title: Construction of microfluidic chips using polydimethylsiloxane for adhesive bonding.
abstract: A thin layer of polydimethylsiloxane (PDMS) prepolymer, which is coated on a glass slide, is transferred onto the embossed area surfaces of a patterned substrate. This coated substrate is brought into contact with a flat plate, and the two structures are permanently bonded to form a sealed fluidic system by thermocuring (60 degrees C for 30 min) the prepolymer. The PDMS exists only at the contact area of the two surfaces with a negligible portion exposed to the microfluidic channel. This method is demonstrated by bonding microfluidic channels of two representative soft materials (PDMS substrate on a PDMS plate), and two representative hard materials (glass substrate on a glass plate). The effects of the adhesive layer on the electroosmotic flow (EOF) in glass channels are calculated and compared with the experimental results of a CE separation. For a channel with a size of approximately 10 to 500 microm, a approximately 200-500 nm thick adhesive layer creates a bond without voids or excess material and has little effect on the EOF rate. The major advantages of this bonding method are its generality and its ease of use.
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
authors.forename: Hongkai
authors.initials: H
authors.lastname: Wu
authors.forename: Bo
authors.initials: B
authors.lastname: Huang
authors.forename: Richard N
authors.initials: RN
authors.lastname: Zare
mesh_terms: D000268:Adhesiveness; D002484:Cementation / Q000379:methods*; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D012828:Silicones / Q000737:chemistry*; D013718:Tensile Strength
chemical_list: D004129:Dimethylpolysiloxanes; D012828:Silicones; C013830:baysilon