AVS 50th International Symposium
    Microelectromechanical Systems (MEMS) Tuesday Sessions
       Session MM-TuP

Paper MM-TuP2
Capillary Electrophoresis On-chip: Glass and Polymeric Materials for Cell Fabrication

Tuesday, November 4, 2003, 5:30 pm, Room Hall A-C

Session: Poster Session
Presenter: Y. Mourzina, Research Centre Juelich, Germany
Authors: Y. Mourzina, Research Centre Juelich, Germany
A. Offenhaeusser, Research Centre Juelich, Germany
Correspondent: Click to Email
The advances of bioanalytical chemistry and biotechnology stimulated interest in on-chip integrated microfluidic systems and analytical techniques for accurate, precise and high-effective analysis of proteins. Capillary electrophoresis on chip is rapidly developing field by learning on fabrication technologies in the field of MEMS. In the present work, two approaches to realize 3-D microstructures in glass wafers or polymeric materials for on-chip capillary electrophoretic separation of proteins are presented. The microchannel configurations in Pyrex glass wafers have been realized by means of photolithography, thin film deposition and etching steps. The dimensions of the channels are 6 to 16 µm depth and 40 to 120 µm width. Different processing sequences are compared. The structures have been visualized by means of REM to observe the profile and the edge roughness. Special attention has been paid to the optimization of the deposition of the metal thin films as sacrificial layer for glass etching, and to the influence of the composition of the etch solution on glass etch velocity, undercut phenomenon and the quality of the structures. Soft lithography is presented as an alternative approach to realize microfluidic channels in polymeric material. The master has been fabricated of the high aspect ratio SU 8 photoresist on Si wafers. Depending on the type of photoresist and the parameters of processing, the masters with different height of the structures (10 to 25 µm) have been obtained. The master has been used for microreplication in polymer PDMS. The dimensions of the separation channels of the polymeric devices are 10 to 25 µm depth and 20 to 80 µm width. Fluorescent microscopy was used to visualize the microchannels. To validate the performance of on-chip electrophoresis, the results of the separation of phosphoproteins in the prepared devices will be compared with the resolution of the conventional gel electrophoresis.