Μflu12-133 Control of Flow and Protein Adsorption on Plasma Nanotextured Polymeric Microfluidics

Plasma processing is demonstrated as a generic technology to fabricate, roughen, control the wetting properties, create well controlled passive hydrophobic valves, and finally also control the protein adsorption in polymeric microfluidic channels. Lithography and deep anisotropic O2 plasma etching directly on polymeric substrates were utilized to pattern microchannels, at conditions where very controllably rough bottom walls were obtained. Alternatively, hot embossing of a polymer with a master followed by plasma nanotexturing was used to controllably roughen the microchannels. Where desirable, the rough surfaces were hydrophobized by means of a C4F8 plasma deposition step through a stencil mask creating hydrophobic/superhydrophobic stripes / patches. The superhydrophobic patch plays the role of an on/off valve with predesigned threshold pressure for opening determined by the channel dimensions and roughness of the patch. In such microchannels, protein adsorption was controlled by the surface roughness showing null adsorption on superhydrophobic stripes and greatly enhanced adsorption on rough superhydrophilic stripes. Such control inside microchannels can be applied in autonomous microfluidic lab on chip systems for bio analysis. *[email protected] MICROFLUIDICS2012 Proceedings of the 3 European Conference on Microfluidics Microfluidics 2012 Heidelberg, December 3-5, 2012 © SHF 2012 2