Durable hydrophilic microchannels with controlled morphology by the direct molding method
Tae-Ho Yoon1, Ming Li, Lan-Young Hong
1Center of Applied Microfluidic Chemistry, Chungnam National University, Daejeon, 305-764, South Korea.
Analytical Chemistry
|February 26, 2011
Summary
Researchers developed a new hydrophilic microchannel using a hybrid resin. This novel material enables spontaneous water flow and improved separation performance in capillary electrophoresis (CE).
Area of Science:
- Materials Science
- Microfluidics
- Analytical Chemistry
Background:
- Microfluidic devices are crucial for various applications, but controlling fluid flow and surface properties remains challenging.
- Polydimethylsiloxane (PDMS) is a common material for microchannels, but it can suffer from surface fouling and limited hydrophilic properties.
- Developing microchannels with enhanced hydrophilicity and controlled flow is essential for improving microfluidic applications.
Purpose of the Study:
- To present a novel laminated hydrophilic microchannel fabricated using a hydrophilic organic-inorganic hybrid (HP) resin.
- To demonstrate spontaneous self-wetting flow in these microchannels without external pumping.
- To evaluate the performance of HP resin-based capillary electrophoresis (CE) modules for enhanced separation.
Main Methods:
- Fabrication of hydrophilic microchannels using direct micromolding and facile bonding of an HP resin between polydimethylsiloxane (PDMS) substrates.
- Shaping microchannel cross-sections into regular rectangular or complex mouth-throat structures.
- Characterization of capillary flow velocity, zeta potential, and electro-osmotic flow (EOF) properties.
- Demonstration of amino acid and DNA separation using an HP resin-based CE module.
Main Results:
- Spontaneous self-wetting flow of water was achieved in HP microchannels without mechanical pumping or electric fields.
- Capillary flow velocity was controllable by varying channel size.
- The HP channel surface exhibited glass-like zeta potential for pH > 3, with high EOF velocity (4.7 × 10(-4) cm(2)/V·sec at pH 9.0).
- HP resin-based CE modules showed higher resolution, shorter retention times, and improved repeatability and durability compared to PDMS CE modules, with antifouling properties.
Conclusions:
- The developed HP resin microchannels offer a facile and effective method for creating self-wetting hydrophilic channels.
- The HP resin provides excellent surface properties for microfluidic applications, including controllable flow and significant EOF.
- HP resin-based CE modules present a superior alternative to PDMS for high-resolution, repeatable, and durable separations with antifouling capabilities.
