TY - JOUR A1 - Künstler, Wolfgang A1 - Xia, Zhongfu A1 - Weinhold, Till A1 - Pucher, Andreas A1 - Gerhard, Reimund T1 - Piezoelectricity of porous polytetrafluoroethylene single- and multiple-film electrets containing high charge densities of both polarities Y1 - 2000 ER - TY - JOUR A1 - Gerhard, Reimund A1 - Künstler, Wolfgang A1 - Görne, Thomas A1 - Pucher, Andreas A1 - Weinhold, Till A1 - Seiß, Martin A1 - Xia, Zhongfu A1 - Wedel, Armin A1 - Danz, Rudi T1 - Porous polytetrafluoroethylene space-charge electrets for piezoelectrical applications Y1 - 2000 ER -