Piezoelectric Thin Film Ultrasonic Micromotors

1991 ◽  
Vol 243 ◽  
Author(s):  
K. R. Udayakumar ◽  
J. Chen ◽  
K. G. Brooks ◽  
L. E. Cross ◽  
A. M. Flynn ◽  
...  
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Breakdown Strength ◽  
Relative Dielectric Constant ◽  
Electromechanical Coupling Factor ◽  
Lead Zirconate ◽  
Coupling Factor ◽  
New Family ◽  
Piezoelectric Thin Film

AbstractThin films of lead zirconate titanate have been fabricated for application to a new family of flexure-wave piezoelectric micromotors that are characterized by low speed and high torque. The high relative dielectric constant and breakdown strength of the films lead to high stored energy densities. Evaluation of the film as a bimorph yielded a value of -88 pC/N for the transverse piezoelectric strain coefficient, d31; the relevant electromechanical coupling factor, k31, calculated thereupon was 0.22. The development of the piezoelectric ultrasonic micromotors from the PZT thin films, and the architecture of the stator structure are described. Nonoptimized prototype micromotors show rotational velocities of 100-300 rpm at drives of 3-5 V.

Piezoelectric Behavior Based on Mixing-Doped in Lead Zirconate Titanate Ceramics and Application

2011 ◽  
Vol 189-193 ◽  
pp. 4126-4129
Author(s):  
Bing Huei Chen ◽  
Long Wu
Keyword(s):  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Electromechanical Coupling Factor ◽  
Lead Zirconate ◽  
Coupling Factor ◽  
Mechanical Quality Factor ◽  
Ceramic Technology ◽  
Zirconate Titanate ◽  
Cation And Anion Vacancies

In this investigation, we extend our previous works to improve piezoelectric properties of Pb(Zr,Ti)O3 ceramics. Modified lead zirconate titanate (PZT) piezoceramics with a composition Zr/Ti=53/47 containing a trace of mixing dopants were prepared by conventional ceramic technology sintering powder compacts. Replacement of (Zr, Ti)+4 by Nb+5, Pb+2 by Sb+3 and Mn+4 in PZT perovskite type solid solutions was accomplished by the creation of cation and anion vacancies. Modified ceramics were explored as a function of firing temperature to acquire exceedingly good piezoelectric characterizations. From the analysis results, calcined at 850°C for 2 h, and then sintered at 1280°C for 2 h, PZT piezoceramic showed the larger dielectric constant er 2013, mechanical quality factor Qm 120 and maximum electromechanical coupling factor kp 0.67. Besides, the bulk ceramic grains distribution were found to be uniform. Furthermore, the sample was found to possess piezoelectric properties, the resonance frequency being about 200 KHz suitable for acoustic sensor.

scholarly journals Electrothermal Phenomena in Ferroelectrics

Actuators ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 93
Author(s):  
Kenji Uchino
Keyword(s):  
Thermal Diffusivity ◽  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Short Circuit ◽  
Electromechanical Coupling Factor ◽  
Lead Zirconate ◽  
Coupling Factor ◽  
Open Circuit ◽  
Comprehensive Knowledge ◽  
Poling Direction

Physical properties of lead-zirconate-titanate (PZT) ceramics change according to the initial electric poling process and electrical boundary conditions. This paper reports the electrothermal, piezothermal, and piezoelectric coupling phenomena in ferroelectrics from thermodynamics viewpoints, in particular, thermal property differences between unpoled and poled PZT’s in the poling direction for open circuit and short circuit conditions. We propose a new terminology, “secondary electrothermal” coupling factor kλ, which is analogous to the electromechanical coupling factor k, relating the elastic compliances under short- and open-circuit conditions, in order to explain the fact that the short-circuit condition exhibited the larger thermal diffusivity than the open-circuit condition. On the other hand, the unpoled specimen exhibits the lowest thermal diffusivity. This tutorial paper was authored for providing comprehensive knowledge on equilibrium and time-dependent thermodynamics in ferroelectrics.

scholarly journals Effect of Polymer-Ceramic Fibre Interphase Design on Coupling Factor in Low Fibre Volume Content Piezoelectric Composites

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Tony Lusiola ◽  
Sophie Oberle ◽  
Lovro Gorjan ◽  
Frank Clemens
Keyword(s):  
Epoxy Resin ◽  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Polymer Coatings ◽  
Coupling Factor ◽  
Fibre Volume ◽  
Resin Matrix ◽  
Ceramic Fibre ◽  
Soft Polymer

In this work, we investigated different short molecule polymer coatings in piezoelectric ceramic-polymer composites with low fibre volume contents. Modifying the interphase between the piezoelectric PZT (lead zirconate titanate) fibre and the epoxy matrix thus enhances the electromechanical coupling factor for 1–3 ultrasound transducers with low fibre contents. It is known that the electromechanical coupling factor can be increased by precoating a ceramic fibre with a soft interlayer polymer [1-1-3]. In this paper, we investigate the so-called 1-1-1-3 composites composed of a ferroelectric ceramic fibre (core), a soft polymer layer (e.g., fatty acids, amides, waxes, or oils), an epoxy resin shell, and an epoxy resin matrix. Some soft polymer layers allowed the free movement of the ferroelectric fibres reducing blocking or clamping by the inactive polymeric matrix, resulting in higher electromechanical coupling factors (kt) for composites with low fibre volume contents. Using an oil-based interlayer, the dielectric constant can be significantly increased. The lowest fibre push-out stress could be achieved with the paraffin interlayer; however, no correlation with the coupling factor could be observed.

