Piezoelectric Applications Research Articles

Giant spin seebeck effect with highly polarized spin current generation and piezoelectricity in flexible V2SeTeO altermagnet at room temperature

Studies on altermagnetic materials are attracting extensive research efforts owing to their directional dependent spin split band structure. However, it is rare to find reports on the possibility of multifunctionality in altermagnetic systems. Here, we explore the spin dependent transport properties and piezoelectricity of two-dimensional V2SeTeO altermagnet. The V2SeTeO system has a direct band gap of 0.32 eV with a Neel temperature of 510 K. We find a giant effective Seebeck coefficient of 0.64 mV/K at 300 K. This is several times larger than that found in bulk and other two-dimensional materials. Moreover, the effective Seebeck effect is entirely determined by either only spin-up or spin-down component. This feature implies that we can generate highly spin polarized current by temperature gradient at room temperature. We attribute this pure spin current generation to the directional dependent spin split band structure. Along with the spin dependent transport properties, we also find that the Janus V2SeTeO altermagnet shows outstanding flexibility and piezoelectric response with out-of-plane piezoelectric coefficient of d31=0.245pm/V. Overall, we propose that the V2SeTeO altermagnet system exhibits multifunctional physical properties at room temperature, and this can be utilized for potential spintronics and flexible piezoelectric applications simultaneously.

Probabilistic investigation of piezoelectric application for reliability enhancement of composite laminates under edge delamination

In this research a novel probabilistic numerical approach is developed to investigate the effectiveness of piezoelectric (PZT) materials to enhance the reliability of composite laminates under edge delamination onset (EDO). To achieve this, finite element (FE) modeling is employed as an implicit limit state function (LSF) based on a quadratic failure criterion and the concept of critical length. An interactive interface that integrates FE analysis and reliability analysis is then established to execute both processes simultaneously until the convergence condition of the reliability index is satisfied. To validate current FE analysis, the interlaminar stress peaks, and resulting edge delamination probability obtained in this study are compared with available data. Subsequently, the probability of EDO in angle-ply composite laminates under applied longitudinal strain and an applied electric field on the PZT layer is assessed using both the first-order reliability method (FORM) and the second-order reliability method (SORM). The Monte Carlo simulation (MCS) is employed to verify the numerical results. Findings reveal that employment of PZT reduces EDO probability. Moreover, as the applied voltage increases, the critical strain required for definitive EDO also increases, and the positive influence of PZT on enhancing reliability becomes more pronounced, particularly with increased thickness under higher applied strain.

Strain phase equilibria and phase‐field method of ferroelectric polydomain: A case study of monoclinic KxNa1 − xNbO3 thin films

AbstractKnowledge of the thermodynamic equilibria and domain structures of ferroelectrics is critical to establishing their structure–property relationships that underpin their applications from piezoelectric devices to nonlinear optics. Here, we establish the strain condition for strain phase separation and polydomain formation and analytically predict the corresponding domain volume fractions and wall orientations of, relatively low symmetry and theoretically more challenging, monoclinic ferroelectric thin films by integrating thermodynamics of ferroelectrics, strain phase equilibria theory, microelasticity, and phase‐field method. Using monoclinic KxNa1 − xNbO3(0.5 < x < 1.0) thin films as a model system, we establish the polydomain strain–strain phase diagrams, from which we identify two types of monoclinic polydomain structures. The analytically predicted strain conditions of formation, domain volume fractions, and domain wall orientations for the two polydomain structures are consistent with phase‐field simulations and in good agreement with experimental results in the literature. The present study demonstrates a general, powerful analytical theoretical framework to predict the strain phase equilibria and domain wall orientations of polydomain structures applicable to both high‐ and low‐symmetry ferroelectrics and provide fundamental insights into the equilibrium domain structures of ferroelectric KxNa1 − xNbO3 thin films that are of technology relevance for lead‐free dielectric and piezoelectric applications.

