In-situ molding of micro three-dimensional columnar structure by electric-field-focused electrospinning

Abstract

An electric-field-focused electrospinning method was proposed to realize the in-situ molding of micro three-dimensional (3D) columnar structure. A grounded guide tip was utilized to generate a focused electric field to accelerate the charge transferring. The charged jet could be guided to deposited layer by layer into coil structure under the action of inner elastic stress. The dynamic evolution behavior of 3D columnar structures was performed. The distance between nozzle and collector was increased synchronously to establish the mechanical equilibrium between the electrical field force and the inner elastic stress. The mechanical equilibrium occurred when the jet stretching rate was equal to the fiber stacking rate. Lower stretching rate relaxed the jet and increased the diameter of 3D columnar structures. Larger stretching rate increased the inner stress and decreased the diameter of 3D columnar structures. Then, micro 3D columnar structures with diameter and height of 20 µm∼80 µm and 10 µm∼1.68 mm in different shapes including cylindrical, bowl, conical and porcelain bottle shape were realized.