Lead Zirconate Titanate Materials Research Articles

Imaging localisation of damages on switch rail foot based on laser ultrasonic testing

ABSTRACT The corrosion on the switch rail’s foot may easily lead to rail breakage. Laser ultrasound detection is often used to assess the integrity of rails. Nevertheless, the inadequate photoacoustic conversion efficiency and vulnerability to surface interference of the entirely non-contact laser ultrasound result in a diminished signal-to-noise ratio (SNR), hence impeding the efficient detection and analysis of minor damages in the rail. This work demonstrates piezoceramic material lead zirconate titanate (PZT) wafers in conjunction with a pulsed laser to create a sensor array capable of accurate array image inspections. The PZT sensor arrays are manufactured in a flexible format that may be easily installed and altered to complicated geometries. Pulsed lasers are used to achieve dense and high-frequency array excitation. This study proposes a novel probabilistic picture location identification strategy by merging the variable mode decomposition algorithm based on parameter optimization (PVMD) and the principle component analysis (PCA) algorithm. The aim is to enhance the SNR and increase the accuracy of damage findings. Simulation and experimental tests have demonstrated the accuracy of the suggested mechanisms and algorithms in identifying damaged regions.

Damping analysis of a transversely isotropic piezothermoelastic nanobeam resonator based on the MGT thermoelasticity

The present work investigates the vibration of a piezothermoelastic nanobeam in the frame of Moore–Gibson–Thompson (MGT) thermoelasticity theory. Closed form analytical expressions for the thermoelastic damping in terms of quality factor and frequency shift for a homogeneous transversely isotropic piezothermoelastic (PTE) beam is derived by using Euler–Bernoulli beam theory and complex frequency approach. Detailed analysis of damping of vibration owing to thermal fluctuations and electric potential in the present context under three sets of boundary conditions is attempted to investigate the influence of modes of vibration, electric potential, and beam length on energy dissipation caused by thermoelastic damping in PTE beam resonators. Analytical results are illustrated with the help of graphical plots on numerical findings in the case of the nanobeam resonator of Lead Zirconate Titanate (PZT-5A) material. The investigation brings out some significant key findings and observations in view of MGT heat conduction model.

Modelling and Characterization Piezoelectric Transducer for Sound Wave Energy Harvesting

Energy harvesting system is using ambient energy conversion in the environment. The environmental energy will be converted into usable electrical energy that can be used in controlling wireless electronic devices. The available mechanical vibration from the sound energy will then be converted to electrical energy by using a piezoelectric transducer. The size of the piezoelectric represents the surface area of the electrode on the piezoelectric model. A smaller size piezoelectric transducer is unable to produce a good vibration due to the smaller surface area. The bigger dimension of the piezoelectric model would be able to harvest more electrical energy output because the vibration from the bigger piezoelectric model which would able to produce more sound wave energy. The piezoelectric material Lead Zirconate Titanate (PZT-5H) vibration is focused on the resonance frequency at below 1 kHz with sound level decibel is between the range of 35-100 dB. This research is to concentrate on rectangular and trapezium-shaped cantilever. The trapezium shaped cantilever produces higher energy output due to its shape which has better in terms of stress and strain distribution. In addition, researchers have modelled and validated energy harvesters with different proof masses shapes. The improved piezoelectric vibrational energy harvester has a trapezoidal beam and an added triangular proof mass. The arrangement of the piezoelectric tested in parallel, series, combination series and parallel configuration to investigate the performance of the output power generated from the sound wave. The rectangular and trapezium shaped cantilever are resulted in a resonant frequency of 269.4 Hz and 269.88 Hz, respectively. The rectangular and trapezium shaped cantilever produced a maximum output voltage of 3.105 V and 3.635 V respectively. The piezoelectric output during the parallel array configuration, which is 5.636 V, 0.497 mA and 2.803 mW. The output power produced by parallel is 81 % higher than compare in series array configuration and 35.8 % higher than combination of series and parallel. Thus, the produced energy output 5 V would be able to apply at several low power supply applications such as mobile phones, power bank or wireless sensor networks (WSN).

