Additive manufacturing of single- and double-layer piezoelectric PVDF-TrFE copolymer sensors

The sensitivity of piezoelectric PVDF sensors is directly related to the concertation and orientation of the polar phases. Previous efforts in obtaining oriented polar phases during 3D printing proved to be challenging. In this paper the superiority of the copolymer PVDF-TrFE when compared to PVDF for 3D printing is demonstrated. In contrast to PVDF, PVDF-TrFE forms nearly pure beta-phase in solidification from melt. The emergence of more beta-phase than the non-polar alpha-phase is demonstrated with XRD results. 3D printed double-layer samples were produced consisting of one electroactive layer of PVDF-TrFE, and a non-electroactive substrate and protective layer of PVDF. The 3D printed samples were poled with corona discharge to produce output signals up to 130V(DC) peak-to-peak from a simple impact test (flicking) on a 20X30 mm sample. We also observed high sensitivity to 2mm dynamic displacement loads that produced similar to 19V. The results presented here are considerably higher than any reported results from other additive manufacturing methods. (C) 2019 The Authors. Published by Elsevier B.V.