Microfabrication of Nonplanar Polymeric Microfluidics

Area of Science:

• Materials Science
• Engineering
• Biotechnology

Background:

• Microfluidics technology has enabled significant advancements across various scientific fields for over 40 years.
• Traditional microfluidic chip fabrication often limits designs to planar geometries, restricting applications requiring three-dimensional structures.
• Developing methods for creating nonplanar microfluidic devices is crucial for expanding their utility in complex biological and chemical analyses.

Purpose of the Study:

• To report a novel fabrication approach for creating nonplanar, three-dimensional microfluidic chips using micromachining.
• To optimize micromachining parameters for enhanced surface contour definition in nonplanar mold inserts.
• To demonstrate the fabrication of functional nonplanar microfluidic devices using both poly(methyl methacrylate) (PMMA) and polydimethylsiloxane (PDMS).

Main Methods:

• Micromachining of nonplanar poly(methyl methacrylate) (PMMA) mold inserts was performed, focusing on optimizing parameters for surface smoothness and contour definition.
• Nonplanar PMMA/PMMA microfluidic chips with S-shape microchannels were fabricated using solvent bonding.
• Nonplanar polydimethylsiloxane (PDMS)/PMMA microfluidic chips, including a microlens array (MLA), were fabricated using nonplanar mold inserts and solvent bonding.

Main Results:

• Optimized micromachining parameters successfully enhanced the smoothness and definition of surface contours on nonplanar PMMA mold inserts.
• Functional nonplanar microfluidic chips, including an S-shape microchannel and a microlens array, were successfully fabricated.
• The study demonstrated the versatility of the micromachining approach for creating both all-PMMA and PDMS/PMMA nonplanar microfluidic devices.

Conclusions:

• Micromachining offers an effective method for fabricating nonplanar microfluidic chips directly on polymeric substrates.
• The developed technique facilitates the creation of nonplanar mold inserts for manufacturing advanced PDMS/PMMA microfluidic chips.
• This approach enables the development of microfluidic devices with integrated three-dimensional features for specialized in vitro characterization applications.