Characterization of silicon-based insulated channels for capillary electrophoresis

摘要

A new fabrication method to produce miniaturized Transparent Insulating Channels (muTICs) is presented. The process involves Deep Reactive Ion Etching (DRIE), insulating film deposition, anodic bonding and back etching of the silicon. The muTIC process leaves optically-transparent channels that can be cooled very easily due to the thin walls, thus in principle enabling higher electric field strenghts. Because the fragile nature of thin walls limits the practical application of the muTICs, a polymer film is added to reinforce the microstructures. A muTIC design with an injection- and separation channel and containing a 100 mum long injection loop is realized and evalauted. EOF was confirmed by the use of fluorescently labeled, 3 mum diameter beads observed by a CCD camera coupled to a fluorescence microscope. Current/voltage curves were linear up to applied fields of 700 V/cm. For the first itme, silicon-based microchannels have been realized that are suitable for CE. Thus, muTICs, allow for high flexibility in the deisng of insulated channels with respect to dimensions and cross-sectional shapes for anlaytical techniques where insulating materials are required, such as CE.