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 μm channel width, a sample solution amount as small as 4.5 μL is sufficient to perform the test. NO₂ ^? assay is also performed and shows that such a device is capable for biochemical analysis.