Piezoelectric ceramic materials on transducer technology for energy harvesting: A review

Recently, energy harvesting through the means of piezoelectric transducer technology has increasingly attracted the attention of engineers and scientists in producing/generating electricity for human consumption. However, understanding of piezoelectric materials for application in piezoelectric transducer devices in energy harvesting remains important in today’s energy systems engineering. Thus, the present review study is centered on piezoelectric materials for a better understanding of the properties of different piezoelectric materials (ceramic) when placed under mechanical stress or vibration and electrical field during energy harvesting using transducer devices. With the available literature, lead zirconate titanate materials showed to be the most common piezoelectric material with a high energy-generating performance but possessed more mechanical failure and also compromised in a harsh environment compared to lead-free piezoelectric materials. As such, the authors conclude that lead-free piezoelectric materials, such as zinc oxide and barium titanate, remain the best conducive piezoelectric material over lead zirconate titanate, which basically affects the human environment due to its toxicity. Thus, to widen the use of lead-free piezoelectric materials in energy harvesting, owing to their improved properties and environment-friendly nature, the authors recommend further enhancement of the lead-free piezoelectric material properties via nanodielectric filler incorporations using the spark plasma sintering technique.

Annealing-Dependent Morphotropic Phase Boundary in the BiMg0.5Ti0.5O3-BiZn0.5Ti0.5O3 Perovskite System.

The annealing behavior of (1-x)BiMg0.5Ti0.5O3–xBiZn0.5Ti0.5O3 [(1-x)BMT–xBZT] perovskite solid solutions synthesized under high pressure was studied in situ via X-ray diffraction and piezoresponse force microscopy. The as prepared ceramics show a morphotropic phase boundary (MPB) between the non-polar orthorhombic and ferroelectric tetragonal states at 75 mol. % BZT. It is shown that annealing above 573 K results in irreversible changes in the phase diagram. Namely, for compositions with 0.2 < x < 0.6, the initial orthorhombic phase transforms into a ferroelectric rhombohedral phase. The new MPB between the rhombohedral and tetragonal phases lies at a lower BZT content of 60 mol. %. The phase diagram of the BMT–BZT annealed ceramics is formally analogous to that of the commercial piezoelectric material lead zirconate titanate. This makes the BMT–BZT system promising for the development of environmentally friendly piezoelectric ceramics.

Improving the performance of ultrasound transducer using simulation and modeling

Improving medical imaging using ultrasound is important in order to get a high- resolution medical image, this research aims to achieve a physical modeling and simulation of an ultrasound transducer (UT) showing the electrical impedance of the piezoelectric material, in order to increase the transducer performance at both high and low frequencies by choosing a suitable piezoelectric material with good impedance. we adopted in this research Lead Zirconate Titanate material (PZT4), and performed modeling using mathematical equations that describe the actual physical behavior in the transducer structure and made a graphic user interface (GUI) using Matlab environment that demonstrate it, and display the electrical impedance of the piezoelectric material. As well as using Simulation by Finite Elements Methods (FEM) using On Scale environment and comparing the results in both of them. The results matched at a certain frequency, to give a clear image in the deep areas of the body. This later enables us to make modifications to the transducer structure and add backing layer and matching layer for the piezoelectric material.

Ceramic-Based Piezoelectric Material for Energy Harvesting Using Hybrid Excitation.

This paper analyzes the energy efficiency of a Micro Fiber Composite (MFC) piezoelectric system. It is based on a smart Lead Zirconate Titanate material that consists of a monolithic PZT (piezoelectric ceramic) wafer, which is a ceramic-based piezoelectric material. An experimental test rig consisting of a wind tunnel and a developed measurement system was used to conduct the experiment. The developed test rig allowed changing the air velocity around the tested bluff body and the frequency of forced vibrations as well as recording the output voltage signal and linear acceleration of the tested object. The mechanical vibrations and the air flow were used to find the optimal performance of the piezoelectric energy harvesting system. The performance of the proposed piezoelectric wind energy harvester was tested for the same design, but of different masses. The geometry of the hybrid bluff body is a combination of cuboid and cylindrical shapes. The results of testing five bluff bodies for a range of wind tunnel air flow velocities from 4 to 15 m/s with additional vibration excitation frequencies from 0 to 10 Hz are presented. The conducted tests revealed the areas of the highest voltage output under specific excitation conditions that enable supplying low-power sensors with harvested energy.