Effect of (Mg1/2W1/2)4+ substitution on the structure and electrical properties of Bi4Ti3O12-based high-temperature piezoceramics

Bi4Ti3-x(Mg1/2W1/2)xO12 (BTMW100x) ceramics were synthesized using a direct reaction method combined with a two-step sintering technique. The study systematically investigated the effects of B-site equivalent substitution of (Mg1/2W1/2)4+ on BTMW100x ceramics. The experimental results indicate that an appropriate amount of (Mg1/2W1/2)4+ doping effectively reduces grain thickness, enhances grain distribution uniformity, and decreases the concentration of oxygen vacancies. Consequently, these modifications lead to improved piezoelectric performance while maintaining a high Curie temperature. Notably, Bi4Ti2.95(Mg1/2W1/2)0.05O12 (BTMW5) ceramics exhibit excellent piezoelectric properties and thermal stability, with a piezoelectric coefficient of 23 pC/N and a Curie temperature of 683 °C. These findings suggest that BTMW5 ceramics are promising candidates for high-temperature piezoelectric applications.

High temperature piezoelectric performance of CaZrO3 modified BiScO3-PbTiO3 ceramics

This paper has reported a novel ternary system consisting of (1-x-y) BiScO3-xPbTiO3-yCaZrO3 (yCZ-BS-xPT). The phase structure, microstructure and electrical parameters of the new piezoelectric material at room temperature were studied in detail. The results showed that d33 increased significantly with the increase of CZ content. Combined with the results of phase structure, the MPB of 0.02CZ-BS-xPT is located at x = 0.615, which demonstrates optimum piezoelectric performance (d33 = 470 pC/N，kp = 52.0 %, εr = 1704). At the same time, the in-situ high-temperature electrical parameters were characterized systematically. It is worth noting that the in-situ electrical parameters are more attractive. When the temperature rises from room temperature to 300 °C, the kt and kp of 0.02CZ-BS-0.615 PT decreases by less than 7 % and the kp reaches the maximum of 60.7 % at 200 °C, and remains 49.8 % even at 300 °C. In addition, the in-situ d33 test of 0.005CZ-BS-0.63 PT showed that the d33 of the material increased from room temperature to 424 °C, reaching a maximum of 690 pC/N. From room temperature to 300 °C, the change rate is only 26 %, lower than that of the undoped BS-PT, which is 38.6 %. And the d33* reaches a maximum of 994 p.m./V at 200 °C. The improved in-situ piezoelectric properties of yCZ-BS-xPT ternary system makes it a great candidate for high temperature piezoelectric applications.

Flexible PVDF/BST nanocomposites for mechanical energy harvesting application

The development of a piezoelectric generator (PEG) that exhibits improved durability, stability, and enhanced output performance continues to be a crucial objective for self-powered and wearable electronic devices. In this study, a PEG was constructed using nanocomposite films composed of sol-gel derived Barium Strontium Titanate (BST) filler embedded within a Polyvinylidene fluoride (PVDF) matrix. This flexible polymer matrix structure is selected for its exceptional performance, flexibility, and cost-efficiency, making it ideal for advanced piezoelectric applications. Homogeneous nanocomposite films of PVDF-BST with different proportions of BST were fabricated using the solution casting method. Integrating BST filler into the PVDF matrix significantly enhances the nucleation of the electroactive β-phase, thereby improving the dielectric and ferroelectric properties, which vary according to the volume fraction of BST used. Specifically, the PVDF-BST composite containing 10 % BST (PB10) exhibited the highest electroactive β-phase content at 41.8 %, and demonstrated an energy storage density of 0.8 J/cm³ with an efficiency of 73.9 %. The dielectric constant at room temperature is seen to rise from 23 in pure PVDF to 132 in the PB20 composition at 1 kHz. The open-circuit voltage (Voc) of the PEG was recorded by exerting a periodic force on its surface. Notably, the PB10 variant achieved the highest peak-to-peak open-circuit voltage, reaching 28 V. Additionally, PB10 produced an open-circuit voltage of 22 V in response to finger tapping, highlighting its suitability for applications in touch and pressure sensing.

