Showing papers on "Lead zirconate titanate published in 2023"

Cracking and Fiber Debonding Identification of Concrete Deep Beams Reinforced with C-FRP Ropes against Shear Using a Real-Time Monitoring System

Abstract: Traditional methods for estimating structural deterioration are generally costly and inefficient. Recent studies have demonstrated that implementing a network of piezoelectric transducers mounted to critical regions of concrete structural members substantially increases the efficacy of the structural health monitoring (SHM) method. This study uses a recently developed electro-mechanical-admittance (EMA)-based SHM system for real-time damage diagnosis of carbon FRP (C-FRP) ropes installed as shear composite reinforcement in RC deep beams. The applied SHM technique uses the frequency response measurements of a network of piezoelectric lead zirconate titanate (PZT) patches. The proposed strengthening methods using C-FRP ropes as ETS and NSM shear reinforcement and the applied anchorage techniques significantly enhanced the strength and the overall performance of the examined beams. The retrofitted beams exhibited increased shear capacity and improved post-peak response with substantial ductility compared with the brittle failure of the non-strengthened specimens. The health condition and the potential debonding failure of the applied composite fiber material were also examined and quantified using the proposed SHM technique. Damage quantification of C-FRP ropes is achieved by comparing and assessing the values of several statistical damage indices. The experimental results demonstrated that the proposed monitoring system successfully diagnosed the region where the damage occurred by providing early warning of the forthcoming critical shear cracking of concrete and C-FRP rope debonding failures. Furthermore, the internal PZT transducers showed sound indications of the C-FRP rope’s health condition, demonstrating a direct correlation with the mechanical performance of the fibers.

Intelligent Cubic-Designed Piezoelectric Node (iCUPE) with Simultaneous Sensing and Energy Harvesting Ability toward Self-Sustained Artificial Intelligence of Things (AIoT).

Abstract: The evolution of artificial intelligence of things (AIoT) drastically facilitates the development of a smart city via comprehensive perception and seamless communication. As a foundation, various AIoT nodes are experiencing low integration and poor sustainability issues. Herein, a cubic-designed intelligent piezoelectric AIoT node iCUPE is presented, which integrates a high-performance energy harvesting and self-powered sensing module via a micromachined lead zirconate titanate (PZT) thick-film-based high-frequency (HF)-piezoelectric generator (PEG) and poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) nanofiber thin-film-based low-frequency (LF)-PEGs, respectively. The LF-PEG and HF-PEG with specific frequency up-conversion (FUC) mechanism ensures continuous power supply over a wide range of 10-46 Hz, with a record high power density of 17 mW/cm3 at 1 g acceleration. The cubic design allows for orthogonal placement of the three FUC-PEGs to ensure a wide range of response to vibrational energy sources from different directions. The self-powered triaxial piezoelectric sensor (TPS) combined with machine learning (ML) assisted three orthogonal piezoelectric sensing units by using three LF-PEGs to achieve high-precision multifunctional vibration recognition with resolutions of 0.01 g, 0.01 Hz, and 2° for acceleration, frequency, and tilting angle, respectively, providing a high recognition accuracy of 98%-100%. This work proves the feasibility of developing a ML-based intelligent sensor for accelerometer and gyroscope functions at resonant frequencies. The proposed sustainable iCUPE is highly scalable to explore multifunctional sensing and energy harvesting capabilities under diverse environments, which is essential for AIoT implementation.

Fiber Reinforced Polymer Debonding Failure Identification Using Smart Materials in Strengthened T-Shaped Reinforced Concrete Beams

