Driving electrochemical reactions at the microscale using CMOS microelectrode arrays

Area of Science:

• Electrochemistry
• Surface Science
• Materials Science

Background:

• Precise pH control at electrode interfaces is crucial for studying pH-dependent electrochemical processes.
• Miniaturized systems are needed to confine electrochemical reactions to small areas.

Purpose of the Study:

• To develop a method for generating localized pH patterns on complementary metal-oxide-semiconductor (CMOS) microelectrode arrays (MEAs).
• To demonstrate the use of these pH patterns for creating polymeric surface patterns and controlling neuronal growth.

Main Methods:

• Utilized high-density CMOS MEAs with switch matrix capabilities to create arbitrary combinations of anodic and cathodic electrodes, generating localized pH patterns.
• Employed additive patterning via in situ polydopamine formation and subtractive patterning by removing poly-L-lysine.
• Demonstrated neuronal growth control on patterned surfaces.

Main Results:

• Achieved unprecedented spatial resolution in generating localized pH patterns on CMOS MEA surfaces.
• Successfully produced polymeric surface patterns using both additive and subtractive electrochemical methods.
• Showcased proof-of-concept for controlling neuronal growth via electrochemically induced surface patterns.

Conclusions:

• The developed platform enables precise, localized pH control on CMOS MEAs for electrochemical patterning.
• The method is compatible with commercial MEAs and requires no custom equipment, ensuring generalizability.
• This technique offers a versatile approach for creating functional surface patterns with applications in neuroscience and beyond.