Enhanced Piezoelectric Energy Harvesting Performance of Flexible PVDF-TrFE Bilayer Films with Graphene Oxide

Abstract

Ferroelectric materials have attracted interest in recent years due to their application in energy harvesting owing to its piezoelectric nature. Ferroelectric polymers are flexible and can sustain larger strains compared to inorganic counterparts, making them attractive for harvesting energy from mechanical vibrations. Herein, we report, for the first time, the enhanced piezoelectric energy harvesting performance of the bilayer films of poled poly(vinylidene fluoride-trifluoroethylene) [PVDF-TrFE] and graphene oxide (GO). The bilayer film exhibits superior energy harvesting performance with a voltage output of 4 V and power output of 4.41 μWcm(-2) compared to poled PVDF-TrFE films alone (voltage output of 1.9 V and power output of 1.77 μWcm(-2)). The enhanced voltage and power output in the presence of GO film is due to the combined effect of electrostatic contribution from graphene oxide, residual tensile stress, enhanced Young's modulus of the bilayer films, and the presence of space charge at the interface of the PVDF-TrFE and GO films, arising from the uncompensated polarization of PVDF-TrFE. Higher Young's modulus and dielectric constant of GO led to the efficient transfer of mechanical and electrical energy.

Stretchable quaternary phasic PVDF-HFP nanocomposite films containing graphene-titania-SrTiO3 for mechanical energy harvesting

“…Energy harvesting materials and devices based on flexible polymer nanocomposites have significant attention in recent times, due to their ability to convert mechanical vibrations to electrical energy [23]. The harvested electric power density of 464 and 561% respectively were reported for the neat PVDF-HFP films using ac and dc circuits [24].…”

P(VDF-TrFE) Film on PDMS Substrate for Energy Harvesting Applications

“…The maximum stored energy and average power values were determined to be 113.74 µJ and 370 nW, respectively. Based on the active area and thickness of the sample (4 cm 2 and 7 × 10 −4 cm), the maximum output power density can be calculated as 6.62 mW/cm 3 , which is comparable to the state-of-the-art performance across all energy harvesting device technologies [5,15,[19][20][21][22][23][24][31][32][33][34][35][36][37][38]. Although the power from the device is in the sub µW range, just a single device can still provide sufficient power to operate structural health monitoring devices, such as a 100 nW temperature sensor, or a low-power 4 kB 80 nW microprocessor [39][40][41].…”

“…Wang et al [20] fabricated patterned PDMS-MWCNT composite-based P(VDF-TrFE) (85 µm thick) hybrid NG, and piezoelectric output voltage was 2.5 V. Micropatterned (pyramid-shaped) P(VDF-TrFE) piezoelectric-pyroelectric NG (7 µm thick) on the CNT/PDMS composite substrate demonstrated by Lee et al [19] led to an output voltage of only 1.4 V. By comparison, our device provides a significantly better performance, while requiring a much simpler fabrication process. Table 1 compares the output performance of the current device with various PVDF and P(VDF-TrFE) based NG reported earlier [15,[19][20][21][22][23][24].…”

“…Ding et al [22] developed PDMS/polyethylene terephthalate (PET)-based PVDF (active material, 5 µm) energy harvester, and the demonstrated output voltage and current were 150 mV and 4 nA, respectively. The output performance PVDF and P(VDF-TrFE) energy harvesters are shown in Table 1 [15,[19][20][21][22][23][24]. In spite of their promise, PDMS-based composites (with other materials, such as CNT) or patterned structures, as reported earlier, pose several challenges, including complicated fabrication processes, low reproducibility, non-uniform output, difficulty in interfacing with active layers like the P(VDF-TrFE) matrix, and degradation of structures over long-term usage in strong vibrational environments.…”

Self-powered graphene thermistor

“…P(VDF-TrFE) is a well-known ferroelectric polymer with higher remnant polarization charge and chemically inert under ambient conditions [14][15][16][17][18]. Because of the higher remnant polarization charge ( $ 8 μC/cm 2 ) of P(VDF-TrFE), it can introduce a large non-volatile doping in graphene [14,19].…”