fig1

Figure 1. (A) Schematic illustration of preparation process, microstructure and surface charge distribution of HPFs. Cross-sectional SEM images of (B) HPFs and (C) SPFs. Side-view SEM images of (D) HPFs and (E) SPFs. HPF: Hollow poly(3,4-ethylenedioxythiophene):polystyrene sulfonate thin-walled fibers; SPF: solid PEDOT:PSS fibers; SEM: scanning electron microscopy.