High fidelity prototyping of PDMS electrophoresis microchips using laser-printed masters

Toner-based fabrication technology has appeared as one of the simplest and fastest techniques to produce low-cost microfluidic devices. The instrumental simplicity and fabrication easiness make this fabrication technique quite suitable to be implemented in developing countries where the availability of resources is limited. In this study, the prototyping fidelity of poly(dimethylsiloxane) (PDMS) electrophoresis microchips has been evaluated using laser printed masters. The desirable layout of the microfluidic devices was first drawn in graphic software and then printed on the surface of transparency films by an office laser printer with 1,200-dpi resolution. The masters printed on transparency films were directly used to replicate the microfluidic structures in PDMS. The analysis of the dimensions of the printed toner lines has revealed that their thickness depends on the line width. For lines with width between 50 and 300 mu m, the height ranged from 4.9 +/- A 0.2 to 10.4 +/- A 0.1 mu m. The prototyping fidelity achieved for channels defined with width between 50 and 300 mu m was higher than 96 %. Furthermore, it has been demonstrated that a single master can be used to replicate at least ten PDMS chips with great reproducibility. The analytical performance of the replicated PDMS microchips for electrophoresis separation has revealed good chip-to-chip and injection-to-injection reproducibility. Based on the results achieved, it is possible to conclude that toner-based masters can be a useful tool for researchers with restricted access to conventional microfabrication technologies.