A Poly(dimethylsiloxane) Microfluidic Channel Coated with Poly-p-xylylene for Nanocrystal Growth Applications

Abstract

Applications of microfluidic device fabricated in poly(dimethylsiloxane) (PDMS) have been limited to water-based analysis rather than nonpolar solvent based chemistry due to PDMS swelling problem occurring by absorption of the solvents. The absorption and swelling causes PDMS channel deformation in shape and changes the cross sectional area, making it difficult to control the flow rate and concentrations of solution in PDMS microfluidic channels. We propose that poly-p-xylylene polymers (parylenes) were chemical vapor deposited on the surfaces of PDMS channels to alleviate the effect of solvents on the absorption and swelling. The parylene coated surface sustains 3hours with a small volumetric change (less than 22% of PDMS swelling ratio). By generating an air-nonpolar solvent interface based on droplets in PDMS channel, we confirmed poly-p-xylylene coated PDMS microfluidic channels have the potential to be applicable to nanocrystal growth using nonpolar solvents. ⓒ 2014 DGIST