Table 2.

Advantages and limitations of different fabrication techniques for paper-based microfluidic devices.

Fabrication methods	Advantages	Limitations
Photolithography [46,47]	High resolution of channel with sharp barriers, suitable for large-scale production	Requires expensive instruments and reagents, involves complex steps, fragile while bending
Inkjet printing [28,48]	Able to rapidly fabricate devices on a large scale	Requires a customized inkjet printer and an extra heating step for curing purposes
PDMS plotting [43,45]	Inexpensive technique to fabricate flexible devices	Low resolution, demands modification of the plotter, inconsistent control over the penetration of PDMS due to the nonuniform porous nature of paper
Laser cutting [2,3,16,49–53]	Simple and inexpensive technique to cut specific patterns and assemble devices	Requires a laser cutter/engraver, graphics software, and DSA
Laser printing [54]	Simple and inexpensive method to fabricate microfluidic devices	Requires laser printer, graphics software, laminator, and paper driller
Wax printing [19]	Fast and simple fabrication technique, suitable for mass production	Low resolution, uses expensive wax printer, not resistant to high temperatures
Wax dipping [43,55]	Simple and fast fabrication technique with better reproducibility, suitable for mass production	Low resolution, heating requirement
Screen printing [56]	Cost-effective and simple process, well-suited for mass production	Low resolution, each pattern requires an individual screen
Plasma treatment [45,48]	Inexpensive process, the flexibility of paper is maintained	Each pattern requires a specific photomask
Flexographic printing [19,47,57]	Enables fast, commercial roll-to-roll production of paper-based microfluidic devices	Multi-step process that requires complex reagents, and specialized commercial printers, requires frequent cleaning to avoid contamination, roughness of the paper substrate affects the final quality of printing