Due to the high flexibility and versatility in the process development of microfluidic devices, an epoxybased, high-aspect ratio photoresist SU-8 is now attracting attention as the main structuring material of the fluidic channels. Manipulation of the surface properties of SU-8 channel wall is critical to attach functional films such as enzyme-immobilized layers or biocompatible layers. We describe a new in situ patterning method to form a hydrogel film on SU-8 by a photografted polymerization procedure. The hydrophobic surface of SU-8 is modified using a surface bound initiator HCPK (1-hydroxycyclohexyl phenyl ketone). A p-HEMA (poly-2-hydroxyethylmethacrylate) hydrogel film is grafted by photopolymerization of solution-phase precursors on the modified surface. The contact angle measurements reveal that the hydrophilicity was increased after the grafting. This is a promising in situ formation method of patterned functional films within a completed microfluidic channel.
Z. Gao et al., "Surface Modification of SU-8 by Photografting of Functional Polymers for Lab-on-a-Chip Applications," Proceedings of the 2006 5th IEEE Conference on Sensors (2006, Daegu), Institute of Electrical and Electronics Engineers (IEEE), Jan 2006.
The definitive version is available at http://dx.doi.org/10.1109/ICSENS.2007.355733
2006 5th IEEE Conference on Sensors (2006: Oct. 22-25, Daegu)
Chemical and Biochemical Engineering
Electrical and Computer Engineering
Keywords and Phrases
Lab-On-A-Chip; Polymer Blends; Polymer Films; Surface Treatment; BioMEMS; Microfluidics; Miniature electronic equipment; Photoresists; Polymerization
Article - Conference proceedings
© 2006 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.