Design and fabrication of self-powered flexible P(VDF-TrFE)/ZnO/TiO2 fiber mats as nanogenerator for wearable applications

Abstract

Polymer-based nanocomposite fibrous membranes are the basis of wearable flexible devices, but the application of high voltage poling, brittle material as dopants, or toxic compounds is the main challenge in the development of such devices. P(VDF-TrFE)/ZnO/TiO2 electrospun nanofiber mats are used in here to fabricate self-poled, lead-free, and flexible piezoelectric nanogenerators. Herein, self-poled, lead free, and flexible high performance piezoelectric nanogenerators (PENGs) are designed using the P(VDF-TrFE)/ZnO/TiO2 electrospun fiber mats. Three phase nanocomposite mats with varying TiO2 concentrations are fabricated using far-field electrospinning method. In this study, we reported the effect of ZnO and TiO2 nanoparticles on the viscoelastic property and piezoelectric output. The electroactive beta (β) phase fraction of P(VDF-TrFE) mats are observed to be enhanced as a result of the dispersion of TiO2 nanoparticles into the three phase nanocomposite films. The dielectric and viscoelastic properties are improved with the addition of TiO2 nanoparticles. The designed piezoelectric device produced short circuit current, open circuit voltage, and piezoelectric peak power of 4.16 μA, 23 V, and 95.68 μW, respectively. These piezoelectric outputs are obtained with the optimization of TiO2 concentration and the PENG devices are subjected to elbow bending, wrist bending, and finger tapping. The piezoelectric output of three phase composite mats is almost 3.6 times higher than PENG made from P(VDF-TrFE) fiber, and the increment in the performance is due to the synergistic effect of ZnO and TiO2 in the P(VDF-TrFE) polymer matrix. PENG is used to display real-time demonstrations of body movement detection and biomechanical energy harvesting to power an LED bulb. The enhanced performance and robustness of the nanogenerator make the electrospun P(VDF-TrFE)/ZnO/TiO2 mat an excellent candidates for sensing and energy harvesting applications.