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.