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

Abstract

The fabrication and characterization of a microfluidic device forcapillary electrophoresis applications is presented. The device consists of aglass chip which contains a single separation channel as well as an integratedconductivity detection cell. In contrast to most microfluidic glass devicesthe channels are not wet etched in HF but machined by the newly developedmicro powder-blasting technique which allows the creation of microstructuresbelow 100 µm, and additionally makes parallel hole machining at very lowcosts outside the cleanroom environment possible [1, 2]. The integration ofthe conductivity detector was achieved by leading two thin-film metalelectrodes inside the separation channel. For rapid sample injection the chipis mounted inside an autosampler-based capillary electrophoresis platform. Thedetection electrodes for conductivity detection are read out by lock-inamplifier electronics. First measurements show the successful separation ofvarious ions in the sub-millimeter range.