Fabrication and Characterization of PZT Thick Films for Sensing and Actuation

Abstract

Lead Zirconate Titanate oxide (PZT) thick films with thicknesses of up to 10 µm were developed using a modified sol-gel technique. Usually, the film thickness is less than 1 µm by conventional sol-gel processing, while the electrical charge accumulation which reveals the direct effect of piezoelectricity is proportional to the film thickness and therefore restricted. Two approaches were adopted to conventional sol-gel processing -precursor concentration modulation and rapid thermal annealing. A 10 µm thick film was successfully fabricated by coating 16 times via this technique. The thickness of each coating layer was about 0.6 µm and the morphology of the film was dense with a crack-free area as large as 16 mm 2 . In addition, the structure, surface morphology and physical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) and electrical performance. The dielectric constant and hysteresis loops were measured as electric characteristics. This study investigates the actuation and sensing performance of the vibrating structures with the piezoelectric thick film. The actuation tests demonstrated that a 4 mm x 4 mm x 6.5 µm PZT film drove a 40 mm x 7 mm x 0.5 mm silicon beam as an actuator. Additionally, it generated an electrical signal of 60 mV pp as a sensor, while vibration was input by a shaker. The frequencies of the first two modes of the beam were compared with the theoretical values obtained by Euler-Bernoulli beam theory. The linearity of the actuation and sensing tests were also examined.

Synthesis and characterization of thick PZT films via sol–gel dip coating method

“…6(b) and (c)). PZT film prepared with 0.25 molar ratio of DEA has the remanent polarization of 5.7 C cm −2 and coercive voltage of 16 V. This polarization value is highly significant giving due consideration for the high thickness of the film compared to similar studies [37]. As could be seen in Fig.…”

Thick films acoustic sensors devoted to Material Testing Reactor environment measurements

“…The parameters of our sample are in the state of this art for screen printed device [13]. Moreover the coupling factor, the Curie temperature and the dielectric loss are on pair with a disc with the same PZT base [14].…”

Fabrication, characterization and test of acoustic sensors for detection of pollutants in aquatic environments

“…Considering the fact that the system is a stack of different materials with different thicknesses and mechanical properties, the resonance frequencies of the whole device are a mix of the influence of the different elements that constitute it. Indeed substrate and electrodes play a role with the frequency response of the system [8]. However with a thicker deposited PZT layer it has been shown that the structure can overcome the influence of electrodes.…”