Piezoelectric Thick Films: Preparation and Characterization

PZT/PZT and PZT/BiT Composite Piezo-Sensors in Aerospace SHM Applications: Photochemical Metal Organic+Infiltration Deposition and Characterization

“…The thick films mostly have higher Ra due to encompassing larger particles compared to thin films. The smaller the Ra, the narrower and sharper peaks in the X-ray diffraction patterns could be observed, addressed in [1]. The sol-gel infiltration shows a great contribution to the improvement of the surface roughness, electrode connection and the precision of the profilometry.…”

“…Piezoelectric thin films have been used vastly as sensors, accelerometers, micro-motors, and many other low-force electromechanical (E/M) applications [1]. However, high-frequency transducers for structural health monitoring and vibration control systems usually require higher thickness to convey appropriately E/M stimulation loads.…”

“…During the second step, preparation of a homogenous suspended mixture is so important to reduce the possibility of the agglomeration [19,23]. Attention should be given to the inappropriate mixing of the powder within the piezoelectric solution and long staying of the mixture before deposition, which could possibly yield to 1) forming the surface layers, 2) strengthening the surface tension forces, 3) sedimentation of the suspended powder, and therefore, 4) agglomeration after the coating process. To avoid the agglomeration before and during the preparation process of thick films, researchers usually apply high molecular-weight solvents, such as acetic acid (60.05 g/mol), hexane (86.17 g/mol), methoxyethanol (76.09 g/mol), and α-terpined (154.25 g/mol) [1], binders including polyvinylpyrrolidone, plasticizers such as polyethylene glycol and organic diffusers such as buthoxyethoxy-ethyl acetate.…”

“…microns help avoid the additional adhesives, plasticizers, and solvents. Hence, besides reducing the impurities, the length of time spent on drying and pyrolyzing of thick piezo-ceramic films -that sometimes exceeds 24 hours-is considerably diminished[1]. Refraining from solvents with high molecular masses leads to a reduction of the formation of large porosities during the evaporation of volatile substances.Thermal treatment and post-processing of thick films after coating in the hybrid sol-gel method do not differ much from the method implemented for thin films, mentioned in[32].…”

Electrohydrodynamic jet printing of PZT thick film micro-scale structures

“…The most commonly used piezoelectric material is lead zirconate titanate (PZT) because of its high piezoelectric constant, relative permittivity and electromechanical coupling coefficient [4]. Recently, PZT thick film has attracted considerable attention because sensing signals, strains and actuating forces are closely related to the film thickness [5][6][7]. Consequently, piezoelectric thick films (>5 µm) are favourable for the MEMS devices requiring large strains, large actuating forces and high frequency such as micro-power harvesters [8], micro-actuators [9] and high resolution piezoelectric ultrasonic transducers [10].…”