Frontiers in Bioinspired Polymer-Based Helical Nanofibers from Electrospinning.

Helices are among the most significant structures in nature, representing an emerging group of materials distinguished by their unique helical geometry. Recently, helical nanofibers have attracted considerable attention due to their exceptional structural characteristics and versatile applications in various fields, including tissue engineering, biomedicine, nanotechnology, and chiral materials. Therefore, developing methods to fabricate biomimetic helical fibers on demand, which can exhibit a diverse range of physical properties and forms, is of great interest across multiple disciplines. Despite the significant interest in helical fibrous materials, the fabrication of such complex structures at the micro- or nanoscale level remains a major challenge. Electrospinning offers a simple and versatile technique for producing micro- and nanofibers in various helical shapes. This review systematically summarizes and classifies the state-of-the-art advancements in electrospun helical nanofibers into four categories based on their forming mechanisms: viscoelastic asymmetric contraction, bending instability motion, jet-induced buckling response, and rotary winding molding. Additionally, the recent applications of these helical nanofibrous materials in areas such as environmental remediation, interactive textiles, and biomedical engineering are also summarized. Furthermore, the current challenges and future perspectives in the field are put forward. We anticipate that the insights provided will contribute to the rational design of advanced artificial helical materials, thereby enhancing their practical applications in the future.