Rapid prototyping of microfluidic channel using atmospheric pressure plasma jet

A method for rapidly fabricating a microfluidic system using a plasma jet is proposed in this work. Plasma is known for being able to modify the hydrophilicity of a surface. We extended such a feature to treating only local regions with plasma and used it to create micro-scale fluidic system on the surface of a chip. Instead of a traditional low-pressure plasma, which requires a vacuum chamber, an atmospheric-pressure plasma jet is utilized here. According to the results, the channel width of 533 μm was achieved by downsizing the jet nozzle to 600 μm. It is also found that the channel width is directly related to the duration of plasma treatment. To ensure the feasibility of the proposed method, the aging of surface hydrophilicity was investigated. Finally, an application of microfluidic mixing chip was fabricated using the proposed method.