Enhanced Piezoelectricity of Nanoimprinted Sub-20 nm Poly(vinylidene fluoride–trifluoroethylene) Copolymer Nanograss

Abstract

In this paper, sub-20 nm ferroelectric PVDF–TrFE copolymer nanograss structures with aspect ratios up to 8.9 were developed. This study demonstrated sub-20 nm PVDF–TrFE nanograss structures that are nanoimprinted using a silicon nanograss mold in a single step. Vertically oriented PVDF–TrFE nanopillars were poled using the developed flip-stacking poling method. According to the PFM measurements, the piezoelectricity of flat thin films fabricated in this work reaches 14.0 pm/V. The maximum output voltage of the single PVDF–TrFE nanopillar was 526 mV, and the maximum piezoelectricity of the single PVDF–TrFE nanopillar was 210.4 pm/V. The piezoelectricity of the developed PVDF–TrFE nanograss structures was 5.19 times larger than that of the PVDF–TrFE flat thin films. The developed technique is simple, economical, and easy to fabricate. The developed ferroelectric PVDF–TrFE copolymer nanograss structures, which showed enhanced piezoelectricity compared to the PVDF–TrFE flat thin films, have potential applications in nanotip-based protein biosensors, nanotip-based tactile sensors, and power nanogenerators.

Impact of crystallization on ferro-, piezo- and pyro-electric characteristics in thin film P(VDF–TrFE)

“…Moreover, a high piezoelectric coefficient of À72 pC/N for P(VDF-TrFe) nanowires was reported by Hong et al [24], this can be explained by the relationship between the thickness and the crystallization. A very weak vertical displacement was obtained with the unpoled device which highlights the necessity to initially pole the P(VDF-TrFe) film in order to initiate the piezoelectric effect in the device by aligning the dipoles.…”

Nanostructured polymer-based piezoelectric and triboelectric materials and devices for energy harvesting applications

“…Co-polymers of PVDF where some of the hydrogen atoms are replaced with fluorine atoms are more likely to crystallise in a polar phase due to steric factors. Even then, it has been reported that electrically poled P(VDF-TrFE) nanowire arrays could have over 10 times higher piezoelectric coefficients than normal P(VDF-TrFE) thin films undergoing the same treatment [25]. More recently, nanowire synthesis approaches making use of a nanoconfinement growth effect have been found to be more likely to result in so-called 'selfpoled' β phase NWs [21,26], mostly observed, for example, in template-assisted growth whereby polymer NWs are grown within nanoporous templates by infiltration from solution or melt, and where the resulting NWs do not require external electrical poling in order to exhibit piezoelectric behaviour.…”

Soft biomimetic tapered nanostructures for large-area antireflective surfaces and SERS sensing

“…[27][28][29][30] In order to produce polymer nanostructures, hot embossing through a mold is applied in the pre-mentioned fabrication techniques. During the hot embossing procedure, the system is heated above the glass transition temperature of the polymer and a desired pressure is applied.…”