No.2（2007）7.Fabrication of micro structure for nano liter volume column device

Masanori Ishizuka

In this paper, a new fabrication method of the micro column device to separate chemical or bio material is presented. The micro channel size was of 100 μm width and of 20 μm depth. A 15 μm height dam structure was design to hold the micro beads inside the channel. The dam structure embedded micro channel was realized by conventional micro fabrication technique such as photolithography, micro electroplating and micro molding of plastic material. To fabricate the dam structure, two step silicon dry etching process was introduced. Since two types of material were used as hard mask for each etching process, two silicon molds of different height were realized. The silicon mold structure was transcribed into electroplating nickel mold. Pure and cured poly (dimethylsiloxane) is injected on a nickel mold. Finally, PDMS micro column structure was released. We verify the dam structure function as to stop micro beads. PDMS has been widely used for micro fluidic device application due to easy fabrication and low cost. Some PDMS reactors such as PCR chips, synthesis reactors have been reported. In micro fluidic applications for chemical analysis and chemical reactions, plastic material micro column are getting substantial attraction. In particular, our issue is to fabricate dam structure embedded micro channels.

Keywords

micro fabrication, dam structure, mold, electroplating, PDMS

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