Application of Piezoelectricity on Running Tracks: A Prototype for the Realization of Sustainable and Efficient Energy

Electrical energy has become a basic necessity today. As the population increases, the amount of electricity demand is also increasing. Therefore, many innovations are needed to meet these needs. One of the innovations in energy harvesting systems is the use of piezoelectricity. This research aims to create a piezoelectric-based running track prototype to produce environmentally friendly electrical energy. The arrangement of piezoelectric sensors used in this research is a parallel circuit. The research method used is the Research and Development method. The test results on the physical activities of walking, running, and jumping show that the prototype system that has been made has worked well and produces a fairly stable electric voltage even though it is still in a small amount. the difference in activity and body weight that presses the prototype produces different electric voltages. For walking activity, the prototype is able to produce a maximum voltage output of 0.83V, running activity has a maximum output of 5.83V and the maximum voltage output of jumping activity is 7.88V. The use of energy is done by storing the energy obtained from the piezoelectric in the battery, which can later be monitored directly by the voltage sensor, bluetooth module, HC-05, and RTC module the data will be sent to the cell phone so that the piezoelectric output voltage can be recorded and monitored. The electrical energy output generated by the piezoelectric is able to charge the battery and switch on the LED light at 2.5 V.

Shockwave induced transformations in novel KNNS-BNKT-BG piezoelectric ceramic and study the impact of shockwave for energy harvesting

We investigate the potential of perovskite KNN ceramics synthesized for high-performance piezoelectric applications via inclusion of BNKT and BiGaO3 into its matrix. The material is engineered to achieve R-O-T phase-boundary which is known for enhanced piezoelectric properties. We analyse the dielectric, ferroelectric characteristics, microstructure through SEM imaging, and piezoelectric behaviour of the pristine ceramic. Subsequently, the material is exposed to controlled 200 shock wave of 2.2 Mach having pressure intensity of about 2 MPa, and its properties are re-evaluated. The results reveal remarkable improvement in piezoelectric coefficient from 270 pC/N to 285 pC/N and enhancement in Curie temperature from 409°C to 446°C due to shock wave treatment. Ceramic microgenerators are fabricated using synthesized KNNS-BNKT-BG ceramics to demonstrate the practical application of the shock-treated material, Its voltage generation capability is evaluated under two conditions: finger tapping with a force of 25 N yielded a voltage of around 24V and controlled shock wave exposure over the microgenerator at varying distances from the shockwave source yielded maximum voltage of 38V at 3 cm away from the conduit. This investigation aims to optimize the device's performance and assess its suitability for harsh environments where shockwaves are prevalent such as in aerospace and defence.

Extremely low loss and high electrical resistivity in CaBi2Nb2O9 high-temperature piezoelectric ceramic by adding WO3

An appropriate amount of WO3 was added into CaBi2Nb2O9 high-temperature piezoelectric ceramics to improve the dense microstructure and enhance the electrical properties. A portion of W ions can be incorporated into the lattice, resulting in an increase in the lattice distortion and spontaneous polarization. As a result, the ferroelectric and piezoelectric properties of the ceramics are promoted. Additionally, reducing the concentration of oxygen vacancies can increase the resistivity of ceramics and significantly reduce the dielectric loss. The CBNO-0.375 wt% WO3 sample shows a large piezoelectric coefficient of 17.1 pC/N, a high remnant polarization of 12.60 µC/cm2, a high TC of 951°C and a large electrical resistivity of 1.86 × 106 Ω·cm at 600 °C. Moreover, the dielectric loss at 600 °C maintains a low value of 0.0076, which is one to two orders of magnitude lower than that of CBNO-based ceramics. Therefore, the method of adding WO3 to construct a CBNO ceramic provides a new strategy for high-temperature piezoelectric applications.

Ferroelectric Polarization Dependent Piezoelectric Hardening in BiFeO3‐BaTiO3 Lead‐Free Ceramics

AbstractThe relation between the improvement of mechanical quality factor (Qm) and internal electric field (Ei) generated during the aging process in lead‐free piezoelectric BiFeO3‐BaTiO3 ceramics is investigated for hard piezoelectric application of power transducers. The change of built‐in Ei depends on the ferroelectric polarization (P) direction during the aging process. For the aging process with P parallel to Ei, Qm and Ei increases but Qm and Ei decreases with P antiparallel to Ei. These results are attributed to the migration of defects by depolarization fields and domain‐wall pinning. This work provides the systematic guidance to develop high‐power piezoelectric transducers with lead‐free ceramics.

