Fabrication of microchip electrophoresis devices and effects of channel surface properties on separation efficiency

This paper describes the influence of chip material on the separation efficiency in microchip electrophoresis using quartz, glass, polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), and glass hybrid as the microchip material. The fabrication processes for each microchip are described in detail. We introduce a new fabrication method for a glass chip using amorphous silicon on the glass surface as an etch mask and a bonding interface for anodic bonding. The microchannel structures in each microchip were compared using a scanning electron microscope or profilometer. We investigated the mobilities and bandwidths of electroosmotic flow (EOF) and analytes in microchip electrophoresis. Significant band broadening was observed in a microchip composed of a hybrid material (glass and silicon dioxide membrane) compared with a microchip of single material due to the nonuniformity of the surface charge density.