Improved Size Uniformity of Microcapillaries in Microcapillary Films by Separate Gas Injection

Abstract Microcapillary films (MCFs) are microextrusion‐processed plastic films containing an array of parallel microcapillaries, and have been widely utilized as microfluidic platforms. However, the nonuniform size distribution within a single MCF strip limits the application of MCFs in monodisperse droplet generation. In this paper, the mechanisms that lead to uneven microcapillary dimensions in conventional MCFs whose gas pressures in all channels are the same is first clarified. The effect of gas pressure in a single channel on the microcapillary dimensions in the film is then studied. Finally, the size uniformity of the microcapillaries is improved by separate gas injection in different channels, providing new possibilities for the generation of highly monodisperse microdroplets.