The Radial Piezoelectric Response from Three-Dimensional Electrospun PVDF Micro Wall Structure

Abstract

The ability of electrospun polyvinylidene fluoride (PVDF) fibers to produce piezoelectricity has been demonstrated for a while. Widespread applications of electrospun PVDF as an energy conversion material, however, have not materialized due to the random arrangement of fibers fabricated by traditional electrospinning. In this work, a developed 3D electrospinning technique is utilized to fabricate a PVDF micro wall made up of densely stacked fibers in a fiber-by-fiber manner. Results from X-ray diffraction (XRD) and Fourier transform infrared spectra (FTIR) demonstrate that the crystalline structure of this PVDF wall is predominant in the β phase, revealing the advanced integration capability of structural fabrication and piezoelectric poling with this 3D electrospinning. The piezoelectric response along the radial direction of these PVDF fibers is measured while the toppled micro wall, comprised of 60 fibers, is sandwich assembled with a pair of top/bottom electrodes. The measured electrical output is ca. 0.48 V and 2.7 nA. Moreover, after constant mechanical compression happening over 10,000 times, no obvious reduction in the piezoelectric response has been observed. The combined merits of high-precision 3D fabrication, in situ piezoelectric poling, and high mechanical robust make this novel structure an attractive candidate for applications in piezoelectric energy harvesting and sensing.

Electrospun PVDF Nanofibers for Piezoelectric Applications: A Review of the Influence of Electrospinning Parameters on the β Phase and Crystallinity Enhancement

“…Viscosity plays an important role in the process of electrospinning; therefore, it is necessary to select PVDF with a suitable molecular weight for electrospinning experiments. The more commonly used molecular weights are 275,000 and 534,000 g·mol −1 [ 73 , 74 , 78 , 95 , 99 , 106 , 107 , 108 , 109 , 110 , 111 ].…”

Electrical Detection of Vibrations of Electrospun PVDF Membranes

“…Without this phenomenon, any piezoelectric effect could not exist for the membrane made of randomly arranged fibres. Here the electric dipoles randomly oscillate and the total spontaneous polarization from the electric dipoles is constant and without the mechanical stimulus, no output current or voltage can be observed [13]. So, when the anode is connected to the upper side of the membrane, a positive piezoelectric signal is generated during compression (Figure 3c; blue curves).…”

Piezoelectric Response and Substrate Effect of ZnO Nanowires for Mechanical Energy Harvesting in Internet-of-Things Applications

“…In recent years, focused research effort has been directed toward components fabricated on flexible substrates [ 58 , 64 , 65 , 66 ] that greatly expand the possible range of applications served by EH components. The current research is in line with this trend.…”