Influence of aspect ratio on effective electromechanical coupling of nanocomposites with lead zirconate titanate nanowire inclusion

2011 ◽  
Vol 22 (16) ◽  
pp. 1879-1886 ◽  
Author(s):  
Clark Andrews ◽  
Yirong Lin ◽  
Haixiong Tang ◽  
Henry A. Sodano
Keyword(s):  
Aspect Ratio ◽  
Mechanical Loading ◽  
Polymer Matrix ◽  
Lead Zirconate Titanate ◽  
Coupling Coefficient ◽  
High Aspect Ratio ◽  
Electromechanical Coupling ◽  
Lead Zirconate ◽  
Electromechanical Coupling Coefficient ◽  
Curved Surfaces

Piezoelectric ceramics offer exceptional sensing and actuation properties, however, they are prone to breakage and are difficult to apply to curved surfaces in their monolithic form. One method to alleviate these issues is through the use of 0–3 active composites, which are formed by embedding piezoelectric particles into a polymer matrix that protects the ceramic from breaking under mechanical loading. This class of material offers certain advantages over monolithic materials; however, they have seen little use due to the low electromechanical coupling offered by these materials. Here, we demonstrate that by controlling the aspect ratio of the filler, the electromechanical coupling coefficient can be significantly improved. For all volume fractions tested, nanocomposites with high aspect ratio lead nanowires filler had higher coupling with increases as large as 2.3 times. Furthermore, the nanocomposite’s coupling was more than 50% of the piezoceramic fillers’ when nanowires were used.

scholarly journals Piezoelectric Properties of PVDF Modified 3-3 Type Cement-Based Piezoelectric Composites

2020 ◽  
Author(s):  
Wei Liu ◽  
lehui zhang ◽  
Yu Cao ◽  
Jianhong Wang ◽  
Peikang Bai ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Coupling Coefficient ◽  
Polyvinylidene Fluoride ◽  
Electromechanical Coupling ◽  
Lead Zirconate ◽  
Electromechanical Coupling Coefficient ◽  
Piezoelectric Composites ◽  
Voltage Coefficient ◽  
Changing Trend ◽  
Piezoelectric Strain

Abstract In this study, 3-3 type cement-based piezoelectric composites were prepared by casting Portland cement paste in porous lead zirconate titanate (PZT) ceramics, then the Polyvinylidene fluoride (PVDF) of N-Methylpyrrolidone (NMP) solvent with concentration of 50-200 mg/ml was utilized to modify the PZT-PC composites. The influence of PVDF concentration on the density, microstructure, dielectric, piezoelectric and electromechanical properties were investigated. The results indicate that the density of PZT-PC composites increased gradually with PVDF concentration for the increasing combined weight of PVDF with the composites. The introduction of PVDF has also contributed to the reduction of leakage current during the poling and testing process, which led to increased relative permittivity εr and longitudinal piezoelectric strain coefficient d33, while the dielectric loss tanδ and longitudinal piezoelectric voltage coefficient g33 demonstrated an opposite changing trend. Both the thickness electromechanical coupling coefficient Kt and planar electromechanical coupling coefficient Kp of the PZT-PC composites increased with PVDF concentration. The acoustic impedance (Z) of PVDF modified PZT-PC composites ranged from 6.89 to 7.65 MRayls, making it suitable for applications in the health monitoring of civil engineering.

