Cost-Effective MEMS fabrication and electrode alignment in microfluidic devices for biological detection

Microfabrication is the crux of developing any VLSI or MEMS-based device. Over the years, the entire microfabrication process has been optimized to make it less complicated and cost-effective. Capillary electrophoresis has been widely used as the mode of detection for various analytes in minute concentrations. However, issues like electrode alignment in these devices have always been tricky to handle. In this paper, we have demonstrated some innovative approaches to tackle this problem. We have used the simplest methods and commonly available materials to achieve proper electrode alignment. A PDMS microchannel was created on PMMA (Polymethyl Methacrylate) substrate using a tungsten wire. The two different configurations presented here includes a microfluidic chip with injection point and end column electrode alignment space, and a microchip (with less than 30micrometer microchannel diameter) with an integrated electrode alignment space The repeatability of the fabrication process has also been validated. Analytes were detected via electrochemical detection (capillary electrophoresis) to ensure that the electrodes have been aligned properly.