Engineering Electrodes with Robust Conducting Hydrogel Coating for Neural Recording and Modulation.

Area of Science:

• Bioelectronics
• Materials Science
• Biomedical Engineering

Background:

• Conducting polymers on metallic electrodes offer bioelectronic advantages like biocompatibility and conductivity.
• A major limitation is the fragile interface between conducting polymers and electrodes in physiological environments, hindering reliability.

Purpose of the Study:

• To establish a general and reliable strategy for interfacing conventional electrodes with conducting hydrogel coatings.
• To enhance the robustness, biocompatibility, and long-term reliability of bioelectronic interfaces.

Main Methods:

• Developing a conducting hydrogel coating with tissue-like modulus and desirable electrochemical properties.
• Utilizing numerical modeling to understand the toughening mechanisms, covalent polymer anchorage, and chemical cross-linking.
• In vivo implantation in freely-moving mouse models for testing stability during recording and stimulation.

Main Results:

• A robust interface between conducting hydrogel coatings and conventional electrodes was successfully established.
• Numerical modeling identified key mechanisms contributing to the interface's long-term robustness.
• Stable electrophysiological recordings and reliable low-voltage electrical stimulation were achieved in vivo over the long term.

Conclusions:

• The developed strategy significantly improves the long-term robustness and reliability of bioelectronic interfaces.
• This approach addresses critical challenges in functional bioelectrode engineering.
• It paves the way for advanced diagnostic brain-machine interfaces.