Frog tongue-inspired wettable microfibers for particles capture

Fibers have been of great significance in our daily lives, especially in the industrial production of masks. Research in this area has been focused on developing microfibers with superior functions to enhance the filtration performances of the masks. Herein, inspired by the frog's predation mechanism using its tongues to swiftly grab flying insects, we propose novel porous wettable microfibers from microfluidics to efficiently capture particles in the air for filtration. Upon pre-dispersing LP emulsions into polyurethane (PU), porous microfibers dispersed with oil droplets could be continuously spun from a co-flow microfluidic device based on the quick phase inversion of PU. To design an optimal system with frog-tongue-like interfacial adhesion properties, the wettability performances of the porous microfibers are investigated under full, partial, and no oil coverage conditions. When implemented in a mask, the 3D patterned networks based on the frog-tongue-inspired microfibers have been proven with remarkable particle capture performances while maintaining good air permeability. Based on these features, we believe that frog-tongue-inspired microfibers and their derived masks are of practical significance in multiple applications.