Abstract: The favorable contribution of externally bonded fiber-reinforced polymer (EB-FRP) sheets to the shear strengthening of reinforced concrete (RC) beams is widely acknowledged. Nonetheless, the premature debonding of EB-FRP materials remains a limitation for widespread on-site application. Once debonding appears, it is highly likely that brittle failure will occur in the strengthened RC structural member; therefore, it is essential to be alerted of the debonding incident immediately and to intervene. This may not be always possible, particularly if the EB-FRP strengthened RC member is located in an inaccessible area for fast inspection, such as bridge piers. The ability to identify debonding immediately via remote control would contribute to the safer application of the technique by eliminating the negative outcomes of debonding. The current investigation involves the detection of EB-FRP sheet debonding using a remotely controlled electromechanical admittance (EMA)-based structural health monitoring (SHM) system that utilizes piezoelectric lead zirconate titanate (PZT) sensors. An experimental investigation on RC T-beams strengthened for shear with EB-FRP sheets has been performed. The PZT sensors are installed at various locations on the surface of the EB-FRP sheets to evaluate the SHM system’s ability to detect debonding. Additionally, strain gauges were attached on the surface of the EB-FRP sheets near the PZT sensors to monitor the deformation of the FRP and draw useful conclusions through comparison of the results to the wave-based data provided by the PZT sensors. The experimental results indicate that although EB-FRP sheets increase the shear resistance of the RC T-beams, premature failure occurs due to sheet debonding. The applied SHM system can sufficiently identify the debonding in real-time and appears to be feasible for on-site applications.

Dielectric, electric, and piezoelectric properties of three‐phase piezoelectric composite based on castor‐oil polyurethane, lead zirconate titanate particles and multiwall carbon nanotubes

Abstract: The effects of multiwall carbon nanotubes (MWCNTs) on the electrical, dielectric, and piezoelectric properties of the ferroelectric ceramic/castor-oil polyurethane (PUR) composite films were evaluated. The three-phase piezoelectric composites were produced by keeping PUR concentration constant while varying lead zirconate titanate (PZT) volume fractions between 10 and 50 vol.%, at two MWCNT concentrations: above and below percolation threshold. The dc electrical conductivity analysis revealed that small amounts of MWCNTs dispersed within PUR/PZT composite films can significantly improve electrical and piezoelectric properties due to their ability to act as conductive bridges between PZT particles in the samples. Using Jonscher's power law, it was possible to determine that the electrical conduction in ac regime occurs through spatial charge hopping between states located within the piezoelectric composite. Analyzing the piezoelectric properties through the d33 coefficient, it was found that PUR-MWCNT/PZT piezoelectric composite displayed higher d33 values (20 pC/N) in comparison to the PUR/PZT two-phase composite (9.5 pC/N) for all PZT loadings. According to these results, the dispersion of MWCNT nanoparticles influences the poling effectiveness of the PZT particles and increases the d33 coefficient of three-phase piezoelectric composites.

Epitaxial P_b(Z_r,T_i)O₃-Based Piezoelectric Micromachined Ultrasonic Transducer Fabricated on Silicon-On-Nothing (SON) Structure

Abstract: This study reports the fabrication method of a piezoelectric micromachine ultrasonic transducers (pMUTs) using a Silicon on Nothing (SON) structure and a monocrystalline thin film of lead zirconate titanate (PZT). For the SON structure, an array pattern of small hole was fabricated on a (100) Si substrate. Hydrogen annealing was then used to induce Si reflow. As a result, a plate-shaped cavity with a thickness of 0.5 μm was formed under a (100) Si diaphragm of 75 μm diameter. PZT was epitaxially grown on the diaphragm via buffer layers. A pMUT was fabricated and preliminarily characterized. The merits of this fabrication method include single side process, no release and sealing process and compatibility with most of major piezoelectric materials.

A Novel Pipeline Corrosion Monitoring Method Based on Piezoelectric Active Sensing and CNN

