chamber should be stable at 500 mTorr for a successful process. The substrates are
placed inside the chamber exposing the binding surfaces to the RF-plasma. Expo-
sure times can vary from one reactor to another, for example 45 s of exposure are
sufficient using plasma asher (Harrick Pro) at 30 W nominal power. After exposure
the PDMS and substrate are immediately brought in contact, and the left to incubate
at 65C over 2 h. The incubation step is optional, however, it facilitates water
molecule removal from the interface between the substrates and the formation of
bonds. Plasma treatment oxidises the siloxane bonds on the surface of the PDMS
and renders it hydrophilic, as silanol groups are formed. This process is reversible
and takes up to 12 h before PDMS returns to its native hydrophobic state.
References
- Guckenberger DJ, de Groot TE, Wan AMD, Beebe DJ, Young EWK (2015) Micromilling: a
method for ultra-rapid prototyping of plastic microfluidic devices. Lab Chip 15
(11):2364–2378 - Jeon JS, Chung S, Kamm RD, Charest JL (2011) Hot embossing for fabrication of a
microfluidic 3D cell culture platform. Lab Chip 13:325–333 - Steigert J, Haeberle S, Brenner T, Muller C, Steinert CP, Koltay P, Gottschlich N, Reinecke H,
Zengerle R, Ducree J (2007) Rapid prototyping of microfluidic chips in COC. J Micromech
Microeng 17:333–341 - Jensen MF, McCormack JE, Helbo B, Christensen LH, Christensen TR, Geschke O (2004)
Rapid prototyping of polymer microsystemsviaexcimer laser ablation of polymeric moulds.
Lab Chip 4:391–395 - Shin Y, Han S, Jeon JS, Yamamoto K, Zervantonakis IK, Sudo R, Kamm RD, Chung S (2012)
Microfluidic assay for simultaneous culture of multiple cell types on surface or within
hydrogels. Nat Protocols 7:1247–1259. doi:10.1038/nprot.2012.051 - Madou MJ (2002) Fundamentals of microfabrication: the science of miniaturization. CRC
Press, Boca Raton - Nichols KP, Eijkel JCT, Gardeniers HJGE (2008) Nanochannels in SU-8 with floor and ceiling
metal electrodes and integrated microchannels. Lab Chip 8:173–175 - Berthier E, Young EWK, Beebe D (2012) Engineers are from PDMS-land, biologists are from
Polystyrenia. Lab Chip 12:1224–1237 - Armani D, Chang L, Narayan A (1991) Re-configurable fluid circuits by PDMS elastomer. In:
Proceedings of MEMS 1991, Orlando, pp 222–227. doi:10.1109/MEMSYS.1999.746817 - Kyung M, Rogers JA (2003) A photocurable poly(dimethylsiloxane) chemistry designed for
soft lithographic molding and printing in the nanometer regime. J Am Chem Soc
125:4060–4061 - Datta P, Goettert J (2006) Method for polymer hot embossing process development. Microsyst
Technol 13(3):265–270 - He Y, Fu J-Z, Chen Z-C (2008) Optimization of control parameters in micro hot embossing.
Microsyst Technol 14(3):325–329 - Grzybowski A, Haag R, Bowden N, Whitesides GM (1998) Generation of micrometer-sized
patterns for microanalytical applications using a laser direct-write method and microcontact
printing. Anal Chem 70:4645–4652 - Tangwarodomnukun V, Chen HY (2015) Laser ablation of PMMA in air, water, and ethanol
environments. Mater Manuf Process 30:685–691 - Teixidor D, Orozco F, Thepsonthi T, Ciurana J, Rodrı ́guez CA, O ̈zel T (2013) Effect of
process parameters in nanosecond pulsed laser micromachining of PMMA-based
3 Manufacturing Methods Overview for Rapid Prototyping 101