A novel method was developed to easily fabricate micro-fluidic devices with a low cost. It will be especially useful at preliminary research stages. In the new method, inexpensive commercial air-pressure dispenser was used. Adopting originally developed "wire nozzles", it was verified that fine resist patterns with widths down to 50 mu m were successfully delineated. However, because patterns have to be delineated connecting simple line patterns, it was difficult to delineate trench or hole patterns by painting out a large area. Moreover, sidewalls of the delineated patterns were not sharp. For this reason, easy image-reverse process was thought out. In the novel process, opaque liquid patterns were delineated using the dispenser on a thick negative resist film coated on a substrate, and the resist film was exposed to flood exposure light. As a result, the resist was sensitized except under the opaque liquid patterns. Therefore, trench or hole patterns corresponding to the opaque liquid pattern shapes were obtained after developing the resist. Replicated thick resist patterns have sharply-cut sidewalls, and will be durable for micro-fluidic paths or vessels of biodevices.