Abstract: In this study, a piezoelectric active sensing-based time reversal method was investigated for monitoring pipeline internal corrosion. An effective method that combines wavelet packet energy with a Convolutional Neural Network (CNN) was proposed to identify the internal corrosion status of pipelines. Two lead zirconate titanate (PZT) patches were pasted on the outer surface of the pipeline as actuators and sensors to generate and receive ultrasonic signals propagating through the inner wall of the pipeline. Then, the time reversal technique was employed to reverse the received response signal in the time domain, and then to retransmit it as an excitation signal to obtain the focused signal. Afterward, the wavelet packet transform was used to decompose the focused signal, and the wavelet packet energy (WPE) with large components was extracted as the input of the CNN model to rapidly identify the corrosion degree inside the pipeline. The corrosion experiments were conducted to verify the correctness of the proposed method. The occurrence and development of corrosion in pipelines were generated by electrochemical corrosion, and nine different depths of corrosion were imposed on the sample pipeline. The experimental results indicated that the classification accuracy exceeded 99.01%. Therefore, this method can quantitatively monitor the corrosion status of pipelines and can pinpoint the internal corrosion degree of pipelines promptly and accurately. The WPE-CNN model in combination with the proposed time reversal method has high application potential for monitoring pipeline internal corrosion.

A Review on 3D printed piezoelectric energy harvesters: Materials, 3D printing techniques, and applications

Abstract: The worldwide energy and environmental pollution crisis is caused partly by the rising usage of non-renewable energy sources. Researchers try to find alternative energy systems capable of harvesting energies present in the ambient environment. For more than two decades, piezoelectric energy harvesting devices have been investigated since they represent a viable alternative to traditional power sources for small and low-power electronic devices. The properties of piezoelectric materials and their manufacturing technique significantly impact the performance of a piezoelectric energy harvesting device. Lead zirconate titanate (PZT) is known as the most effective piezoelectric material. However, its rigidity and toxic lead component are major concerns. Due to its high flexibility and excellent piezoelectric capabilities, Poly(vinylidene fluoride) (PVDF), a lead-free piezoelectric material, was proposed as an alternative solution. In addition, in recent years, three-dimensional printing (3DP) techniques, particularly FDM, have received a lot of interest in the piezoelectric energy harvesting field. Moreover, research studies have shown that piezoelectric energy harvesting can be used for many applications, including robotics. This paper aims to provide an overview of current piezoelectric materials and 3DP technology used in the fabrication of piezoelectric energy harvesters (PEHs) and their novel applications.

Simulation and Experiment of Active Vibration Control Based on Flexible Piezoelectric MFC Composed of PZT and PI Layer

Abstract: In order to improve the vibration suppression effect of the flexible beam system, active control based on soft piezoelectric macro-fiber composites (MFCs) consisting of polyimide (PI) sheet and lead zirconate titanate (PZT) is used to reduce the vibration. The vibration control system is composed of a flexible beam, a sensing piezoelectric MFC plate, and an actuated piezoelectric MFC plate. The dynamic coupling model of the flexible beam system is established according to the theory of structural mechanics and the piezoelectric stress equation. A linear quadratic optimal controller (LQR) is designed based on the optimal control theory. An optimization method, designed based on a differential evolution algorithm, is utilized for the selection of weighted matrix Q. Additionally, according to theoretical research, an experimental platform is built, and vibration active control experiments are carried out on piezoelectric flexible beams under conditions of instantaneous disturbance and continuous disturbance. The results show that the vibration of flexible beams is effectively suppressed under different disturbances. The amplitudes of the piezoelectric flexible beams are reduced by 94.4% and 65.4% under the conditions of instantaneous and continuous disturbances with LQR control.

Response Surface Methodology Analysis of Energy Harvesting System over Pathway Tiles

Abstract: This paper presents an experimental analysis of the optimization of PZT-based tiles for energy harvesting. The hardware (actual experiment), PZT-based tiles, were developed using 6 × 6 piezoelectric (PZT—lead zirconate titanate) sensors of 40 mm in diameter on a hard cardboard sheet (300 × 300 mm2). Our experimental analysis of the designed tiles obtained an optimized power of 3.626 mW (85 kg or 0.83 kN using 36 sensors) for one footstep and 0.9 mW for 30 footsteps at high tapping frequency. Theoretical analysis was conducted with software (Design-Expert) using the response surface methodology (RSM) for optimized PZT tiles, obtaining a power of 6784.155 mW at 150 kg or 1.47 kN weight using 34 sensors. This software helped to formulate the mathematical equation for the most suitable PZT tile model for power optimization. It used the quadratic model to provide adjusted and predicted R2 values of 0.9916 and 0.9650, respectively. The values were less than 0.2 apart, which indicates a high correlation between the actual and predicted values. The outcome of the various experiments can help with the selection of input factors for optimized power during pavement design.

