Micromixing structures for lab-on chip applications

This paper describes the fabrication procedure of micromixers using the novel dry film resist PerMX 3020 (DuPont, USA). The lamination of multiple dry film resist layers on predrilled PMMA plates and the subsequent lithographic patterning of the dry film resist allows for the low-cost fabrication of polymer microfluidic devices within short process times. The covering of patterned microchannels with an additional layer of dry film resist provides a simple way of creating closed microchannels without the need of any further materials or bonding processes. The established process technology was used for the fabrication of 90 degrees zigzag micromixers, which were tested with a fluorescein/water dilution to characterize their mixing behaviour. The comparison of the experimental results with a simulation of the micromixer geometry using the CFD software ANSYS shows a good correlation between the simulation results and the practical experiments. With these polymer micromixers we achieved a mixing efficiency of about 85 to 88%.