From Single-Nozzle to Multi-Nozzle Electrospinning: A Comparative Manufacturability Perspective on 3D Electrospun Structures

Electrospinning has evolved from producing two-dimensional nanofiber mats to forming three-dimensional electrospun (3D ES) structures with improved mechanical integrity and functional performance. However, scalable and controllable fabrication of 3D ES structures remains challenging. This review provides a quantitative and mechanism-oriented comparison of major fabrication strategies, including single-nozzle electrospinning (SN), electric field manipulation (EFM), mold-based methods (MBM), near-field electrospinning (NF), hybrid electrospinning–3D printing methods (HBM), controlled deposition systems (CDM), and multi-nozzle electrospinning (MN). Reported operating parameters span applied voltages from 0.1 to 65 kV, working distances from 0.1 to 385 mm, and material delivery rates from 0.006 to 96 mL/h. SN-based and mold-assisted approaches demonstrate the feasibility of forming 3D ES structures under single-jet conditions and low flow rates (typically < 7 mL/h), but their scalability is inherently limited. NF achieves high positional accuracy at short working distances (≤ 80 mm) and low voltages (≤ 8 kV), though its narrow process window restricts large-area fabrication. In contrast, MN electrospinning enables the highest throughput, with nozzle counts ranging from 2 to 72 and fiber diameters as small as 66 nm. Importantly, successful 3D structure formation using single-nozzle configurations confirms that the fundamental electrohydrodynamic mechanisms for three-dimensional growth already exist, implying that MN systems operating at higher throughput possess greater potential for scalable 3D ES fabrication. Despite this, MN performance remains highly sensitive to inter-nozzle spacing, electric-field uniformity, and jet–jet electrostatic interactions, which continue to limit deposition uniformity and mechanical robustness.