Microfabricated Channels and Fluid Control Systems for Integrated Flow Injection Analysis

Abstract

An integrated flow injection analysis (FIA) system on a glass chip has been achieved in the channels with various scales. It is intended that the channels of 10 to 200 μm wide are used for analytical chemistry and that those of less than 1 μm wide for physical chemistry. The channel of 200 μm wide and 100 μm deep is fabricated by CO2 laser cutting and thermally bonding. The isotropic wet etching with HF/NH4F is used for the channel with 30 μm wide and 10 μm deep. The etched Pyrex glass and the cover Pyrex glass are thermally bonded together. Further, the anisotropic dry etching such as reactive ion etching is performed for the channel with 1 μm wide and 1 μm deep. The etched Pyrex glass is anodically bonded to the Si wafer covered with silicon oxide film (800nm thick), which is consequently used as a cover glass. A new anisotropic etching technique using fast atom beam is carried out and the channel of 50 nm wide and 360 nm deep can be obtained. In all of the FIA systems, the chelating reaction of Fe(II) and o-phenanthroline has been realized.