Digital light processing 3D printing of microfluidic devices targeting high-pressure liquid-phase separations

Area of Science:

• Analytical Chemistry
• Materials Science
• Chemical Engineering

Background:

• Microchannel devices are crucial for miniaturized analytical systems.
• High-pressure liquid chromatography (HPLC) separations demand robust microfluidic interfaces.
• 3D printing offers rapid prototyping for custom microfluidic device fabrication.

Purpose of the Study:

• To develop 3D printed microchannel devices for HPLC using Digital Light Processing (DLP).
• To investigate the impact of printing parameters on microchannel dimensions and surface quality.
• To assess the pressure resistance and chromatographic performance of the fabricated devices.

Main Methods:

• Utilized a commercial DLP 3D printer with acrylate resin to fabricate microchannels (100-500 µm i.d.).
• Systematically varied layer thickness (20 µm) and exposure time (0.7-1.1 s) to optimize channel geometry and surface roughness.
• Integrated devices into a custom aluminum chip holder with PEEK nanoports for HPLC interfacing.
• Measured pressure resistance up to 650 bar and demonstrated in-situ synthesis of a polymer monolithic support.

Main Results:

• Achieved minimized surface roughness (<20%) for both squared and circular channel designs.
• Demonstrated high pressure resistance of 650 bar with low variability (1.5% RSD).
• Successfully synthesized a polymer monolithic support within a 500 µm i.d. microchannel.
• Performed a proof-of-concept reversed-phase gradient separation of intact proteins.

Conclusions:

• DLP 3D printing is a viable method for fabricating high-performance microchannel devices for HPLC.
• Optimized printing parameters enable precise control over microchannel dimensions and surface properties.
• The developed microdevices exhibit excellent pressure tolerance and are suitable for complex chromatographic separations.