Hybrid integrated PDMS microfluidics with a silica capillary

Area of Science:

• Microfluidics
• Analytical Chemistry
• Materials Science

Background:

• Polydimethylsiloxane (PDMS) and fused silica are widely used materials in microfluidic devices.
• Conventional capillary electrophoresis (CE) systems often face challenges with sample injection and integration with other analytical techniques.
• Developing modular and reusable microfluidic systems is crucial for efficient analytical workflows.

Purpose of the Study:

• To develop a novel hybrid integrated PDMS microfluidics and silica capillary (iPSC) module.
• To demonstrate a leakage-free method for capillary electrophoresis (CE) sample injection using a single high-voltage source.
• To enable the direct application of established CE protocols and facilitate coupling with mass spectrometry.

Main Methods:

• Fabrication of the iPSC module involves a three-step method: submerging a fused silica capillary in PDMS prepolymer, cross-linking, and punching inlets.
• The modular design allows extensive reuse of the capillary by replacing the attached fluidic module.
• Integration of PDMS microfluidics with fused silica capillaries enables direct application of CE protocols.

Main Results:

• The iPSC modules provide a novel architecture for leakage-free CE sample injection.
• The system requires only a single high-voltage source and one pair of electrodes for operation.
• The modular approach allows for extensive capillary reuse and adaptation to different experimental needs.

Conclusions:

• The developed iPSC modules offer a versatile and efficient platform for CE separations.
• This technology simplifies complex analyte analysis and facilitates coupling with electro-spray ionization mass spectrometry (ESI-MS).
• The fabrication method is simple, quick, and suitable for creating integrated microfluidic devices.