Y.H. Kim, Y. Woo, J. Jung, J-R Choi, G.M. Kim, B.K. Kang, J-W Sohn
Daegu-Gyeongbuk Medical Innovation Foundation, Korea
pp. 368 - 371
Keywords: PEG hydrogel, nanocomposite, microfluidic chip
A thin and flexible microfluidic chip device using microstructured montmorillonite (MMT) reinforced polyethylene glycol (PEG) nanocomposite molds has been presented to apply miniaturized nanobio-chips. Biocompatible PEG hydrogel with 1-2 wt.% of MMT was used to fabricate environmentally friendly microchip molds. Micro-dot array or microchannel shaped stencils with microstructure patterns in the ranges of 50-700 µm pattern widths were prepared and used as a photomask. The MMT/PEG solution was photopolymerized by simply UV irradiation for 7 seconds at 26 mW/cm2 intensity. Then the microstructures of MMT/PEG hydrogel nanocomposites were obtained by removing the unreacted solution. The microstructured MMT/PEG molds were used to prepare a thin and flexible microfluidic chip. The polydimethylsiloxane (PDMS) solution was placed on the microstructured mold. A doctor blade was used to remove excess PDMS solution on the microstructured mold. The thin PDMS replica, 300-500 µm height, of a microfluidic chip was obtained after peeled-off from the microstructured mold followed by polymerization. The PDMS replica was placed on a polyester film, 100 µm thickness, after plasma treatment. The flexible microfluidic chip was examined by sample manipulation. The present method is rapid and conventional to prepare a thin and flexible microfluidic chip for nanobio-chip applications.