chemical delivery through the microfluidic channels.
• Achieved simultaneous neural signal recording before and after chemical injection in vivo.
• Observed no acute tissue response issues in the short-term in vivo test.

Conclusions:

• The developed microfluidic neural interface successfully integrates chemical delivery with neural recording capabilities.
• This technology addresses limitations in current neural interfaces, particularly for 3D microneedle designs.
• The device shows significant potential for advancing neuroscience research by enabling targeted drug delivery and simultaneous electrophysiological monitoring.