Effects of Y2O3 on the Piezoelectric Properties of PSN-PMN-PZT Composition under Various Alternating Electric Fields

2007 ◽  
Vol 544-545 ◽  
pp. 737-740
Author(s):  
Soon Chul Ur ◽  
Y.G. Choi ◽  
Joon Chul Kwon ◽  
Sung Lim Ryu ◽  
Young Geun Lee ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Electric Fields ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Strong Electric Field ◽  
Relative Dielectric Constant ◽  
Electromechanical Coupling Factor ◽  
Processing Technique ◽  
Coupling Factor ◽  
Alternating Electric Fields

0.03Pb(Sb0.5Nb0.5)O3-0.03Pb(Mn1/3Nb2/3)O3-(0.94-x)PbTiO3-xPbZrO3 ceramics doped with Y2O3 were synthesized by conventional bulk ceramic processing technique. Phases analysis, microstructures and piezoelectric properties were investigated as a function of Y2O3 contents (0.03, 0.05, 0.1 0.3, 0.5 and 0.7 wt.%). Microstructures and phases information were characterized using a scanning electron microscope (SEM) and an X-ray diffractometer (XRD). Relative dielectric constant (K33 T) and coupling factor (kp) were obtained from the resonance measurement method. Both K33 T and kp were shown to reach to the maximum at 0.1wt.% Y2O3. In order to evaluate the stability of resonance frequency and effective electromechanical coupling factor (Keff) as a function of Y2O3 contents under strong electric field, the variation of resonance and anti-resonance frequency were also measured using a high voltage frequency response analyzer(FRA5096) under various alternating electric fields from 10V/mm to 80V/mm. It was shown that the effective electromechanical coupling factor was stabilized along with increasing Y2O3 contents.

High Electromechanical Coupling Piezoelectrics - How High Energy Conversion Rate is Possible

1996 ◽  
Vol 459 ◽  
Author(s):  
Kenji Uchino
Keyword(s):  
Energy Conversion ◽  
Lead Zirconate Titanate ◽  
Conversion Rate ◽  
Electromechanical Coupling ◽  
Crystal Form ◽  
Lead Zirconate ◽  
High Energy ◽  
Coupling Factor ◽  
Lead Zinc ◽  
Titanate Ceramics

ABSTRACTA new category of piezoelectric ceramics with very high electromechanical coupling was discovered in a lead zinc niobate:lead titanate solid solution in a single crystal form. The maximum coupling factor k33 reaches 95%, which corresponds to the energy conversion rate twice as high as the conventional lead zirconate titanate ceramics. This paper reviews the previous studies on superior piezoelectricity in relaxor ferroelectric: lead titanate solid solutions and on the possible mechanisms of this high electromechanical coupling.

Effects of CeO2 on the Piezoelectric Properties of PSN-PMN-PZT Composition under Various Alternating Electric Fields

2007 ◽  
Vol 124-126 ◽  
pp. 203-206
Author(s):  
Man Soon Yoon ◽  
Seung Hwan Yi ◽  
Y.G. Choi ◽  
Joon Chul Kwon ◽  
K.S. Lee ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Electric Fields ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Strong Electric Field ◽  
Relative Dielectric Constant ◽  
Electromechanical Coupling Factor ◽  
Processing Technique ◽  
Coupling Factor ◽  
Alternating Electric Fields

0.03Pb(Sb0.5Nb0.5)O3-0.03Pb(Mn1/3Nb2/3)O3-(0.94-x)PbTiO3-xPbZrO3 ceramics doped with CeO2 were synthesized by conventional bulk ceramic processing technique. Phases analysis, microstructures and piezoelectric properties were investigated as a function of CeO2 contents (0.03, 0.05, 0.1 0.3, 0.5 and 0.7wt%). Microstructures and phases information were characterized using a scanning electron microscope (SEM) and an X-ray diffractometer (XRD). Relative dielectric constant (K33 T) and coupling factor (kp) were obtained from the resonance measurement method. Both K33 T and kp were shown to reach to the maximum at 0.1wt% CeO2. In order to evaluate the stability of resonance frequency and effective electromechanical coupling factor (Keff) as a function of CeO2 addition under strong electric field, the variation of resonance and anti-resonance frequency were also measured using a high voltage frequency response analyzer(FRA5096) under various alternating electric fields from 10V/mm to 80V/mm. It was shown that effective electromechanical coupling factor was increased by increasing the CeO2 additions.

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