Low cost integration of 3D-electrode structures into microfluidic devices by replica molding

Area of Science:

• Microfluidics
• Materials Science
• Electrical Engineering

Background:

• Microfluidic devices are essential for lab-on-a-chip applications.
• Integrating functional components like electrodes into microfluidic devices can be complex and costly.
• Polydimethylsiloxane (PDMS) is a common material for microfluidic device fabrication due to its biocompatibility and ease of use.

Purpose of the Study:

• To present a novel, low-cost replica molding method for fabricating microfluidic devices with integrated 3D-composite electrodes.
• To demonstrate the versatility and limitations of the fabrication method across different device geometries.
• To characterize the electrical properties of the developed composite electrode material.

Main Methods:

• A cost-effective replica molding process was developed, utilizing standard multilayer SU-8 photolithography for micro mold fabrication.
• The method avoids the need for cleanroom facilities, expensive materials, or specialized equipment post-mold fabrication.
• Various microfluidic device geometries were successfully fabricated to showcase the method's capabilities.

Main Results:

• The fabrication method allows for the low-cost integration of 3D-composite electrodes into PDMS microfluidic devices.
• Electrical properties of the composite electrode material were characterized, confirming their suitability for microfluidic applications.
• A proof-of-concept device for particle concentration using AC-dielectrophoresis was successfully demonstrated.

Conclusions:

• The developed replica molding technique offers an accessible and affordable approach for creating advanced microfluidic devices with integrated 3D-composite electrodes.
• This method has significant potential for various microfluidic applications, including particle manipulation and sensing.
• The fabrication process is scalable and adaptable for different microfluidic designs.