title: Micro magnetic stir-bar mixer integrated with parylene microfluidic channels.
abstract: Previously, we reported a micro magnetic stir-bar mixer driven by an external rotating magnetic field and its rapid mixing performance in polydimethyl-siloxane (PDMS) channels. The PDMS piece with embedded fluid channels were manually aligned to a glass substrate and assembled. In this paper, we report the fabrication and testing results of a micro magnetic stir-bar monolithically integrated in parylene surface-micromachined channels with improved design features, including small tolerance of the stir-bar to channel wall (10 microm). Using of parylene based microchannels with improved design not only provides improved mixing, but also eliminates certain problems associated with PDMS-based channels. For example, porosity of PDMS causes evaporation and absorption of chemicals and thus channels made of PDMS are prone to cross-contamination. We have also demonstrated that the magnetic stir-bar can be used to pump liquid in micro channels.
authors.affiliation: Micro Actuators, Sensors and Systems Group, Micro and Nanotechnology Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Kee Suk
authors.initials: KS
authors.lastname: Ryu
authors.forename: Kashan
authors.initials: K
authors.lastname: Shaikh
authors.forename: Edgar
authors.initials: E
authors.lastname: Goluch
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Fan
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
mesh_terms: D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008280:Magnetics / Q000295:instrumentation*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods; D009038:Motion; D009757:Nylons / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D014992:Xylenes / Q000737:chemistry*
chemical_list: D004129:Dimethylpolysiloxanes; D009757:Nylons; D011108:Polymers; D014992:Xylenes; C085707:poly(dimethylsiloxane)-polyamide copolymer; C011055:parylene