variable speed electric motor (Amtek, Monrovia, CA). The spinneret was connected to a direct current (DC) voltage power supply (HV350, Unlimited, Amherst, NH) and centered in a non-conductive cylindrical housing with a diameter that could be varied from 2 to 4 ft. A grounded collector (diameter: 45.7 cm) was secured to the non-conductive housing, concentrically surrounding the central hub. The gap between the electrodes was 5.1 cm. The BaTiO3–PVDF solution was electrospun in a 20-gauge (inner diameter: 0.60 mm), 451 bent needle at a DC voltage of 8 kV, and the distance from the spinneret to the collector was 22 cm. Each solution was electrospun with the spinneret rotating at a speed of 162 rpm. The electrospun nanofibers (length: 5 cm) were collected into fibrous bundles (thickness: 2 mm) from the gap between the electrodes of the electrospinning system.