Hybrid Pizo-Triboelectric Energy Nanogenerator from Woollen fabric and PVDF/BaTiO3 Nanofibrous Layer

Harvesting of wasted energies using mechanical to electrical energy nanogenerators has become a major branch of energy research area due to the global energy concerns. Piezoelectric and triboelectric mechanisms are between the two most widely used methods in this field. In this study, different combinations of fibrous nanogenerators including PVDF nanofibers and PVDF / BaTiO3 composite nanofibers with wool fabrics consist of three types of weft knitted fabric and combed wool fibers were prepared, due to their promising position in the triboelectric series. Different configuration of layers were also set to optimize the layer composition for the best electrical output. The electrical output voltage per unit area of different samples were measured after the contact - separation mode of electrification for each sample. Results showed that the arc-shape layer deposition has the best triboelectric layer arrangement to achieve the optimized electrical output at a specified force with the highest output value of 4.35(V/cm2), where the output of PVDF piezoelectric layer was only 0.475(mV/cm2). For a given force, the output of the triboelectric nanogenerator was more than 9000 times higher than that of the pure PVDF/BaTiO3 piezoelectric nanogenerator. These results teach us a first step towards the fabrication of self-chargeable wearable microelectronic devices.