Powder-blasting technology as an alternative tool for microfabrication of capillary electrophoresis chips with integrated conductivity sensors

The fabrication and characterization of a microfluidic device for capillary electrophoresis applications is presented. The device consists of a glass chip which contains a single separation channel as well as an integrated co nductivity detection cell. In contrast to most microfluidic glass devices t he channels are not wet etched in HF but machined by the newly developed mi cro powder-blasting technique which allows the creation of microstructures below 100 mum, and additionally makes parallel hole machining at very low c osts outside the cleanroom environment possible [1, 2]. The integration of the conductivity detector was achieved by leading two thin-film metal elect rodes inside the separation channel. For rapid sample injection the chip is mounted inside an autosampler-based capillary electrophoresis platform. Th e detection electrodes for conductivity detection are read out by lock-in a mplifier electronics. First measurements show the successful separation of various ions in the sub-millimeter range.