Fabrication of microfluidic chip and its application

Design and fabrication of microfluidic chip on polymethylmethacrylate (PMMA) substrates for analytical chemistry and biomedical-related application using novel microfabrication methods based on automatic fabrication system are described. The image of microchannels is transferred from nickel mold possessing the inverse image of the microfluidic chip to plastic plates by using hot embossing methods. The microstructure on nickel mold is formed based on UV-LIGA technology. In this study, the nickel mold has been made from nickel micro electroforming based on the epoxy-based negative ultra-thick SU-8 photoresist. The micro nickel mold can be used repeatedly to replicate cheap and disposable microfluidic chip. The reproducibility of the hot embossing method is evaluated using 6 channels on different PMMA plastics. The relative standard deviation of the channel profile (depth and width direction) on the plastic chips is less than 2%. In this study, the PMMA microfluidic chips have been demonstrated as a microcapillary electrophoresis device for pharmaceutical separation and detection.