@article{KadeTandonWeichholdetal.2021,
  author    = {Kade, Juliane C. and Tandon, Biranche and Weichhold, Jan and Pisignano, Dario and Persano, Luana and Luxenhofer, Robert and Dalton, Paul D.},
  title     = {Melt electrowriting of poly(vinylidene fluoride-co-trifluoroethylene)},
  series = {Polymer International},
  volume    = {70},
  journal   = {Polymer International},
  number    = {12},
  doi       = {10.1002/pi.6272},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-257654},
  pages     = {1725-1732},
  year      = {2021},
  abstract  = {Poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-co-TrFE)) is an electroactive polymer with growing interest for applications in biomedical materials and flexible electronics. In this study, a solvent-free additive manufacturing technique called melt electrowriting (MEW) has been utilized to fabricate well-defined microperiodic structures of the copolymer (P(VDF-co-TrFE)). MEW of the highly viscous polymer melt was initiated using a heated collector at temperatures above 120 °C and required remarkably slow collector speeds below 100 mm min\(^{-1}\). The fiber surface morphology was affected by the collector speed and an increase in β-phase was observed for scaffolds compared to the unprocessed powder. Videography shows vibrations of the P(VDF-co-TrFE) jet previously unseen during MEW, probably due to repeated charge buildup and discharge. Furthermore, piezo-force microscopy measurements demonstrated the electromechanical response of MEW-fabricated fibers. This research therefore achieves the melt electrohydrodynamic processing of fibers with micrometer resolution into defined structures with an important electroactive polymer.},
  language  = {en}
}
@article{KadeOttoLuxenhoferetal.2021,
  author    = {Kade, Juliane C. and Otto, Paul F. and Luxenhofer, Robert and Dalton, Paul D.},
  title     = {Melt electrowriting of poly(vinylidene difluoride) using a heated collector},
  series = {Polymers for Advanced Technologies},
  volume    = {32},
  journal   = {Polymers for Advanced Technologies},
  number    = {12},
  issn      = {1042-7147},
  doi       = {10.1002/pat.5463},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318493},
  pages     = {4951 -- 4955},
  year      = {2021},
  abstract  = {Previous research on the melt electrowriting (MEW) of poly(vinylidene difluoride) (PVDF) resulted in electroactive fibers, however, printing more than five layers is challenging. Here, we investigate the influence of a heated collector to adjust the solidification rate of the PVDF jet so that it adheres sufficiently to each layer. A collector temperature of 110°C is required to improve fiber processing, resulting in a total of 20 fiber layers. For higher temperatures and higher layers, an interesting phenomenon occurred, where the intersection points of the fibers coalesced into periodic spheres of diameter 206 ± 52 μm (26G, 150°C collector temperature, 2000 mm/min, 10 layers in x- and y-direction).The heated collector is an important component of a MEW printer that allows polymers with a high melting point to be processable with increased layers.},
  language  = {en}
}