Porous piezoelectric ceramics with 3-3-connectivity fabricated by impregnation of cellulose paper structures

Porous piezoelectric ceramics with an interconnecting pore network (3-3 piezoceramic-air-composites) are a compromising material for sensor applications. Using a biomorphous approach with pre-pyrolysed cellulose fiber paper as template for the impregnation process leads to a novel porous piezoelectric ceramic with a fiber microstructure and benefits on easy shaping of complex structures and high porosity (similar to 90 vol%). The templates were impregnated by a non-aqueous lead zirconate titanate (PZT) slurry (solid fracture of 52.3%). After residual slurry and binder removal and cellulose/carbon burn-out, sintering was carried out at 1150 degrees C. Microstructure and composition analyses were done by mu CT (Skyscan 1172, Bruker), SEM (FESEM, Helios NanoLab 600i FIB Workstation, FEI) and X-ray diffraction measurements (Kristalloflex D500, Siemens AG) evaluation. Geometric density decreased by 30% compared to dense PZT (as reference) a porosity increased from 2.4% up to 86%. The piezoelectric properties as d(33), relative permittivity and d(37) (measured by Piezo-Meter PM 300, Piezo Test) decreased up to 99%. (C) 2017 Elsevier B.V. All rights reserved.