Advanced Metallic and Polymeric Coatings for Neural Interfacing: Structures, Properties and Tissue Responses

Area of Science:

• Biomaterials Science
• Neuroscience
• Materials Engineering

Background:

• Neural electrodes are crucial for brain-electronic interfaces, neuroprosthetics, and neuroregeneration.
• Current electrodes face challenges like foreign body responses, low sensitivity, and limited functionality.
• Surface coatings offer a practical and economical approach to enhance existing neural electrode performance.

Purpose of the Study:

• To categorize and analyze recent advancements in surface coatings for neural electrodes.
• To provide insights into material selection, functional design, and structural configuration for next-generation coatings.
• To highlight the importance of biocompatibility and long-term stability in neural electrode coatings.

Main Methods:

• Comprehensive review and categorization of reported surface coatings.
• Analysis of coatings based on chemical composition (metals, metal oxides, carbons, conducting polymers, hydrogels).
• Discussion of microstructures, electrochemical properties, fabrication methods, and structure-property correlations.

Main Results:

• Coatings are classified into five main categories based on chemical composition.
• Detailed presentation of microstructures, electrochemical properties, and fabrication techniques.
• Emphasis on the biocompatibility, including foreign-body response, cell affinity, and in-vivo stability.

Conclusions:

• Surface coatings are vital for overcoming limitations of current neural electrodes.
• Understanding structure-property and structure-biocompatibility relationships is key for designing advanced coatings.
• This review provides a framework for developing next-generation multifunctional neural electrode coatings.