Solvent bonding of poly(methyl methacrylate) microfluidic chip using phase-changing agar hydrogel as a sacrificial...

Area of Science:

• Materials Science
• Chemical Engineering
• Analytical Chemistry

Background:

• Microfluidic chips are essential for miniaturized analytical systems.
• Traditional fabrication methods for poly(methyl methacrylate) (PMMA) microfluidic chips often involve high temperatures or complex procedures.
• Achieving reliable and room-temperature bonding for PMMA microfluidic devices remains a challenge.

Purpose of the Study:

• To develop a facile and effective solvent bonding method for fabricating PMMA microfluidic chips.
• To utilize a phase-changing agar hydrogel as a sacrificial layer to protect microchannels during bonding.
• To demonstrate the performance of the fabricated microfluidic chips in analytical applications.

Main Methods:

• A solvent bonding technique was developed using 1,2-dichlororethane for PMMA.
• Molten agar hydrogel was used to form sacrificial layers within the microchannels and reservoir ports.
• Agar hydrogel protected channels from solvent ingress and PMMA deformation during bonding.
• Agar hydrogel was subsequently removed by melting and applying pressure.

Main Results:

• High-quality bonding of PMMA microfluidic chips was achieved at room temperature.
• Optical and scanning electron microscopy confirmed the integrity of the sealed microchannels.
• The fabricated microfluidic chips were successfully applied to electrophoresis separation.
• Contactless conductivity detection was employed for the separation and detection of three cations.

Conclusions:

• The agar hydrogel-based solvent bonding method provides a simple and effective approach for PMMA microfluidic chip fabrication.
• This room-temperature bonding technique is suitable for creating high-quality microfluidic devices.
• The developed microfluidic chips demonstrate excellent performance in microchip electrophoresis applications.