Deep microstructuring in glass for microfluidic applications

Glass is widely used as a structural and functional material in micro-total-analysis-systems. Two low-cost techniques have been used to produce deep and vertical microstructures into glass. A commercially available photosensitive glass (Foturan(TM)) is patterned by photolithography and etched in an HF solution for the construction of a microfluidic component. Channels and reservoirs were bonded to a poly(dimethylsiloxane) cover. A two-level structure with various depths (reservoirs and channels) was also made by a double exposure through two different masks. The other technique uses micro-ultra-sonic machining to form channels by erosion into borosilicate glass (Pyrex 7740). The two structuring techniques are compared with respect to surface profiles and surface states.