Flexible Microfluidic Fabrication of Anisotropic Polymer Microfibers

This article describes a microfluidic method for fabricating anisotropic polymer microfibers. Janus colaminar flows were realized in a microfluidic device. Microfibers with a noncircular cross-section were fabricated by an in situ photopolymerization method. The microflows experienced different evolutionary states in the micro channel. Simple control of the curing time resulted in the microfibers forming different shapes. The morphology of the cross-section could be readily manipulated by the interfacial tensions and flow rates of the fluids. Theoretical analysis and computational fluid dynamics simulation were used to predict the effect of these factors on the fiber morphology. The theoretical and simulation results were in good agreement with the experimental results. Microfibers with nonuniform surface properties could also be produced by adding modification reagents into the different fluids. The selective coating of micro/nanoparticles on the convex or concave surfaces of the microfibers was realized.