Observation of Enhanced Unipolar Strain and Piezoelectric Charge Co-Efficient in K0.5Na0.5NbO3 Simultaneously Doped with Lithium and Antimony

Accurate determination of piezoelectric properties such as piezoelectric charge coefficients (d33) is an essential step in the design process of sensors and actuators using piezoelectric effect. In this study, a cost-effective and accurate method based on dynamic loading technique was proposed to determine the piezoelectric charge coefficient d33. Finite element analysis (FEA) model was developed in order to estimate d33 and validate the obtained values with experimental results. The experiment was conducted on a piezoelectric disc with a known d33 value. The effect of measuring boundary conditions, substrate material properties and specimen geometry on measured d33 value were conducted. The experimental results reveal that the determined d33 coefficient by this technique is accurate as it falls within the manufactures tolerance specifications of PZT-5A piezoelectric film d33. Further, obtained simulation results on fibre reinforced and particle reinforced piezoelectric composite were found to be similar to those that have been obtained using more advanced techniques. FE-results showed that the measured d33 coefficients depend on measuring boundary condition, piezoelectric film thickness, and substrate material properties. This method was proved to be suitable for determination of d33 coefficient effectively for piezoelectric samples of any arbitrary geometry without compromising on the accuracy of measured d33.

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Piezoelectric Voltage Constant and Sensitivity Enhancements Through Phase Boundary Structure Control of Lead-free (K,Na)NbO3-based ceramics

10.21203/rs.3.rs-1177124/v1 ◽

2021 ◽

Author(s):

Min-Ku Lee ◽

Byung-Hoon Kim ◽

Gyoung-Ja Lee

Keyword(s):

Material Parameter ◽

Perovskite Oxide ◽

Lead Free ◽

Boundary Structure ◽

Voltage Sensitivity ◽

Phase Boundaries ◽

Accelerometer Sensor ◽

Structure Control ◽

Piezoelectric Charge ◽

Piezoelectric Voltage

Abstract The piezoelectric voltage constant (g33) is a material parameter critical to piezoelectric voltage-type sensors for detecting vibrations or strains. Here, we report a lead-free (K,Na)NbO3 (KNN)-based piezoelectric accelerometer with voltage sensitivity enhanced by taking advantage of a high g33. To achieve a high g33, the magnitudes of piezoelectric charge constant d33 and dielectric permittivity er of KNN were best coupled by manipulating the intrinsic polymorphic phase boundaries effectively with the help of Bi-based perovskite oxide additives. For the KNN composition that derives benefit from the combination of er and d33, the value of g33 was found to be 46.9 ´ 10-3 V·m/N, which is significantly higher than those (20 - 30 ´ 10−3 V·m/N) found in well-known polycrystalline lead-based ceramics including commercial Pb(Zr,Ti)O3 (PZT). Finally, the accelerometer sensor prototype built using the modified KNN composition demonstrated higher voltage sensitivity (183 mV/g) when measuring vibrations, showing a 29% increase against the PZT-based sensor (142 mV/g).

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Effects of Vapor Phase Soldering on the Properties of Piezoceramic Materials

Additional Conferences (Device Packaging HiTEC HiTEN & CICMT) ◽

10.4071/cicmt-2012-tha24 ◽

2012 ◽

Vol 2012 (CICMT) ◽

pp. 000603-000605

Author(s):

Silke Bramlage ◽

Klaus-Jürgen Wolter

Keyword(s):

Heat Treatment ◽

Vapor Phase ◽

Lead Zirconate Titanate ◽

Piezoelectric Properties ◽

Lead Zirconate ◽

Type I ◽

Soldering Process ◽

Before And After ◽

Curie Temperatures ◽

Piezoelectric Charge

Eight different PZT (lead zirconate titanate) materials (Navy Type I and II) with Curie temperatures between 250 °C and 350 °C were subjected to a standard vapor phase soldering process with a peak temperature of 240 °C for three cycles. As indicators for the depolarization, the piezoelectric charge coefficient (d33) and the coupling coefficient (keff) were measured both before and after each heat treatment. Our studies demonstrate reductions in piezoelectric properties between 5% and 20%, depending on the Curie temperature of the corresponding material. The effects of the second and third cycle were minimal. The drop in performance, especially for materials with higher Curie temperatures, is moderate, and can be accounted for in the design of the device. Thus batch soldering processes become a viable alternative to selective soldering.

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Long-Term Stability of Ferroelectret Energy Harvesters

Materials ◽

10.3390/ma13010042 ◽

2019 ◽

Vol 13 (1) ◽

pp. 42 ◽

Cited By ~ 1

Author(s):

Muhammed Kayaharman ◽

Taylan Das ◽

Gregory Seviora ◽

Resul Saritas ◽

Eihab Abdel-Rahman ◽

...