Fluid Manipulation by Bio-Mimetic Cilia

2007 ◽  
Author(s):  
Kieseok Oh ◽  
Jae-Hyun Chung ◽  
Santosh Devasia ◽  
James J. Riley
Keyword(s):  
Aspect Ratio ◽  
Lead Zirconate Titanate ◽  
High Aspect Ratio ◽  
Small Volume ◽  
Lead Zirconate ◽  
Maximum Displacement ◽  
Assembly Method ◽  
Fluidic Device ◽  
Structure Assembly ◽  
Fluid Manipulation

This paper describes the fabrication and actuation of bio-mimetic cilia for fluid manipulation. High aspect ratio cilia made of polydimethylsiloxane (PDMS) were successfully assembled in a microfluidic device by our novel fabrication method. This method was to release the PDMS cilia from a Si mold and assemble the cilia in a device. All the process was performed under water in order to avoid the stiction and pairing of the PDMS cilia. The underwater assembly method enabled a high aspect ratio PDMS structure assembly in a fluidic device. The PDMS cilia were actuated in air and water by lead-zirconate-titanate (PZT) microstage. In the fabricated device, the maximum displacement of the cilia was observed at 120Hz in air and at 50Hz in de-ionized (DI) water with our experimental condition. The actuated cilia in a solution produced convective and propulsive fluid flow near the cilia structure. The developed device can be used for precise handling of small volume sample (e.g., 1 μL).

Variation of Material Properties of Piezoelectric Ceramics due to Electric Loading Evaluated by Resonance Frequency

2007 ◽  
Vol 345-346 ◽  
pp. 1521-1524 ◽  
Author(s):  
Mamoru Mizuno ◽  
Nozomi Odagiri ◽  
Mitsuhiro Okayasu
Keyword(s):  
Electric Field ◽  
Resonance Frequency ◽  
Lead Zirconate Titanate ◽  
Material Properties ◽  
Electromechanical Coupling ◽  
Domain Switching ◽  
Piezoelectric Ceramics ◽  
Lead Zirconate ◽  
Electromechanical Coupling Coefficient ◽  
Resonance Frequencies

In the present paper, lead zirconate titanate (PZT) and lead titanate (PT) piezoelectric ceramics were subjected to both high electric field (which is higher than the coercive electric field) with low frequency and low electric field with high frequency (which is the resonance frequency). After applying certain electric field systematically, resonance and anti-resonance frequencies and an electrostatic capacity were measured by means of an impedance analyzer, and an electromechanical coupling coefficient, a dielectric constant, an elastic coefficient and a piezoelectric constant were evaluated from the frequencies and capacity measured. Then variation of the material properties in process of time was investigated experimentally, and the dependence of the variation of the properties due to mainly domain switching on conditions of applied electric field was elucidated.

scholarly journals High aspect ratio lead zirconate titanate tube structures: II. Directed assembly via dielectrophoresis

2012 ◽  
Vol 6 (1) ◽  
pp. 43-51
Author(s):  
Vladimír Kovaľ
Keyword(s):  
Aspect Ratio ◽  
Electric Field ◽  
Lead Zirconate Titanate ◽  
High Aspect Ratio ◽  
Colloidal Suspension ◽  
Lead Zirconate ◽  
Uniform Electric Field ◽  
Outer Diameter ◽  
Electrode Gap ◽  
Zirconate Titanate

This paper reports on the controlled manipulation of high aspect ratio ferroelectric microtubes on pre-patterned templates by dielectrophoresis. Microtubes of ferroelectric lead zirconate titanate (PZT, a chemical formula of Pb(Zr0.52Ti0.48 )O3) with an outer diameter of 2 ?m, a length of about 30 ?m and a wall thickness of 400 nm were prepared by vacuum infiltration method using macroporous silicon templates. To position and align tubes at designed places, an alternating electric field was applied to a colloidal suspension of PZT tubes through lithographically defined microelectrodes. This would enable creation of a stable electrical connection to individual tubes for making a testing structure for rapid electrical characterization. Electric-field assisted assembly experiments demonstrated that the frequency and magnitude of the applied electric field control dielectrophoretic long-range forces, and hence spatial movement of the tubes in a non-uniform electric field. The most efficient biasing for the assembly of tubes across the electrode gap of 12 ?m was a square wave signal of 5 Vrms and 10 Hz. By varying the applied frequency in between 1 and 10 Hz, an enhancement in tube alignment was observed due to possible changes in dielectrophoretic torque. The results indicate a great potential for utilizing dielectrophoresis in construction of more complex, hierarchical 3-D device structures using the PZT 1-D like tubes as the building units.

