A rapid, inexpensive surface treatment for enhanced functionality of polydimethylsiloxane microfluidic channels
John H L Beal1, Andrea Bubendorfer, Tim Kemmitt
1Nano- & Micro-Fluidics Team, Industrial Research Ltd., 69 Gracefield Road, P.O. Box 31310, Lower Hutt 5040, New Zealand.
Biomicrofluidics
|July 31, 2013
Summary
Researchers developed a fast, affordable method to coat polydimethylsiloxane (PDMS) microfluidic channels with a glass-like layer using alkoxysilanes. This surface modification enhances channel performance and allows for further chemical functionalization.
Area of Science:
- Materials Science
- Chemical Engineering
- Microfluidics
Background:
- Polydimethylsiloxane (PDMS) is widely used in microfluidics due to its rapid prototyping capabilities.
- Native PDMS surfaces exhibit limitations in wettability and electroosmotic flow (EOF) stability.
- Achieving glass-like surface properties in PDMS is desirable for improved microfluidic device performance.
Purpose of the Study:
- To develop a rapid and inexpensive method for modifying the interior surfaces of PDMS microfluidic channels.
- To impart desirable wetting and electroosmotic properties to PDMS, mimicking those of glass.
- To enable selective surface modification for high-throughput processing or specific area functionalization.
Main Methods:
- A novel coating technique utilizing alkoxysilanes to create an integral silicaceous layer on PDMS channel interiors.
- Application of the coating method on open PDMS faces before channel enclosure or by flowing reagents through preformed channels.
- Surface modification using tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES).
Main Results:
- The alkoxysilane coating method successfully created a stable silicaceous layer on PDMS channel surfaces.
- Modification with TEOS enhanced PDMS wettability and stabilized electroosmotic flow (EOF) rates compared to unmodified PDMS.
- Modification with APTES introduced amine functionalities, enabling subsequent chemical derivatization of the PDMS surface.
Conclusions:
- The developed alkoxysilane-based method offers a versatile and efficient approach to functionalize PDMS microfluidic channels.
- This technique effectively combines the advantages of PDMS rapid prototyping with the superior surface properties of glass.
- The surface-modified PDMS provides a robust platform for advanced microfluidic applications requiring tailored surface chemistry and improved fluid dynamics.