Characterization of the piezoelectric lead zirconate titanate catalyzed degradation of rhodamine B and methylene blue dyes by smartphone-based colorimetry

A typical catalytic process has been demonstrated for the well-known piezoelectric material lead zirconate titanate (PbZT). An easy and economical smartphone-based system is used to quantify the piezocatalytic degradation of the rhodamine B (RhB) and methylene blue (MB) dyes. Colorimetry is used for determining the unknown concentrations of the dyes during the piezocatalytic degradation. The values using smartphone-based colorimetry were compared with those obtained with a conventional spectrophotometer. The values obtained with the smartphone and the spectrophotometer were in good agreement. Almost 86% of RhB and 73% of MB were degraded by the PbZT piezocatalyst in 90 min during sonication.

Corrosion assessment of structural components using electro mechanical impedance

Rapid innovation in interdisciplinary technology emphasized the data acquisition system to evaluate the structural integrity by combining with advance sensing techniques. These smart sensors with impedance methodology has shown an excellent potential in assessing the structural health condition and provided an alternative to many sophisticated Non destructive monitoring systems. The sensitivity of electro mechanical impedance technique in detecting local incipient damages is enhanced with piezoelectric mechanism of lead zirconate titanate materials and with conductance signatures these materials can determine the dynamic variations in structural properties more effectively. In the present work numerical finite element analysis is conducted on simply supported RCC beam in Abaqus software with reinforcement subjected to corrosion in five stages with different reduction rates and coupled with piezoelectric transducers along the length to implement the impedance strategy. These surface bonded piezoelectric patches are electrically excited with an external voltage under specific frequency range to conduct linear perturbation harmonic analysis and the output conductance responses of healthy and corroded beams from different sensor locations are captured and compared. The peak shifting nature of signature pattern will serve as an indicator to diagnose the corrosion severity and propagation in structural components. The simulation results of proposed impedance technique showed the feasibility of employing piezoelectric materials to identify corrosion activity in structural members with electromechanical conductivity signatures.

Enhanced Bipolar Strain and Electrocaloric Response in Gadolinium/Tantalum Co-Substituted Sodium Bismuth Titanate Lead-Free Ceramics

High performance piezoelectric materials with an ABO3 perovskite structure have received growing attention in recent research due to their technological applications in sophisticated research, medical and defence devices like piezoelectric sensors, transducers, ultrasonic motors, nano-positioners, actuators and imaging devices, etc. The technical utility of these materials stems from the various possibilities they offer for cation substitution in the A (or) B sites, which provide valuable opportunities for the optimization and tailoring of desired properties. To date, lead based perovskites, such as lead zirconate titanate (PZT), PZN-PT, and PMN-PT materials, have been extensively investigated in the literature. Although lead based materials exhibit highest piezoelectric coefficients, their wide-scale application has often been hampered by considering the toxicity of lead and its effect on environment and health. This triggered the search for alternative materials that could replace the lead-based ceramics and results in less-hazardous production methods, use and recycling. This has led to a continuous search of potentially attractive alternative lead-free ceramic materials to their counterpart lead based materials for specific applications. Among various kinds of lead-free piezoelectric materials, Na0.5Bi0.5TiO3 (NBT)-based materials are considered to be promising candidates for replacing the lead-based materials. They have been extensively investigated by the condensed materials physics community because of their complicate phase transitions and superior piezo-response. Compared to various chemical substitutions, tantalum (Ta) substitution provides superior electro-strain for the NBT- based ferroelectrics, while the effect of tantalum oxide additive was rarely reported. Gd3+ and Ta5+ co-substituted (Na0.5Bi0.497Gd0.003)Ti1-xTaxO3 (NBGT-Tax) lead-free piezoelectric ceramics are synthesized by using hydrothermal technique. The influence of Ta5+ substitution on the sintering, microstructure, phase transition, and various electrical properties of NBGT ceramics was investigated. Tantalum substitution has no remarkable effect on the microstructure and densification within the studied doping composition. The X-ray diffraction studies revealed that both NBGT-Tax (x=0.000) and NBGT-Tax (x=0.003) ceramics exhibited single phases monoclinic crystal structure with Cc phase. However, with substitution of tantalum the antiferroelectric phase zone gets broader. Simultaneously, the temperature for a ferroelectric to antiferroelectric phase transition is reduced along with an increase in temperature for a transition from antiferroelectric phases to paraelectric phases. This results indicate that tantalum occupies B site of the perovskite structure behaving as a donor, producing A-site cation vacancies. The undoped NBGT ceramics shows good ferroelectric and piezoelectric properties (remnant polarization Pr = 34.2 μC/cm2). The value of remnant polarization was found to increase with Ta substitution along with an increase in coercive field as shown in the figure attached. This is because of the ferroelectric properties being influenced by composition and its homogeneity, defects, external field and orientation of domains, which eventually contributed to the materials response. Meanwhile, the addition of Ta leads to an increase in the electro-strain, together with a higher normalized strain. Moreover, the materials with temperature dependent polarization can be used for solid state cooling applications. The NBGT-Tax compositions shows decrement in the remnant polarization with the increasing temperature which causes increment in the change in entropy. Consequently, the material exhibits the conventional electrocaloric effect (ECE). This simultaneous presence of large field-induced bipolar strain and ECE response along with isothermal change in entropy opens window for great potential applications in the field of electronic devices. Figure 1

