Fig. 2
Reproduced with permission from Ref. [21]
Fibers with multifarious morphologies prepared by electrospinning. a–d Different NF assembly morphologies: a random oriented, b aligned as well as (c) patterned and (d) spider-web-like nano-fiber/net structures. e–q Various single NFs with (e) bead-on-string, (f) ribbon-like, (g) helical, (h) porous [30], (i) necklace-like, (j) firecracker-shaped, (k) rice grain-shaped, (l) core—shell, (m) multichannel tubular, (n) multi-core cable-like, (o) tube-in-tube, (p) nanowire-in-microtube and (q) hollow structures.