Critical points in the fabrication of microfluidic devices on glass substrates

Miniaturized total analysis systems are becoming a powerful tool for analytical and bioanalytical applications. In this work, microfluidic channels have been fabricated on glass substrates using photolithography and wet etching. Although these techniques are well-known and established, the influence of different parameters on the fabrication process of microchannels is of great importance. Thus, practical aspects and critical points of the procedure were considered and evaluated. Resulting glass chips with microfluidic channels were sealed with a cover plate to enclose the channels. Different low and high temperature bonding procedures have been evaluated. Microfluidic chips have been used in combination with a metal-wire end-channel amperometric detector for capillary electrophoresis (CE). The microfluidic channels and the amperometric detector have been tested using p-aminophenol as model analyte demonstrating that these devices are useful for analytical applications.