Nonlinear electromechanical behaviors of piezoelectric generators with hybrid stiffnesses

In this paper, we introduce a novel two-degree-of-freedom piezoelectric stack hybrid energy harvester including a piezoelectric stack and a set of piezoelectric layers. By incorporating a mechanical stopper and bending leaf springs to achieve frequency up-conversion, we significantly enhance the voltage response of the system. We compare the output performance of prototypes with different spring stiffness. The experimental results show that, at a frequency of 7.8 Hz and an acceleration of 0.8 g, the piezoelectric layers on the lower beam of bending leaf springs generate a peak voltage of 18.92 V, and its instantaneous output power is 32 mW. Meanwhile, the piezoelectric stack produces a peak voltage of 28.56 V, with an instantaneous output power of 3.83 W. Moreover, an increase in the stiffness of the bending leaf spring leads to a decrease in voltage response and power output. This research can facilitate the development of hybrid piezoelectric self-powered applications.

Impact of Gd-doping on structural and electrical properties of 0.4CaBi2Nb2O9-0.6Na0.5Bi2.5Nb2O9 piezoelectric ceramics

This paper focuses on improving the electrical properties of 0.4CaBi2Nb2O9-0.6Na0.5Bi2.5Nb2O9 piezoelectric ceramics through Gd doping. The effect of Gd3+ replacing Ca2+ and Na+ on the 0.4CaBi2Nb2O9-0.6Na0.5Bi2.5Nb2O9 (0.4CBN-0.6NBN) piezoelectric ceramics was subjected to a comprehensive examination. The introduction of Gd3+ has led to the development of a pseudo-tetragonal phase, enhancing the polarization and strengthening the piezoelectric effect. Among the 0.4CBN-0.6NBN-xGd (x = 0.00–0.05) ceramic samples, the sample at x = 0.03 that exhibits the best piezoelectric properties demonstrates a high Curie temperature of 849.7 °C, low dielectric loss (tanδ) of 1.295 % (at 550 °C), high DC resistivity (ρDC) of 1.58 × 108 Ω‧cm (at 500 °C), and a high d33 value of 17.3 pC/N. Following annealing at 800 °C, its d33 retains 94.2 % of its initial value. The improved electrical performances indicate that the Gd-doped 0.4CBN-0.6NBN ceramics hold a great deal of promise for high-temperature piezoelectric applications.

Rare-earth praseodymium-substituted Bi5Ti3FeO15 exhibiting enhanced piezoelectric properties for high-temperature application

Owing to their exceptional piezoelectric effects, piezoelectric materials play a crucial role in high-end technologies and contribute significantly to the national economy. Bismuth layer-structured ferroelectrics (BLSFs) possess high Curie temperatures, making them a focal point of research in high-temperature piezoelectric sensor devices. However, their poor piezoelectric performance and low direct-current (DC) electrical resistivity hinder their effective deployment in high-temperature applications. To overcome these shortcomings, we employed composition optimization by partially substituting bismuth ions with rare-earth praseodymium ions. This approach enhances the piezoelectric performance and improves the DC electrical resistivity by preventing the loss of volatile bismuth ions and stabilizing the bismuth oxide layer (Bi2O2)2+, thereby reducing the concentration of oxygen vacancies. Consequently, we achieved a large piezoelectric constant d33 of 23.5 pC/N in praseodymium-substituted Bi5Ti3FeO15, which is three times higher than that of pure Bi5Ti3FeO15 (7.1 pC/N), along with a high Curie temperature TC of 778 °C. Additionally, the optimal composition of 4 mol% praseodymium-substituted Bi5Ti3FeO15 exhibits good thermal stability of electromechanical coupling characteristics up to 300 °C. This study holds promise for a wide array of high-temperature piezoelectric applications and has the potential to accelerate the development of high-temperature piezoelectric sensor technologies.

