Additional file 1: Figure S1. of Self-Powered Active Sensor with Concentric Topography of Piezoelectric Fibers

Schematic of the experiment layout. The demonstrated GPFG was fixed at one end. The output voltage and current were generated via a rotating rod which driven by a commercial DC motor (RS-545SH). The induced strain can be altered by adjusting the contact position, and the actuating frequency can be easily tuned by the DC motor speed. Figure S2. Two PGCTs were superimposed to enhance the output voltages which. PGCT #A and PGCT #B subject to continuous stretch and release. Constructively, output voltages were basically added when two PGCT are in serial connection. All measurement data are performed when the two PGCTs operated in the same strain, strain rate, and frequency. Figure S3. XRD patterns of original PVDF powder (blue line), NFES PVDF fiber (red line) and conventional electrospinning PVDF thin film (green line). Figure S4. FTIR spectra of the PVDF powder and electrospinning PVDF fibers. The polymer solution 16 wt% PVDF, solvent (DMF:acetone with 1:1 weight ratio), 4 wt% fluorosufactant (Capstone® FS-66) was used for the electrospinning experiment. (PDF 357 kb)