Dry film microchips for miniaturised separations.

Area of Science:

• Microfluidics
• Analytical Chemistry
• Materials Science

Background:

• Microfluidic devices offer advantages in miniaturization and efficiency for chemical analyses.
• Developing cost-effective and rapid fabrication methods for microfluidic devices is crucial for widespread adoption.

Purpose of the Study:

• To develop a simple and fast microfabrication process for microfluidic devices using Ordyl SY330 photoresist.
• To characterize the optical properties of the photoresist for fluorescence detection.
• To demonstrate the utility of the fabricated devices for electrophoretic and liquid chromatography separations.

Main Methods:

• Microfluidic devices were fabricated using Ordyl SY330 dry film photoresist and common laboratory equipment (laminator, hot plate, exposure source, drill).
• Optical properties of the photoresist were analyzed using microscopy and spectrophotometry.
• Electrophoretic separations of APTS and derivatised sugars were performed.
• Liquid chromatography applications were demonstrated through fluorescein extraction.

Main Results:

• A microfabrication process yielding 50 µm wide and 30 µm high channels was established, producing four devices in under 1 hour.
• The photoresist exhibited suitable optical transmission (80% between 400-550 nm) and low fluorescence, enabling fluorescence detection.
• High-efficiency electrophoretic separations (40,000 plates) were achieved for derivatised sugars within 30 seconds.
• The fabrication method facilitated easy particle loading for chromatography, demonstrated by fluorescein extraction.

Conclusions:

• A rapid, low-cost microfabrication technique for microfluidic devices using Ordyl SY330 is presented.
• The fabricated devices are suitable for sensitive fluorescence detection and high-performance electrophoretic separations.
• The ease of fabrication and particle integration opens possibilities for microfluidic liquid chromatography applications.