Origami Microfluidics: A Review of Research Progress and Biomedical Applications

In recent years, origami/paper folding art has been applied to more and more scientific research due to the efficiently producing tiny structures at a low cost; inspired by this, origami microfluidics (the combination of origami/paper folding with paper-based microfluidics) has also been proposed. In origami microfluidic devices, three-dimensional fluid paths can be formed directly by folding the paper with pre-deposited hydrophobic barriers to accomplish complex fluid manipulation. Compared with the layer-by-layer approach, paper folding is more convenient and easier to fabricate three-dimensional microchannels and can meet the increasing requirements of microfluidic end users and improve the functionality of paper-based microdevices. This review is trying to introduce the most current developments of origami paper-based microfluidics, focusing on hydrophobic barrier processing, paper folding, and methods to fix the folded paper. By paper folding, the application prospects of paper-based microfluidics in the biomedical field have been expanded; thus, some biomedical applications of origami microfluidics are also briefly reviewed in this study. Finally, the challenges and perspectives of origami microfluidics were discussed in this review.