Comparative analysis of fiber alignment methods in electrospinning

Fabrication of anisotropic materials is highly desirable in designing biomaterials and tissue-engineered constructs. Electrospinning has been broadly adopted due to its versatility in producing non-woven fibrous meshes with tunable fiber diameters (from 10 nm to 10 μm), microarchitectures, and construct geometries. A myriad of approaches has been utilized to control fiber alignment of electrospun materials to achieve complex microarchitectures, improve mechanical properties, and provide topographical cellular cues. This review provides a comparative analysis of the techniques developed to generate fiber alignment in electrospun materials. A description of the underlying mechanisms that drive fiber alignment, setup variations for each technique, and the resulting impact on the aligned microarchitecture is provided. A critical analysis of the advantages and limitations of each approach is provided to guide researchers in method selection. Finally, future perspectives of advanced electrospinning methodologies are discussed in terms of developing a scalable method with precise control of microarchitecture. Electrospinning is a widely used technique for the fabrication of non-woven fibrous materials. Methods to induce electrospun fiber alignment provide researchers with new tools to guide cellular behavior, expand mechanical properties, and improve a variety of physical properties. This comparative analysis provides a detailed description of popular methods to generate fiber alignment and mesh anisotropy. A discussion of the advantages, disadvantages, and setup variations is provided for each method to guide researchers on method selection for a given application. Although significant progress has been made to advance electrospinning processes, there remains a need for continued improvements to address reproducibility, inhomogeneity of microarchitecture, and scalability of meshes in both size and production rate. Overall, the versatility and expanding control of microarchitecture has secured a growing role for aligned electrospinning methods in advanced manufacturing of medical devices. Aligned electrospinning methods provide researchers with new tools to achieve complex microarchitectures, improved mechanical properties, and topographical cellular cues. This review provides a comparative analysis of techniques to generate fiber alignment in electrospun materials with a discussion of advantages and limitations of each setup to guide method selection.