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.

Meeting Name

2006 5th IEEE Conference on Sensors (2006: Oct. 22-25, Daegu)


Chemical and Biochemical Engineering

Second Department

Electrical and Computer Engineering

Keywords and Phrases

Lab-On-A-Chip; Polymer Blends; Polymer Films; Surface Treatment; BioMEMS; Microfluidics; Miniature electronic equipment; Photoresists; Polymerization

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 2006 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jan 2006