The quartz chamber AutoGlow plasma system has been used for over 10 years for plasma surface activation in the bonding of PDMS to glass substrates. Most users use an O2 plasma, 30-50 watts, .5 Torr to 1.2 Torr.
The AutoGlow can process as low as 10 watts and up to 300 watts in one watt increments
From page 6–discussion of plasma surface activation and the bonding of glass and PDMS
Microfluidic chips were manufactured by conventional soft lithography.27 Molding masters were fabricated by spin coating
SU-8 negative photoresist (MicroChem Corp., Newton, MA) onto 6 inch silicon wafers and transferring the fluidic features from photomasks (CAD/Art Services, Bandon, OR) by contact lithography with an OAI Hybralign Series 200 aligner (OAI, San Jose, CA). Chips contained channels with two depths: deep channels with low hydrodynamic resistance (100 _ 10 mm) for transporting fluid from external ports to the functional regions of the chip, and shallow channels (20 _ 1 mm) for droplet manipulation and detection. SU-8 photoresists 2100 and 2025 were used for deep and shallow channels respectively. Polydimethylsiloxane (PDMS) (Sylgard_ 184, Dow Corning, Midland, MI) chips were molded from the negative masters within mold housings of custom design. Glass cover slides were permanently bonded to the fluidic side of the chips by plasma surface activation in an AutoGlow oxygen plasma system (Glow Research, Phoenix, AZ) followed by immediate contact bonding.
To create hydrophobic surfaces, the microfluidic channels as well as the fluid-exposed surfaces of the emulsion vials (see Fig. 1) were treated for _2 min with 1H,1H,2H,2H-perfluorodecyltrichlorosilane (Alfa Aesar, Ward Hill, MA) dissolved in FC-3283 (3M Specialty Materials, St Paul, MN) prepared as a mixture of18 g silane in 100 mL solvent.
From: Lab on a Chip: Lab Chip, 2011, 11, 2167
Qun Zhong,a Smiti Bhattacharya,a Steven Kotsopoulos,a Jeff Olson,a Valerie Taly,b Andrew D. Griffiths,b
Darren R. Linka and Jonathan W. Larson*