2.2. Electrospinning Setup with Cylindrical Dielectric Guides

The cylindrical dielectric guide in the electrospinning system was made of polylactic acid (PLA) using a fuse deposition modeling method 3D printer (CUBICON Single Plus, Cubicon, Seongnam, Korea). By using a lamination method 3D printing is made economical and it has a high degree of freedom in manufacturing shapes. In this study, cylinder structures of various sizes were fabricated with a 3D printer to concentrate the electric field. The cylinder structure is symmetrical in the axial direction and can generate a uniform electric field.

In addition, PLA was selected as the material for producing the cylindrical dielectric guide. PLA is widely used as a material for 3D printing due to its good formability and low shrinkage of the product. Cylindrical dielectric guides were manufactured with diameters (D_guide) ranging from 30 to 120 mm. Each mixed solution was loaded into a 3-mL syringe with a 21-gage needle for electrospinning. The syringe was placed in a syringe pump (Legato 100 syringe pump, KD Scientific, Holliston, MA, USA), and the solution was pulled out at a rate of 1 mL/h from the needle tip. The tip of the syringe was connected to the positive electrode of a high-voltage power supply (ERP series, Matsusada Precision, Kusatsu, Japan). Each mixed solution was electrospun onto an aluminum plate located 75 mm from the needle tip. The cylindrical dielectric guide was located at the center of the syringe tip.