Preparation and characterization of piezoelectric ceramic-polymer composite thick films by aerosol deposition for sensor application

Lead zirconate titanate (PZT)-based piezoelectric ceramic and polyvinylidene fluoride (PVDF) organic composite thick films (similar to 20 mu m in thickness) were deposited on a 4-in, diameter Pt/Ti/SiO2/Si substrate and a 2-in. diameter Ag-Pd/sapphire substrate by aerosol deposition Using a single 4-in. size nozzle for use as a tactile-sensor device. The PVDF content was varied from 3 to 10 vol% and the films deposited on silicon and sapphire were annealed at 700 and 900 degrees C, respectively. The annealed films showed a relatively high density, even at a 10 vol% of PVDF-piezoelectric ceramic composition. as well as good adhesion to the substrate after annealing. The relative dielectric constant of the composite film decreased sharply with increasing PVDF content, while the piezoelectric d(33) coefficient was conserved at a relatively high value. Therefore, the g(33) coefficient increased and showed the highest value at 3 vol% PVDF The g(33) values of the as-deposited, 700 degrees C annealed and 900 degrees C annealed piezoelectric ceramic-PVDF composite films were 7.77, 16.3 and 41.5 (10(-3) m(2)/N), respectively. (C) 2009 Elsevier B.V. All rights reserved.