Wearable Piezoelectric Nanogenerators Based on Core–Shell Ga-PZT@GaO_x Nanorod-Enabled P(VDF-TrFE) Composites

Abstract

High-output flexible piezoelectric nanogenerators (PENGs) have achieved great progress and are promising applications for harvesting mechanical energy and supplying power to flexible electronics. In this work, unique core–shell structured Ga-PbZr x Ti1–x O3 (PZT)@GaO x nanorods were synthesized by a simple mechanical mixing method and then were applied as fillers in a poly­(vinylidene fluoride–trifluoroethylene) (P­(VDF-TrFE)) matrix to obtain highly efficient PENGs with excellent energy-harvesting properties. The decoration of gallium nanoparticles on PZT @GaO x nanorods can amplify the local electric field, facilitate the increment of polar β-phase fraction in P­(VDF-TrFE), and strengthen the polarizability of PZT and P­(VDF-TrFE). The interfacial interactions of GaO x and P­(VDF-TrFE) are also in favor of an increased β-phase fraction, which results in a remarkable improvement of PENG performance. The optimized Ga-PZT@GaO x /P­(VDF-TrFE) PENG delivers a maximum open-circuit voltage of 98.6 V and a short-circuit current of 0.3 μA with 9.8 μW instantaneous power under a vertical force of 12 N at a frequency of 30 Hz. Such a PENG exhibits a stable output voltage after 6 000 cycles by the durability test. Moreover, the liquid gallium metal offers a mechanical matching interface between rigid PZT and the soft polymer matrix, which benefits the effective, durable mechanical energy-harvesting capability from the physical activities of elbow joint bending and walking. This research renders a deep association between a liquid metal and piezoelectric ceramics in the field of piezoelectric energy conversion, offering a promising approach toward self-powered smart wearable devices.

Flexible PVDF–TrFE Nanocomposites with Ag-decorated BCZT Heterostructures for Piezoelectric Nanogenerator Applications

“…As shown in Figure a,b, the maximum electric field strength of the pure BCZT NWs/PVDF–TrFE composite film was 9.51 × 10 8 V/m, and after the introduction of a conductor, the maximum electric field strength reached 7.04 × 10 9 V/m after the decoration of Ag nanoparticles, which is 6.4 times higher than that of pure BCZT NWs/PVDF–TrFE composite film. This demonstrates that the decoration of Ag nanoparticles on BCZT NWs is beneficial to the polarization of the composite films due the existence of electric field concentrations . Moreover, the piezoelectric potential generated by Ag-BCZT NWs/PVDF–TrFE composite film is higher than that of pure BCZT NWs/PVDF–TrFE composite film under the same mechanical stress; see Figure c,d.…”

“…This demonstrates that the decoration of Ag nanoparticles on BCZT NWs is beneficial to the polarization of the composite films due the existence of electric field concentrations. 52 Moreover, the piezoelectric potential generated by Ag-BCZT NWs/PVDF−TrFE composite film is higher than that of pure BCZT NWs/PVDF−TrFE composite film under the same mechanical stress; see Figure 8c,d. The simulation results of electric field distribution and piezoelectric potential indicate that the decoration of Ag nanoparticles aids the polarization and output performance of BCZT NWs/PVDF−TrFE composite films.…”

Enhancing the Piezoelectric Sensing of CFO@PDA/P(VDF-TrFE) Composite Films through Magnetic Field Orientation

“…According to the Beer–Lambert law, , the amount of β-phase ( F (β)) can be calculated by using the following eq : where A α and A β correspond to the absorption coefficients at 763 and 837 cm –1 and K α (6.1 × 10 4 cm 2 /mol) and K β (7.7 × 10 4 cm 2 /mol) are the absorption coefficients at the respective wavenumber. Figure e gives the calculated values F (β) of CFO@PDA/P­(VDF-TrFE) composite films heat cured without magnetic field.…”

Synergistic Effect of Polyurethane in Polyurethane–Poly(vinylidene fluoride) Nanofiber-Based Stretchable Piezoelectric Nanogenerators (S-PENGs)

“…3 We can efficiently utilize human movements as an input to generate mechanical deformation to produce electrical output in PENGs. 4 However, for the efficient use of human kinetic as an input, the PENG-based intelligent devices should be integrated with wearables to extract energy during the movement of the various parts of the body. For this, the flexibility and durability of PENG-based devices are critical prerequisites.…”