Investigation of the dynamic properties of on-chip coupled piezo/photodiodes by time-resolved atomic force and Kelvin probe microscopy

We have studied the dynamic properties of hybrid devices in which the piezoelectric material lead zirconate titanate is integrated with silicon photodiodes on-chip. Such an integrated system enables direct conversion of light energy into mechanical deformation and motion, opening up new pathways for light propulsion in microrobots and nanorobots. By operating our devices under alternating illumination and simultaneously recording the time-dependent deformation and surface potential, we were able to derive frequency and voltage dependent time constants and phase relations between photovoltage and deformation. We observed that the silicon top contact resistance limits the response time to 6 ms in small area devices in which the capacitance is low. Furthermore, we observed a phase transition at low frequency that seems to be consistent with the occurrence of a negative capacitance. Our method of using time-dependent atomic force and Kelvin probe force microscopy proves to be suitable for the investigation of nanoscale, dynamic properties of light-driven piezo systems and can lead the design of next generation devices.

Multifunctional flexible sensor array-based damage monitoring for switch rail using passive and active sensing

A passive monitoring technique for switch rails will be very attractive because it does not require extra excitations and can realize large area monitoring. However, complex wheel-rail interactions and sparse sensors will affect the accuracy of local damage identification. In contrast, an active monitoring technique has high local damage quantification ability but has low efficiency for large area monitoring. This study firstly presents a combination of piezoceramic material Lead zirconate titanate (PZT) wafers with accelerometers to configure a multifunctional sensor array that brings together active and passive monitoring mechanisms. The multifunctional sensor arrays are produced in a flexible form, which are adapted to complex geometry and are easy to install. In complementary passive monitoring, each sub area’s health state between 2 accelerometers is represented by reconstructing transfer functions, which are calculated from rail vibrations. The reconstructed transfer function in conjunction with principal component analysis (PCA)-based feature extraction is utilized for estimating the damaged sub area. Then accurate local damage identification can be realized through the active guided waves technique and correlation-based diagnostic imaging in conjunction with singular value decomposition (SVD). Simulation and experimental studies show the proposed mechanisms can identify the damaged sub area and basically extract damage locations with different lengths correctly with the sparse sensor array. Finally, based on a controlled experiment, the causes of the errors are evaluated and analyzed. The proposed mechanism can simplify data analysis, save monitoring time, and decrease the final cost.

An Ultrasonic Rheometer to Measure Gas Absorption in Ionic Liquids: Design, Calibration and Testing.

