Effects of Substrate on Piezoelectricity of Electrospun Poly(vinylidene fluoride)-Nanofiber-Based Energy Generators

Abstract

We report the effects of various substrates and substrate thicknesses on electrospun poly(vinylidene fluoride) (PVDF)-nanofiber-based energy harvesters. The electrospun PVDF nanofibers showed an average diameter of 84.6 ± 23.5 nm. A high relative β-phase fraction (85.2%) was achieved by applying high voltage during electrospinning. The prepared PVDF nanofibers thus generated considerable piezoelectric potential in accordance with the sound-driven mechanical vibrations of the substrates. Slide glass, poly(ethylene terephthalate), poly(ethylene naphthalate), and paper substrates were used to investigate the effects of the intrinsic and extrinsic substrate properties on the piezoelectricity of the energy harvesters. The thinnest paper substrate (66 μm) with a moderate Young's modulus showed the highest voltage output (0.4885 V). We used high-performance 76, 66, and 33 μm thick papers to determine the effect of paper thickness on the output voltage. The thinnest paper substrate resulted in the highest voltage output (0.7781 V), and the numerical analyses of the sound-driven mechanical deformation strongly support the hypothesis that substrate thickness has a considerable effect on piezoelectric performance.

Wearable piezoelectric device assembled by one-step continuous electrospinning

“…Thus using continuous electrospinning method to construct multilayer device shows superiority than previous method by assembling different membranes together. 7 Porous structures of membranes confirmed by SEM implies their good air permeability. To test the air permeability of them, pressure difference of 300 Pa was involved on the membranes.…”

“…Recently, piezoelectric generator which could convert waste energy from the ambient environment and human activity to electric energy was investigated. [4][5][6][7][8] This invention provides a new routine for powering portable electronic devices with low-energy consumption. Wang et al involved inorganic piezoelectric nanowires into piezoelectric generator in 2006 implied the great potential of piezoelectric materials in energy harvesting.…”

“…PVDF and its copolymers are the mostly studied organic piezoelectric materials for high piezoelectricity. [5][6][7][8] Tremendous efforts have been paid to induce electroactive β-phase crystalline in PVDF, and a variety of strategies have been proposed for fabricating polymeric piezoelectric devices. Kim et al introduced a piezoelectric generator of good machinability and mechanical flexibility by casting poly(vinylidene fluoride trifluoroethylene) [P(VDF-TrFE)] solution onto mobilitymodified chemical vapor deposition-grown graphene electrode.…”

“…19,20 Nan et al and our group sandwiched randomly oriented PVDF nanofiber membranes and aligned P(VDF-TrFE) nanofiber membranes between two planar electrodes to build vibrationdriven piezoelectric devices. 5,7 The assembled piezoelectric devices produced high output were applied to mechanical generator and sensor. However, these reported piezoelectric devices were mostly made of gas-proof electrodes, for example graphene film, conductive sheet of indium tin oxide deposited on polyethylene terephthalate film (ITO/PET), evaporated metallic film, etc.…”

Mechanical Energy‐to‐Electricity Conversion of Electron/Hole‐Transfer Agent‐Doped Poly(Vinylidene Fluoride) Nanofiber Webs

“…Various mechanical‐to‐electrical energy conversion devices have been developed using the principles such as electromagnetic, piezoelectric, or triboelectric . Piezoelectric materials, especially piezoelectric polymers, e.g., poly(vinylidene fluoride) (PVDF) and its copolymers, offer advantages in developing flexible devices with high strain level and stability …”