Rapid fabrication of a poly(dimethylsiloxane) microfluidic capillary gel electrophoresis system utilizing high precision machining

Abstract

In this work, we demonstrate a rapid protocol to address one of the major barriers that exists in the fabrication of chip devices, creating the micron-sized structures in the substrate material. This approach makes it possible to design, produce, and fabricate a microfluidic system with channel features >10 microm in poly(dimethylsiloxane)(PDMS) in under 8 hours utilizing instrumentation common to most machine shops. The procedure involves the creation of a master template with negative features, using high precision machining. This master is then employed to create an acrylic mold that is used in the final fabrication step to cast channel structures into the PDMS substrate. The performance of the microfluidic system prepared using this fabrication procedure is evaluated by constructing a miniaturized capillary gel electrophoresis (micro-CGE) system for the analysis of DNA fragments. Agarose is utilized as the sieving medium in the micro-CGE device and is shown to give reproducible (RSD (n= 34) approximately 5.0%) results for about 34 individual separations without replenishing the gel. To demonstrate the functionality of the micro-CGE device, a DNA restriction ladder (spanning 26-700 base pairs) and DNA fragments generated by PCR are separated and detected with laser-induced fluorescence (LIF). The microchip is shown to achieve a separation efficiency of 2.53 x 10(5) plates m(-1).

Effects of insulin-like growth factor 1 and basic fibroblast growth factor on the morphology and proliferation of chondrocytes embedded in Matrigel in a microfluidic platform

“…The microfluidic bioreactor was fabricated using PDMS using rapid prototyping, as described previously (17). Firstly, a design for a device was produced in a computer-aided design (AutoCAD 2007, Autodesk, San Rafael, CA, USA) program.…”

A polymeric master replication technology for mass fabrication of poly(dimethylsiloxane) microfluidic devices

“…The master replication process of heating the acrylic at above 2007C for 2 h in an oven to transform its surface into viscous liquid and sink into the negative features of the aluminum mask could reproduce features from 7 to 20 mm in height. The replication technique was not able to replicate features of more than 20 mm [27], and that was unsuitable for some integration systems with deeper functions for particular analysis.…”

“…McCormick et al [12] used an electroform method to simultaneously replicate multiple nickel electroform "daughter" injection molds from a nickel "mother" template that was prepared from a wet-etched negative silicon template. Another approach involves cutting an aluminum mask with a high-precision mill, and then creating an acrylic master from the aluminum mask [27]. The master replication process of heating the acrylic at above 2007C for 2 h in an oven to transform its surface into viscous liquid and sink into the negative features of the aluminum mask could reproduce features from 7 to 20 mm in height.…”

A Simple Microfluidic Integrated with an Optical Sensor for Micro Flow Injection Colorimetric Determination of Glutathione

“…[6][7][8][9][10][11] The fabrication process consists of two main steps: master mold building and the replication of a PDMS chip from a master mold. There are different ways to construct a master mold, e.g., by patterning dense photoresist meterials on a silicon substrate, 12 etching into a silicon or glass substrate using conventional micromachining processes, 13 the patterning of a UV-cured epoxy resin on a brass block, 14 precision milling the pattern into an aluminium alloy substrate, 15 direct printing of the pattern on a transparency with a laser printer 16 and etching into a photosensitized printed circuit board (PCB) using conventional printed-circuit technology.…”