The first goal of this study is to identify the ideal piezoelectric material for the manufacturing of rheological reflectance ultrasonic sensors. The second goal is to integrate the ultrasonic rheometer within a gas absorption reactor and to measure viscosity changes in an ionic liquid (IL) caused by gas absorption. To achieve the objectives, bismuth titanate, lead titanate, lead metaniobate and lead zirconate titanate materials in layer, tungsten bronze and perovskite structures were assembled on aluminum delay lines and tested under thermal cycling between room temperature and 150 °C. The results showed that lead metaniobate in tungsten bronze structure is the most suitable material for long time duration thermal cycling. Therefore, the ultrasonic rheometer was assembled using this material and installed in a pressurized reactor to test a reference IL at the operating conditions of 50 °C and at a pressure of 80 bar. The reference IL was saturated with nitrogen as well as hydrogen gas. Viscosity signals remained constant under the hydrogen atmosphere, while in nitrogen atmosphere the absorption of the gas lead to a rise in the value of viscosity.

Piezoelectric sensor–based damage progression in concrete through serial/parallel multi-sensing technique

Structural damage detection using unmanned Structural Health Monitoring techniques is becoming the need of the day with the technologies available presently. Sensors made of Lead Zirconate Titanate materials, due to their simplicity and robustness, are increasingly used as an effective monitoring sensor in Structural Health Monitoring. Continuous monitoring of the structures using Lead Zirconate Titanate sensors often results in a laborious data retrieval process due to the large amount of signal generated. To speed up the data retrieval process, a multi-sensing technique in which the Lead Zirconate Titanate patches are connected in series and parallel is proposed for structural damage detection. The proposed method is validated using an experimental investigation carried out on a reinforced concrete beam embedded with smart Lead Zirconate Titanate sensor units. The beam is subjected to damage, and the location of damage is identified using conductance signatures obtained from patches sensed individually and through multiplexing. This article proposes an effective methodology for selection of patches to be connected in series/parallel to maximise the efficiency of damage detection. Damage quantification using conventional statistical metrics such as root mean square deviation, mean absolute percentage deviation and cross correlations are found to be ineffective in identifying the location of damage from the multiplexed signatures. In turn, dynamic metrics such as moving root mean square deviation, moving mean absolute percentage deviation and moving cross correlation with overlapped moving blocks of data are proposed in the present work and their ability to detect the damage location from multiplexed signatures is discussed.

In Situ Neutron Diffraction Studies on Poling of the Hard PZT Ceramic PIC181

The poling of hard Lead Zirconate Titanate (PZT) materials is a complex process requiring optimisation of the poling parameters time, temperature, and electric field magnitude. A unique method is presented to monitor the poling process in operando on the unit cell level with neutron diffraction through the analysis of changes in reflection patterns. Diffraction analysis after poling reveals the lattice and domain contributions using poling strain as a measure. This allows for the evaluation of induced dipole alignment and process efficiency. It gives insight into the role of domain wall motions in hard PZT ceramics and how they are affected by poling parameters. Additionally, a poled sample is cycled bipolar and analyzed. It shows a strongly asymmetric strain hysteresis with major contributions from domain wall motions in the tetragonal phase. Macroscopically measured hysteresis loops verify the findings from diffraction. The present work contributes to improving poling results, efficiency and saving energy. The diffraction analysis allows a novel investigation method of the poling mechanisms and provides extensive results that give new insights into the material behavior. With a fundamental research method, this work reveals unprecedented details that can be directly applied to the specific application field of poling technology.

Energy harvesting from human foot movement

ABSTRACT Nowadays it has become a prime need to find alternative sources for generating electricity due to the extensive scarcity of energy. Lead Zirconate Titanate materials are one such alternative source having piezoelectric property where mechanical energy can be converted into electrical energy due to pressure. Present work aims at harvesting electrical energy by human footsteps and the smart use of these type material properties in public gathering situations for efficient generation of electricity. In this research paper, piezoelectric sensor is implanted beneath the shoe to harvest electricity from the vibrations produced due to any human movement that also can be stored in super capacitors for later use. This power generation technique for minor needs is more sustainable, economic and ecological than other existing systems.

Lead-free piezoceramics: Status and perspectives

Abstract

Structure health monitoring using wireless sensor networks on structural elements

This paper presents a system that monitors the health of structural elements in Reinforced Concrete (RC), concrete elements and/or masonry buildings and warn the authorities in case of physical damage formation. Such rapid and reliable detection of impairments enables the development of better risk management strategies to prevent casualties in case of earthquake and floods. Piezoelectric (PZT) sensors with lead zirconate titanate material are the preferred sensor type for fracture detection. The developed sensor mote hardware triggers the PZT sensors and collects the responses they gather from the structural elements. It also sends the collected data to a data center for further processing and analysis in an energy-efficient manner utilizing low-power wireless communication technologies. The access and the analysis of the collected data can be remotely performed via a web interface. Performance results show that the fractures serious enough to cause structural problems can be successfully detected with the developed system.