Chromium‐substituted bismuth titanate–niobate exhibiting superior piezoelectric performance for high‐temperature applications

AbstractHigh‐temperature piezoelectric ceramics with excellent piezoelectric properties are key materials for high‐temperature piezoelectric devices. In this context, bismuth titanate–niobate (Bi3TiNbO9) is one of the most promising candidates, owing to its high Curie temperature (TC) > 900°C. However, the relatively low piezoelectric response of prototype Bi3TiNbO9 does not satisfy the requirements of high‐precision and high‐sensitivity applications. Herein, chromium‐substituted Bi3TiNbO9 with a nominal composition, Bi3Ti1−xCrxNbO9 (BTN‐100xCr), was prepared using the solid‐state reaction method. Raman spectroscopy and X‐ray diffraction refinements revealed structural distortions induced by the substitution of chromium. Piezo‐response force microscopy and ferroelectric hysteresis loops showed facile polarization reversal and domain wall movement in chromium‐substituted Bi3TiNbO9. The resultant structural distortion and domain wall movement served as intrinsic and extrinsic contributions to the enhancement of the piezoelectric properties, respectively. Consequently, BTN‐1.5Cr exhibits a high piezoelectric constant (d33) of 17.7 pC/N, which is four times that of Bi3TiNbO9 (4.2 pC/N), a high TC of 908°C, and an excellent thermal stability of piezoelectric and electromechanical coupling properties up to 500°C. These results indicate that chromium substitution enhances the high‐temperature piezoelectric properties of Bi3TiNbO9, and chromium‐substituted Bi3TiNbO9 is a promising candidate for high‐temperature piezoelectric applications.

High polarization stability induced by light-activated defect engineering in ferroelectric single crystals

Ferroelectric crystals possess good physical properties, which endow them with great potential in photovoltaic, piezoelectric, and electro-optic applications. The polarization stability of ferroelectric crystals is crucial for device applications, because their performance mostly relies on the engineering of domain structures. In this paper, we show that the polarization stability can be improved through light illumination during poling; the obtained Mn and Fe-doped KTa1-xNbxO3 (Mn&Fe: KTN) single crystals maintained stable single-domain state and excellent electro-optic properties over a 1-year observation period. We propose a possible mechanism for the improved polarization stability through light-activated defect engineering, and also investigate the effect of light illumination on defect states in KTN crystals. Appropriate ions doping and light activation effect are shown to be the effective method for achieving high polarization stability after electric field poling. The light-activated defect engineering promotes the stabilization of polarization structures, which is beneficial for the development of high-performance applications based on ferroelectric crystals.

Multifunctional Experimental Studies of Sm-Ion-Influenced Pseudo-Cubic Morphotropic Phase Boundary Regional BiFeO3-xSrTiO3 Ceramics for High-Temperature Applications

In this manuscript, for the first time, the exploration of the microstructural, ferroelectric, piezoelectric, and dielectric performances are measured for Sm-ion-influenced pseudo-cubic, morphotropic phase boundary (MPB) regional 0.62BiFeO3−0.38SrTiO3:xwt%Sm2O3 (BFST:xSm) ceramics with x = 0–0.25. All the compositions maintained their pseudo-cubic MPB structural stability. The composition of BFST:0.15Sm ceramics exhibited an excellent remnant polarization (Pr) of ~52.11 μC/cm2, an enhanced d33 of 101 pC/N, and the highest relative dielectric constant (ɛr) of ~1152, which are much improved as compared to that of pure BFST ceramics. BFST:0.15Sm ceramics demonstrated a Curie temperature (TC) of 378 °C. Moreover, the composition exhibited high thermal stability for d33 72 pC/N (only a 28% decrease), even at a high temperature of 300 °C. Such outstanding outcomes make BFST:0.15Sm ceramics an ideal applicant for high-temperature piezoelectric applications.

Magnetism, ferroelectricity, and piezoelectricity in bulk α-CrOOH and its monolayer

Multifunctional materials with magnetic, piezoelectric, and ferroelectric properties have a wide range of applications. This study investigates the properties of bulk α-CrOOH and its monolayer using density functional theory. The findings reveal that bulk α-CrOOH exhibits a weak interlayer antiferromagnetism, but has a ferroelectric polarization of 28.45 µC/cm2 and piezoelectric strain constants d33 of 21.69 pm/V, which are comparable to those of the multiferroic material BiFeO3. The monolayer of α-CrOOH is a low-temperature ferromagnetic semiconductor that exhibits robust piezoelectricity. This is because of the intrinsic mirror symmetry breaking in the z-direction, resulting in large out-of-plane piezoelectric coefficients of e31 = 31.914 pC/m and d31 = 0.22 pm/V. These intriguing electric and magnetic properties make polarized bulk and monolayer α-CrOOH potential candidates for piezoelectric and ferroelectric device applications.