Simplified Phenomenological Model for Ferroelectric Micro-Actuator

Abstract: As smart structures are becoming increasingly ubiquitous in our daily life, the need for efficient modeling electromechanical coupling devices is also rapidly advancing. Smart structures are often made of piezoelectric materials such as lead zirconate titanate (PZT), which exhibits strong nonlinear behavior known as hysteresis effect under a large applied electric field. There have been numerous modeling techniques that are able to capture such an effect; some techniques are suitable for obtaining physical insights into the micro-structure of the material, while other techniques are better-suited to practical structural analyses. In this paper, we aim to achieve the latter. We propose a simplified phenomenological macroscopic model of a nonlinear ferroelectric actuator. The assumption is based on the direct relation between the irreversible strain and irreversible electric field, and the consequently irreversible polarization. The proposed model is then implemented in a finite element framework, in which the main features such as local return mapping and the tangent moduli are derived. The outcomes of the model are compared and validated with experimental data. Therefore, the development presented in this paper can be a useful tool for the modeling of nonlinear ferroelectric actuators.

The 0-3 Lead Zirconate-Titanate (PZT)/Polyvinyl-Butyral (PVB) Composite for Tactile Sensing

Abstract: In this study, a 0-3 piezoelectric composite based on lead zirconate-titanate (PZT)/polyvinyl-butyral (PVB) was fabricated and characterized for its potential application in tactile sensing. The 0-3 composite was developed to incorporate the advantages of both ceramic and polymer. The paste of 0-3 PZT–PVB composite was printed using a conventional screen-printing technique on alumina and mylar substrates. The thickness of the prepared composite was approximately 80 μm. After printing the top electrode of the silver paste, 10 kV/mm of DC field was applied at 25 °C, 120 °C, and 150 °C for 10 min to align the electric dipoles in the composite. The piezoelectric charge coefficient of d33 and the piezoelectric voltage coefficient of g33 were improved by increasing the temperature of the poling process. The maximum values of d33 and g33 were 14.3 pC/N and 44.2 mV·m/N, respectively, at 150 °C. The sensor’s sensitivity to the impact force was measured by a ball drop test. The sensors showed a linear behavior in the output voltage with increasing impact force. The sensitivity of the sensor on the alumina and mylar substrates was 1.368 V/N and 0.815 V/N, respectively. The rising time of the sensor to the finger touch was 43 ms on the alumina substrate and 35 ms on the mylar substrate. Consequently, the high sensitivity and fast response time of the sensor make the 0-3 PZT–PVB composite a good candidate for tactile sensors.

Sodium lithium niobate lead-free piezoceramics for high-power applications: Fundamental, progress, and perspective

Abstract: With the capability of interconversion between electrical and mechanical energy, piezoelectric materials have been revolutionized by the implementation of perovskite-piezoelectric-ceramic-based studies over 70 years. In particular, the market of piezoelectric ceramics has been dominated by lead zirconate titanate for decades. Nowadays, the research on piezoelectric ceramics is largely driven by cutting-edge technological demand as well as the consideration of a sustainable society. Hence, environmental-friendly lead-free piezoelectric materials have emerged to replace lead-based Pb(Zr,Ti)O₃ (PZT) compositions. Owing to the inherent high mechanical quality factor (Q_m) and low energy loss, (Li,Na)NbO₃ (LNN) materials have recently drawn increasing attention and brought advantages to high-power piezoelectric applications. Although the crystallographic structures of LNN materials were intensively investigated for decades, the technical strategies for electrical performance are still limited. As a result, the property enhancement appears to have approached a plateau. This review traces the progress in the development of LNN materials, starting from the polymorphism in terms of the crystal structures, phase transitions, and local structural distortions. Then, the key milestone works on the functional tunability of LNN are reviewed with emphasis on involved engineering approaches. The exceptional performance at a large vibration velocity makes LNN ceramics promising for high-power applications, such as ultrasonic welding (UW) and ultrasonic osteotomes (UOs). The remaining challenges and some strategic insights for synergistically engineering the functional performance of LNN piezoceramics are also suggested.