Analytical solutions of thermo-piezoelectric interactions in a solid fiber of polygonal cross-sections immersed in fluid

PurposeThe purpose of this paper is to study the analytical solutions of transversely isotropic thermo-piezoelectric interactions in a polygonal cross-sectional fiber immersed in fluid using the Fourier expansion collocation method.Design/methodology/approachA mathematical model is developed for the analytical study on a transversely isotropic thermo-piezoelectric polygonal cross-sectional fiber immersed in fluid using a linear form of three-dimensional piezothermoelasticity theories. After developing the formal solution of the mathematical model consisting of partial differential equations, the frequency equations have been analyzed numerically by using the Fourier expansion collocation method (FECM) at the irregular boundary surfaces of the polygonal cross-sectional fiber. The roots of the frequency equation are obtained by using the secant method, applicable for complex roots.FindingsFrom the literature survey, it is evident that the analytical formulation of thermo-piezoelectric interactions in a polygonal cross-sectional fiber contact with fluid is not discussed by any researchers. Also, in this study, a polygonal cross-section is used instead of the traditional circular cross-sections. So, the analytical solutions of transversely isotropic thermo-piezoelectric interactions in a polygonal cross-sectional fiber immersed in fluid are studied using the FECM. The dispersion curves for non-dimensional frequency, phase velocity and attenuation coefficient are presented graphically for lead zirconate titanate (PZT-5A) material. The present analytical method obtained by the FECM is compared with the finite element method which shows a good agreement with present study.Originality/valueThis paper contributes the analytical model to find the solution of transversely isotropic thermo-piezoelectric interactions in a polygonal cross-sectional fiber immersed in fluid. The dispersion curves of the non-dimensional frequency, phase velocity and attenuation coefficient are more prominent in flexural modes. Also, the surrounding fluid on the various considered wave characteristics is more significant and dispersive in the hexagonal cross-sections. The aspect ratio (a/b) of polygonal cross-sections is critical to industry or other fields which require more flexibility in design of materials with arbitrary cross-sections.

4:21 PM Abstract No. 100 Needle-based piezoelectric systems for guided biopsy tissue targeting

US and CT are helpful in guiding needles to tumor tissue; however, accuracy and utility of these imaging tools can be limited when lesions are small. We introduce and test a class of ultrathin, needle-shaped piezoelectric microsystems mounted on biopsy needles to measure modulus. The aim was to test whether this strategy can improve the success rate of percutaneous biopsies. The modulus-sensing probe was constructed with the piezoelectric material lead zirconate titanate (PZT) to provide mechanical actuation (distant from the tip) and sensing (near the tip). Modulus data was obtained by applying voltage to the mechanical actuator and measuring the induced voltage of the sensor. Extensive testing included finite element modeling, in vitro testing in PDMS and agarose, human and rat ex vivo tissues, testing in wide range of normal and neoplastic tissues including recipient livers. Furthermore, correlation of modulus data was made to magnetic resonance elastography results to validate the needle based technology. The study was IRB and IACUC approved. Statistical analysis was performed using Prism software (p< 0.05). In vitro testing of the modulus sensor revealed that sensor signal increases linearly with actuator voltage moduli between 1 and 105 kPa-a linear range compatible with most tissues and organs. Subsequent testing in a wide range of rat in vivo and pathologic ex vivo tissues revealed consistent values with intervariability resulting from intrinsic differences in the stiffness of tissues tested i.e., fat vs muscle. Further testing of fresh recipient livers showed that the needle sensor could distinguish reproducibly tumor tissue from adjacent cirrhotic tissue; the ratios correlated to MRE imaging data. The results indicate a significant difference in modulus between normal and diseased tissue, easily detectable by the sensor and sufficient for use as a guiding signal to aid in needle positioning during biopsies.