scholarly journals Acoustic instrumentation of the new generation of MTR: effect of nuclear radiation on modified Bismuth Titanate piezoelectric elements

2020 ◽  
Vol 225 ◽  
pp. 04012
Author(s):  
JY. Ferrandis ◽  
O. Gatsa ◽  
P. Combette ◽  
D. Fourmentel ◽  
C. Destouches ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Bismuth Titanate ◽  
Piezoelectric Materials ◽  
Lead Zirconate ◽  
Nuclear Radiation ◽  
Electromechanical Coupling Coefficient ◽  
Jozef Stefan Institute ◽  
Stefan Institute ◽  
New Generation

In this article we present a first part of the results obtained during an irradiation campaign conducted at the Jozef Stefan Institute to observe the behaviour of piezoelectric materials under gamma and neutron flux. Specific instrumentation has been developed and has enabled the monitoring throughout the irradiation of several materials such as lead zirconate titanate (PZT) or modified Bismuth Titanate (BiT) in either massive or thick film form. Various parameters such as resonance frequency, electromechanical coupling coefficient, electrical capacitance, dielectric losses were measured as a function of the flow and dose received. The results obtained confirm that the samples work up to doses of 10 18 n°/cm2 and that the behaviour of the samples varies according to their composition and form.

ELECTROMECHANICAL COEFFICIENTS OF MAGNETOELECTRIC PZT–CoFe2O4 COMPOSITE

2000 ◽  
Vol 14 (17n18) ◽  
pp. 663-674 ◽  
Author(s):  
K. SRINIVAS ◽  
G. PRASAD ◽  
T. BHIMASANKARAM ◽  
S. V. SURYANARAYANA
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
External Magnetic Field ◽  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Electromagnetic Coupling ◽  
Lead Zirconate ◽  
Electromechanical Coupling Coefficient ◽  
Sum Rule ◽  
Magnetoelectric Composite

The magnetoelectric property of composite materials consisting of piezoelectric and piezomagnetic constituents are of interest since the stresses induced in them on application of an external magnetic field are converted into electrical signals. The electrical output is primarily due to electromagnetic coupling between the two participating phases. The present paper deals with the evaluation of the electromechanical coupling in the magnetoelectric composite consisting of 50% lead zirconate titanate (Pb0.96Sr0.04Ti0.47Zr0.53O3) and 50% CoFe2O4, the composition having maximum magnetoelectric conversion efficiency. A sum rule is proposed to calculate the electromechanical coupling coefficient and the results are correlated with the experimental data.

Micro-Robotic Actuation Units Based on Thin-Film Piezoelectric and High-Aspect Ratio Polymer Structures

2014 ◽  
Author(s):  
Minchul Shin ◽  
Jongsoo Choi ◽  
Ryan Q. Rudy ◽  
Christopher Kao ◽  
Jeffrey S. Pulskamp ◽  
...  
Keyword(s):  
Thin Film ◽  
Aspect Ratio ◽  
Lead Zirconate Titanate ◽  
High Aspect Ratio ◽  
Low Voltage ◽  
Weight Bearing ◽  
Lead Zirconate ◽  
Dynamic Responses ◽  
Low Voltage Operation ◽  
Fabrication Procedure

A fabrication procedure is presented for creating microactuation elements that link piezoelectric thin-films with high-aspect ratio parylene microstructures. Resulting actuators permit relatively large rotational motions for low voltage operation, while maintaining large weight-bearing capacity. Actuator fabrication is performed on a silicon wafer though a combination of metal and thin-film lead-zirconate-titanate (PZT) deposition and patterning, parylene refill of high-aspect ratio trenches, and dry release of moving parts from the silicon substrate. Static and dynamic responses of various test structures are measured, to estimate material properties of the integrated PZT-polymer structures, for use in future actuator modeling and optimization.

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