One-step rapid fabrication of paper-based microfluidic devices using fluorocarbon plasma polymerization

In this work, we demonstrated an all-dry, top-down, and one-step rapid process to fabricate paper-based microfluidic devices using fluorocarbon plasma polymerization. This process is able to create fluorocarbon-coated hydrophobic patterns on filter paper substrates while maintaining the trench and detection regions intact and free of contamination after the fabrication process, as confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. We have shown that the processing time is one critical factor that influences the device performance. For the device fabricated with a sufficiently long processing time (180 s), the sample fluid flow can be well confined in the patterned trenches. By testing the device with an 800 mu m channel width, a sample solution amount as small as 4.5 mu L is sufficient to perform the test. NO2 (-) assay is also performed and shows that such a device is capable for biochemical analysis.