@article{ZhongFuShanShanJiaQianetal.2003,
  author    = {Zhong-Fu, X. and Shan-Shan, M. and Jia-Qian, Z. and Xun-Lin, Q. and Ye-Wen, Z. and Gerhard, Reimund and K{\"u}nstler, Wolfgang},
  title     = {Piezoelectric activity and its stability of polytetrafluoroethylene (PTFE) films},
  year      = {2003},
  language  = {en}
}
@article{YilmazWirgesBauerGogoneaetal.1997,
  author    = {Yilmaz, S{\"u}kr{\"u} and Wirges, Werner and Bauer-Gogonea, Simona and Bauer, Siegfried and Gerhard, Reimund and Michelotti, F. and Toussaere, E. and Levenson, R. and Liang, J. and Zyss, Joseph},
  title     = {Dielectric, pyroelectric and electro-optic monitoring of the cross-linking process and photo-induced poling of Red Acid Magly},
  year      = {1997},
  language  = {en}
}
@article{XiaGerhardKuenstleretal.1999,
  author    = {Xia, Zhongfu and Gerhard, Reimund and K{\"u}nstler, Wolfgang and Wedel, Armin and Danz, Rudi},
  title     = {High surface-charge stability of porous polytetrafluoroethylene electret films at room and elvated temperatures},
  year      = {1999},
  language  = {en}
}
@article{WirgesWegenerVoroninaetal.2007,
  author    = {Wirges, Werner and Wegener, Michael and Voronina, Olena and Zirkel, Larissa and Gerhard, Reimund},
  title     = {Optimized preparation of elastically soft, highly piezoelectric, cellular ferroelectrets from nonvoided poly(ethylene terephthalate) films},
  doi       = {10.1002/adfm.200600162},
  year      = {2007},
  abstract  = {Electrically charged cellular polymer films can exhibit very high piezoelectric activity and are therefore more and more often employed in advanced electromechanical and electro-acoustical transducers. In this paper, we report an optimized sequence of steps for preparing such ferroelectrets from commercial nonvoided ploy(ethylene terephthalate) (PETP) films by means of foaming with CO2 biaxial mechanical stretching, controlled void inflation, and bipolar electric charging. The nonvoid PETP films foamed with supercritical CO2 at a suitably high pressure and subsequently annealed for stabilization. The cellular foam structure was further optimized by means of well controlled biaxial stretching in a commercial stretcher and sometimes subsequent inflamation in a pressure chamber. Bipolar electric charging of the internal voids was achieved through the application of high electric fields in an SF0 atmosphere. The new optimized PETP ferroelectric exhibit quite large piezoelectric coefficients up to almost 500 pCN(-1), for which unusually low elastic stiffness of only around 0.3 MPa are essential. The PETP foam ferroelectrics posses unclamped thickenss-extension resonance frequences between approximately 120 and 250 kHz, and are thus highly suitable for several established as well as novel ultrasonic-transductant applications.},
  language  = {en}
}
@article{WirgesPrzyrembelBrinkeretal.1995,
  author    = {Wirges, Werner and Przyrembel, G. and Brinker, Walter and Gerhard, Reimund and Klemberg-Sapieha, J. and Martinu, L. and Poitras, D. and Wertheimer, M. R.},
  title     = {Metallised viscoelastic control layers for light-valve projection displays},
  year      = {1995},
  language  = {en}
}
@article{WertheimerStGeorgesRobillardLerougeetal.2012,
  author    = {Wertheimer, Michael R. and St-Georges-Robillard, Amelie and Lerouge, Sophie and Mwale, Fackson and Elkin, Bentsian and Oehr, Christian and Wirges, Werner and Gerhard, Reimund},
  title     = {Amine-rich organic thin films for cell culture - possible electrostatic effects in cell-surface interactions},
  series = {Japanese journal of applied physics},
  volume    = {51},
  journal   = {Japanese journal of applied physics},
  number    = {11},
  publisher = {Japan Soc. of Applied Physics},
  address   = {Tokyo},
  issn      = {0021-4922},
  doi       = {10.1143/JJAP.51.11PJ04},
  pages     = {5},
  year      = {2012},
  abstract  = {In recent communications from these laboratories, we observed that amine-rich thin organic layers are very efficient surfaces for the adhesion of mammalian cells. We prepare such deposits by plasma polymerization at low pressure, atmospheric pressure, or by vacuum-ultraviolet photo-polymerization. More recently, we have also investigated a commercially available material, Parylene diX AM. In this article we first briefly introduce literature relating to electrostatic interactions between cells, proteins, and charged surfaces. We then present certain selected cell-response results that pertain to applications in orthopedic and cardiovascular medicine: we discuss the influence of surface properties on the observed behaviors of two particular cell lines, human U937 monocytes, and Chinese hamster ovary cells. Particular emphasis is placed on possible electrostatic attractive forces due to positively charged R-NH3+ groups and negatively charged proteins and cells, respectively. Experiments carried out with electrets, polymers with high positive or negative surface potentials are added for comparison.},
  language  = {en}
}
@article{WeinholdWegenerKuenstleretal.2000,
  author    = {Weinhold, Till and Wegener, Michael and K{\"u}nstler, Wolfgang and Seiß, Martin and G{\"o}rne, Thomas and Gerhard, Reimund},
  title     = {Porous polytetrafluoroethylene (PTFE) single-film space-charge electrets with high piezoelectric coefficients},
  issn      = {0537-9989},
  year      = {2000},
  language  = {en}
}
@article{WegenerWirgesRichteretal.2001,
  author    = {Wegener, Michael and Wirges, Werner and Richter, Kristin and K{\"u}nstler, Wolfgang and Gerhard, Reimund},
  title     = {Charge stability and piezoelectric properties of porous fluoro-polymer space-charge electrets in layer systems},
  year      = {2001},
  language  = {en}
}
@article{WegenerWirgesPaajanenetal.2007,
  author    = {Wegener, Michael and Wirges, Werner and Paajanen, Mika and Gerhard, Reimund},
  title     = {Charging behaviour and thermal stability of porous and non-porous polytetrafluoroethylene (PTFE) electrets},
  isbn      = {978-1-4244-1482-6},
  year      = {2007},
  language  = {en}
}
@article{WegenerWirgesGerhardetal.2004,
  author    = {Wegener, Michael and Wirges, Werner and Gerhard, Reimund and Dansachm{\"u}ller, M. and Schw{\"o}diauer, R. and Bauer-Gogonea, Simona and Bauer, Siegfried and Paajanen, Mika and Minkkinen, Hannu and Raukola, J.},
  title     = {Controlled inflation of voids in cellular polymer ferroelectrets : optimizing electromechanical transducer properties},
  year      = {2004},
  abstract  = {When exposed to sufficiently high electric fields, polymer-foam electret materials with closed cells exhibit ferroelectric-like behavior and may therefore be called ferroelectrets. In cellular ferroelectrets, the influence of the cell size and shape distributions on the application-relevant properties is not yet understood. Therefore, controlled inflation experiments were carried out on cellular polypropylene films, and the resulting elastical and electromechanical parameters were determined. The elastic modulus in the thickness direction shows a minimum with a corresponding maximum in the electromechanical transducer coefficient. The resonance frequency shifts as a function of the elastic modulus and the relative density of the inflated cellular films. Therefore, the transducer properties of cellular ferroelectrets can be optimized by means of controlled inflation. (C) 2004 American Institute of Physics},
  language  = {en}
}