Abstract
Capillary electrophoresis is one of the fundamental methods for biochemical analysis utilizing difference of electrophoretic mobility in electric field. Microchip Capillary Electrophoresis (MCE) offer faster separation and higher separation. Recently, this method is introduced to many fields, chemical and biological analysis. Many devices for MCE, made by glass and quartz, is fabricated by chemical etching. This way, however, is not good for minituarization and integration, because of its isotropic fabrication property, required many process and expensive fabrication costs of glass. Moreover, CE is very sensitive for residual substances of previous analytes, particularly for clinical measurement. For this reason, we try to make cheaper and disposable electrophoresis device. One approach to overcome theses problems is the usage of polymer materials for chip instruments. Advantage of plastic fabrication is a possibility to make prototyping by high accuracy mold, such as hot embossing and injection molding for mass production. We propose a micro fabrication process for plasric capillary electrophoresis chips using UV polymerization technique. This process only consists of only photolithography. We choose plastic substrate, that is able to use rapid prototyping, instead of glass and quartz. Here is used photosensitive polymer and silicon elastomer as structural material, respectively. Poly-dimethylsiloxane (PDMS) for thermal molding process, and SU-8 (thick negative photoresist) for UV polymerization is used for fine chip structures. Devices were evaluated characteristic difference by surface electric charge. This difference is measured by Electro Osmotic Flow (EOF), that is generated by surface electric charge. EOF is measured by fluorescence detection adopted neutral fluorescence dye as a sample.