Keyword(s):

Output Power ◽

Operating Conditions ◽

Constant Stress ◽

Center Frequency ◽

Term Stability ◽

Energy Harvesters ◽

Long Term Stability ◽

Stress Cycling ◽

Piezoelectric Charge

Cellular polypropylene (PP) has been recently used in energy harvesting applications. In this work, we investigate its viability and long-term stability under various operating conditions. Specifically, the effect of constant stress and stress cycling on output power and long-term stability of ferroelectret energy harvesters is analyzed. Our findings show that after 112 days constant stress significantly increases the piezoelectric charge constant d 33 and output power from 0.51 μW for a stress-free harvester to 2.71 μW. It also increases the harvester center frequency from 450 to 700 Hz and decreases its optimal resistance from 7 to 5.5 M Ω .

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The effect of the intrinsic electrical matrix conductivity on the piezoelectric charge constant of piezoelectric composites

Materials Research Express ◽

10.1088/2053-1591/ab5bb3 ◽

2019 ◽

Vol 7 (1) ◽

pp. 015703

Author(s):

Vincent L Stuber ◽

Tadhg R Mahon ◽

Sybrand van der Zwaag ◽

Pim Groen

Keyword(s):

Piezoelectric Composites ◽

Piezoelectric Charge

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Effect of Process Orientation on the Mechanical Behavior and Piezoelectricity of Electroactive Paper

Materials ◽

10.3390/ma13010204 ◽

2020 ◽

Vol 13 (1) ◽

pp. 204

Author(s):

Sean Yoon ◽

Jung Woong Kim ◽

Hyun Chan Kim ◽

Jaehwan Kim

Keyword(s):

Mechanical Behavior ◽

Process Orientation ◽

Linear Elastic ◽

Strong Shear ◽

Performance Deterioration ◽

Alignment Angle ◽

Anisotropic Elastic ◽

Stretching Ratio ◽

Orientation Dependency ◽

Piezoelectric Charge

This paper reports the effect of process orientation on the mechanical behavior and piezoelectricity of electroactive paper (EAPap) made from natural cotton pulp. EAPap is fabricated by a casting and wet drawing of cellulose film after dissolving cotton with LiCl and DMAc solvent. During the fabrication, permanent wrinkles, a possible factor for performance deterioration, were found in the films. Finite element method was introduced to identify the formation mechanism behind the wrinkles. The simulation results show that the wrinkles were caused by buckling and are inevitable under any conditions. The tensile and piezoelectric tests show that the orientation dependency of the stretched EAPap gives the anisotropic characteristics on both mechanical and piezoelectric properties. In this research, the anisotropic elastic moduli and Poisson’s ratios are reported. The piezoelectric charge constant of EAPap in the linear elastic is calculated. The piezoelectric charge constants of EAPap are associated with the alignment angle in the order of 45° > 0° > 90° due to the strong shear effect. The higher stretching ratio gives the higher piezoelectricity due to the alignment of the molecular chains and the microstructure in EAPap. The highest piezoelectric charge constant is found to be 12 pC/N at a stretching ratio of 1.6 and aligning angle of 45°.

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Single-pixel tactile sensor based on piezoelectric-charge-gated thin-film transistor

2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM) ◽

10.1109/aim.2016.7576867 ◽

2016 ◽

Cited By ~ 1

Author(s):

Weiwei Li ◽

Emad Iranmanesh ◽

Jeffrey A. Weldon ◽

Kai Wang

Keyword(s):

Thin Film ◽

Thin Film Transistor ◽

Tactile Sensor ◽

Single Pixel ◽

Piezoelectric Charge

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Smart Piezoelectric PZT Microcantilevers with Inherent Sensing and Actuating Abilities for AFM and LFM

MRS Proceedings ◽

10.1557/proc-459-35 ◽

1996 ◽

Vol 459 ◽

Cited By ~ 2

Author(s):

C. Lee ◽

T. Itoh ◽

J. Chu ◽

T. Ohashi ◽

R. Maeda ◽

...

Keyword(s):

Sample Surface ◽

Lateral Force ◽

Smart Structure ◽

Thin Layers ◽

Force Sensing ◽

Free Standing ◽

Atomic Force ◽

Lateral Force Microscope ◽

Dynamic Scanning ◽

Piezoelectric Charge

ABSTRACTNovel designs of the force sensing components for an atomic force microscope (AFM) and lateral force microscope (LFM) have been proposed in this study. By using PZT thin layers, a smart structure that can perform force sensing and feedback actuation at the same time is applied to the AFM. Clear images can be derived by an AFM equipped with this smart structure. A structure of two parallel PZT bars integrated on a SiO2 free standing cantilever has shown potential for operation in an LFM, because a difference in the piezoelectric charge outputs from these two beams will be induced by frictional force when the cantilever end quasi-staticly contacts with the sample surface in dynamic scanning across the surface.

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