Flexural-Mode Piezoelectric Resonators: Structure, Performance, and Emerging Applications in Physical Sensing Technology, Micropower Systems, and Biomedicine.

Piezoelectric material-based devices have garnered considerable attention from scientists and engineers due to their unique physical characteristics, resulting in numerous intriguing and practical applications. Among these, flexural-mode piezoelectric resonators (FMPRs) are progressively gaining prominence due to their compact, precise, and efficient performance in diverse applications. FMPRs, resonators that utilize one- or two-dimensional piezoelectric materials as their resonant structure, vibrate in a flexural mode. The resonant properties of the resonator directly influence its performance, making in-depth research into the resonant characteristics of FMPRs practically significant for optimizing their design and enhancing their performance. With the swift advancement of micro-nano electronic technology, the application range of FMPRs continues to broaden. These resonators, representing a domain of piezoelectric material application in micro-nanoelectromechanical systems, have found extensive use in the field of physical sensing and are starting to be used in micropower systems and biomedicine. This paper reviews the structure, working principle, resonance characteristics, applications, and future prospects of FMPRs.

Boosting piezoelectric response and electric-field induced strain in PMN-PT relaxor ferroelectrics

High-performance piezoelectric materials are essential for diverse electromechanical devices, from actuators to sensors and transducers. Here, we synthesized Ce2O3-doped Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (xCe-PMNT29) solid solutions via conventional solid-state methods. In the x = 2.5 % modified composition, we achieved a notable electrostrain-hysteresis trade-off, enhancing electrostrain (0.2 %), equivalent piezoelectric coefficient d33* (1701 pm V–1 at 3 kV cm–1), and reducing strain hysteresis to 8.1 %. Additionally, direct high-temperature piezoelectric characterizations revealed real-time variations in piezoelectric coefficient (d33) and the actual depolarization temperature, with d33 reaching 859 pC N−1 at 53 °C and planar electromechanical coupling coefficient (kp) exceeding 70 % within 30−85 °C. Leveraging x-ray diffraction (XRD) and piezoelectric force microscopy (PFM), we elucidated synergistic effects between complex nanodomains and local structural heterogeneity, enhancing piezoelectric activity. This study presents a promising approach for improving electromechanical performance and electrostrain in ferroelectrics, with significant potential for practical piezoelectric applications.

Enhancing aircraft crack repair efficiency through novel optimization of piezoelectric actuator parameters: A design of experiments and adaptive neuro-fuzzy inference system approach

This study addressed the critical problem of repairing cracks in aging aircraft structures, a safety concern of paramount importance given the extended service life of modern fleets. Utilized a finite element (FE) method enhanced by the design of experiments (DOE) and adaptive neuro-fuzzy inference system (ANFIS) approaches to analyze the efficacy of piezoelectric actuators in mitigating stress intensity factors (SIF) at crack tips—a novel integration in structural repair strategies. Through simulations, we examined the impact of various factors on the repair process, including the plate, actuator, and adhesive bond size and characteristics. In this work, initially, the SIF estimation used the FE approach at crack tips in aluminum 2024-T3 plate under the uniform uniaxial tensile load. Next, numerous simulations have been performed by changing the parameters and their levels to collect the data information for the analysis of the DOE and ANFIS approach. The FE simulation results have shown that changing the parameters and their levels will result in changing of SIF. Several DOE and ANFIS optimization cases have been performed for the depth analysis of parameters. The current results indicated that optimal placement, size, and voltage applied to the piezoelectric actuators are crucial for maximizing crack repair efficiency, with the ability to significantly reduce the SIF by a quantified percentage under specific conditions. This research surpasses previous efforts by providing a comprehensive parameter optimization of piezoelectric actuator application, offering a methodologically advanced and practically relevant pathway to enhance aircraft structural integrity and maintenance practices. The study innovation lies in its methodological fusion, which holistically examines the parameters influencing SIF reduction in aircraft crack repair, marking a significant leap in applying intelligent materials in aerospace engineering.