New ‘monolithic’ templates and improved protocols for soft lithography and microchipfabrication

Abstract

We report a new method for fast prototyping and fabrication of polydimethylsiloxane(PDMS) and plastic microfluidic chips. These methods share in common the preparationof monolithic masters which includes the fabrication of the planar support, the‘negative pattern’ of the microchannels and the fluidic connectors. The monolithictemplates are extremely robust compared to conventional ones made of silicon andSU-8, and easier to produce and cheaper than all-silicon or electroplated templates. Incontrast to the above-mentioned methods, our process allows one to cast bothmicrometre- (e.g. the microchannel) and millimetre-sized structures (e.g. the fluidicconnection to the outer world) in a single fabrication step. The ‘monolithic template’strategy can be used to fabricate both elastomeric (e.g. poly(dimethyl siloxane (PDMS))polyester thermoset masters and glassy polymeric (e.g. cyclic olefin copolymer (COC))devices. In this study we also report on one step fabrication of elastomer chips and onsurface modifications of the above mentioned monolithically fabricated masters in order toimprove separation of the chip from the template.