Mechanically-Compliant Bioelectronic Interfaces through Fatigue-Resistant Conducting Polymer Hydrogel Coating

Area of Science:

• Biomaterials Science
• Electrochemistry
• Bioelectronics Engineering

Background:

• Conducting polymer hydrogels offer compliant, conductive interfaces for metallic bioelectrodes.
• Current hydrogel coatings face challenges with fatigue, cracking, and delamination during electrical interfacing.
• Long-term viability of bioelectronic devices is limited by hydrogel coating degradation.

Purpose of the Study:

• To develop a robust and fatigue-resistant conducting polymer hydrogel coating for metallic bioelectrodes.
• To engineer nanocrystalline domains at the hydrogel-metal interface to improve coating adhesion and durability.
• To evaluate the performance of the enhanced hydrogel coating in cardiac pacing applications.

Main Methods:

• Engineering nanocrystalline domains at the interface between conducting polymer hydrogels and metallic substrates.
• Fabrication of fatigue-resistant hydrogel coatings on conventional metallic bioelectrodes.
• In-vitro and in-vivo testing of the hydrogel-coated bioelectrodes, including cardiac pacing experiments.

Main Results:

• Achieved a general and reliable approach for fatigue-resistant conducting polymer hydrogel coatings.
• Demonstrated reduced pacing threshold voltage in cardiac pacing using the engineered hydrogel coatings.
• Showcased enhanced long-term reliability of electrical stimulation due to improved coating durability.

Conclusions:

• The engineered nanocrystalline domains effectively prevent fatigue crack propagation and delamination.
• The robust, biocompatible hydrogel coating significantly improves cardiac pacing efficacy and device longevity.
• This approach offers a promising strategy for next-generation seamless bioelectronic interfaces.