Wired Microfabricated Electrochemical Systems

Area of Science:

• Electrochemistry
• Microfluidics
• Materials Science

Background:

• Liquid junctions in microfabricated electrochemical devices can be problematic.
• Metal wires offer a potential alternative for solution connections.
• Canceling interfacial potentials is crucial for metal wire performance.

Purpose of the Study:

• To evaluate metal wires as a substitute for liquid junctions in microfluidic electrochemical systems.
• To investigate methods for canceling interfacial potentials at metal wire junctions.
• To demonstrate the utility of metal wire junctions in various electrochemical techniques.

Main Methods:

• Fabrication of microfluidic electrochemical devices using metal wires as junctions.
• Comparison of cyclic voltammograms between devices with liquid junctions and metal wires.
• Utilizing iridium wires with iridium oxide coatings.
• Equalizing pH in working and reference electrode compartments.
• Application in voltammetry, amperometry, and potentiometry.

Main Results:

• Metal wires demonstrated performance comparable to liquid junctions.
• Interfacial potentials at metal wire junctions were effectively canceled, especially with iridium oxide.
• The system allowed for reliable integration of common reference electrodes.
• Automated electrochemical control of solution transport was achieved.

Conclusions:

• Metal wires, particularly iridium oxide-coated iridium, are a viable alternative to liquid junctions in microfluidic electrochemical devices.
• Effective cancellation of interfacial potentials is key to their successful application.
• This technology facilitates advanced applications like multi-electrode systems and automated microfluidic control.