Moldable Perfluoropolyether–Polyethylene Glycol Networks with Tunable Wettability and Solvent Resistance for Rapid Prototyping of Droplet Microfluidics

Soft lithography-based droplet microfluidics has enabled production of highly uniform and complex emulsions. Although there is a significant potential to use these emulsions as templates for functional materials syntheses, conventional elastomers that are used for microfluidic device preparation are significantly deformed and swollen by various organic solvents, limiting the types of materials that can be processed using conventional soft lithography-based droplet microfluidics. In this report, we demonstrate that both water-in-oil and oil-in-water emulsion with organic solvents can be produced by using microfluidic devices that are prepared using cross-linked networks of perfluoropolyether (PFPE) and poly(ethylene glycol) diacrylate (PEGDA). We show that these PFPE–PEG networks are transparent and maintain excellent compatibility with various organic solvents. Importantly, the wettability of these devices can be systematically controlled by changing the ratio of the two macromonomers. By taking advantage...