Carbon-Fiber Based Microelectrode Array Embedded with a Biodegradable Silk Support for In Vivo Neural Recording

Area of Science:

• Neuroscience
• Biomaterials Engineering
• Medical Devices

Background:

• Carbon fiber microelectrodes offer improved neural recording with less tissue damage compared to conventional electrodes.
• A key limitation is their short insertion depth due to low stiffness, hindering deep brain access.

Purpose of the Study:

• To develop a carbon fiber microelectrode array with enhanced mechanical support for deeper brain penetration.
• To evaluate the long-term performance and biocompatibility of these novel electrodes.

Main Methods:

• Fabrication of 4-channel carbon fiber microelectrode arrays with biodegradable silk fibroin supports.
• Implantation in rat hippocampi for 1-month evaluation of electrochemical impedance and recording capability.
• Comparative analysis with tungsten-supported electrodes and immunohistochemical assessment of glial responses.

Main Results:

• Silk-supported electrodes demonstrated initial impedance increase and decreased active electrode count, which recovered after 1 month.
• Electrode impedance returned to baseline, and over 70% of electrodes remained active after 1 month.
• Silk supports significantly reduced reactive glial responses compared to tungsten supports.

Conclusions:

• The silk-supported carbon fiber microelectrode array facilitates long-term in vivo neural recording from deep brain regions.
• This technology minimizes reactive tissue responses, enhancing chronic implantation viability.