Nonlinear resonant magnetoelectric effect in a circumferentially magnetized ferromagnetic–piezoelectric ring heterostructure

Abstract: The nonlinear magnetoelectric (ME) effect of voltage harmonic generation in a ring heterostructure, comprising a magnetostrictive layer of an amorphous ferromagnet and a piezoelectric layer of lead zirconate titanate is investigated. The structure was circumferentially magnetized with a permanent field H = 0–40 Oe and excited by a circular alternating magnetic field h = 0–3.6 Oe. At the radial acoustic resonance frequency of the structure of ∼54.2 kHz, the first voltage harmonic generation efficiency was 2.9 V/(Oe cm), the second was 0.95 V/(Oe2 cm), and the third was 0.21 V/(Oe3 cm). The absence of demagnetization effects in the ring structure, in comparison with a planar one, leads to a decrease in the optimal biasing magnetic field as well as to a change in the dependence of the second and third ME voltage harmonics on the magnetic field. The discovered nonlinear effect can be used to create frequency doublers.

Fabrication of metal–polymer matching layers to improve some ultrasonic transducers for NDT and calibration

Abstract: Abstract This paper investigates the impact of different matching layers on the ultrasonic transducers’ performance. Matching layers are mostly used to solve the acoustic impedance matching problem between the piezoelectric element and the test specimen. To design good matching layers, we merged the metal–polymer and mass–spring systems. Their thickness was also optimized using the quarter-wavelength approach. Silver, alumina, and copper served as mass components, while parylene served as the polymer spring component. This was the first time to use such matching materials with lead zirconate titanate (PZT) transducers. The transducers’ sensitivity increased, the beam diameter broadened, the signal-to-noise ratio reduced, and the echo-height increased. According to the findings, the developed matching layers were extremely efficient in upgrading PZT transducers, making them ideal for a variety of non-destructive ultrasonic applications such as identifying defects in various materials. In addition, the new developed transducers may be useful in calibration.

Thin, flexible, and biocompatible medical ultrasound array transducer using a sol–gel composite spray technique

Abstract: A thin, flexible, and biocompatible medical ultrasonic transducer was developed using a sol–gel composite spray technique to fabricate a single sheet of piezoelectric material. The careful selection of materials prioritized flexibility, with silicone rubber being chosen for its biocompatibility as the material to be in direct contact with the living body. A porous lead zirconate titanate film with a dielectric constant of 134 was generated, and comb-shaped electrodes were printed on the piezoelectric film to form a 64-channel linear array, which successfully suppressed crosstalk values between adjacent elements and at a distance of two elements to −41.5 and −45.8 dB, respectively. Experiments using string targets achieved a spatial resolution of 2 mm in the lateral direction and 0.68 mm in the axial direction. In an imaging experiment of the carotid artery, the transducer was successful in visualizing the vessel wall before and after the carotid artery vessel.

Excitation mechanism and application of continuous-order mode for one-dimensional thickness vibration.

Abstract: The main method to expand the operating bandwidth of the transducer is by exciting multi-order vibration modes, which develop from the earliest excitation of odd-order modes to the excitation of multi-order continuous modes. However, no detailed theoretical characterization of the excitation mechanism and electroacoustic properties of continuous-order modes has been given. In this paper, the excitation mechanism of continuous-order modes for one-dimensional thickness vibration is studied in detail. From the perspective of analytical characterization, the mathematical and physical conditions of mode excitation are analyzed and extended to continuous-order modes. Partial 1-3 piezocomposite consists of two parts; one part is complete lead zirconate-titanate and the other part is 1-3 composite, which is helpful for exciting continuous-order modes. Based on the excitation mechanism of continuous-order modes, a design method of broadband transducer used of partial 1-3 piezocomposite is proposed, and large bandwidth and good pulse response are obtained. The excitation mechanism of continuous-order modes proposed in this paper provides an idea for the theoretical analysis and design of multi-resonant broadband transducers.

Negative capacitance gate-all-around PZT silicon nanowire with high-K/metal gate MFIS structure for low SS and high I on/I off

Abstract: In the present work, a high-k dielectric hafnium dioxide and lead zirconate titanate (PZT) have been incorporated as a ferroelectric (FE) layer in the gate stack. The Ion/Ioff ratio obtained of the order of 1013, and the subthreshold swing 49.7 mV dec−1 are the most captivating findings of the device which outshines earlier findings. There is a significant improvement in the on-state current (I on) and off-state current (I off). Furthermore, comparatively high value of transconductance (g m) and transconductance generation factor (g m/I d), due to the incorporation of 20 nm PZT NC FE layer, insinuates that the device could be used in low power applications. These enticing findings of the proposed PZT GAA-NCFET nanowire could pave the way for low power devices.

Identification of biomolecule-based electronic materials from a first-principles study of aliphatic amino acids.

Abstract: Biomolecule-based electronic materials can enable health innovations by virtue of their intrinsic bioactivity and physical properties. However, the ultra-wide bandgap and limited piezoelectric properties of most biomaterials prevent them from reaching their full potential. Herein, the electronic structures and electromechanical properties of aliphatic amino acid crystals are investigated based on density functional theory. L-Met is found to be a wide bandgap p-type semiconductor, and the much-reduced bandgap of 2.88 eV is ascribed to the sulphur atoms in L-Met. L-Leu has a shear piezoelectric voltage constant of 2.706 V mN-1 that is over an order of magnitude higher than that of lead zirconate titanate, and good toughness and ductility are also revealed in L-Leu from mechanical property investigations. This study illustrates a computational approach to find smart and multifunctional biomaterials and inspire their growth and applications.

Magnetoelectric Properties of Ni-PZT-Ni Heterostructures Obtained by Electrochemical Deposition of Nickel in an External Magnetic Field

Abstract: This paper studied the influence of external electric and magnetic fields on the magnetoelectric properties of layered structures of metal-piezoelectric-metal. The structures under study had the shape of a square 4 mm wide and were obtained in two steps: first, by the chemical deposition of nickel with a thickness of 0.5 μm, and then by the electrochemical deposition of nickel with a thickness of 50 μm on each side onto a lead zirconate–lead titanate substrate. Electrochemical deposition was carried out without a magnetic field on both non-polarized and polarized ceramics. Electrochemical deposition was also carried out in a magnetic field on a non-polarized and polarized PZT ceramic substrate. A magnetic field of 500 Oe at electrochemical deposition was applied in all cases in the direction of structure polarization. The maximum ME voltage coefficient 300 mV/(cmOe) was obtained at transverse orientation at bias magnetic field near 20 Oe.

Piezoinductive Effect in Piezoelectric Disk With Electrodes Due to Combination of Electromagnetic Induction and Piezoelectricity

Abstract: The effects of mutual conversion of magnetic and electric fields are the basis for elaboration of magnetic field sensors and various electronic devices. Such effects include piezoinductive (PI) effects in piezoelectric-metal structures resulting from a combination of electromagnetic induction and piezoelectricity. In this letter, we study PI effects in a lead zirconate titanate disk with Ag-electrodes. The simple theory for PI effects in piezoelectric disks with electrodes is developed. It is shown experimentally that under the action of an alternating magnetic field h and permanent bias field H applied perpendicular to the disk plane, it generates an alternating voltage. At the frequency of radial acoustic resonance of the disk, the fields conversion efficiency up to 80 V/(Oe cm) was achieved. The efficiency of the fields conversion under PI effect in the disk structure depends linearly on the magnitude of alternating and permanent magnetic fields, which makes it possible to use the effect for elaboration of magnetic field sensors with linear characteristics.