Piezoelectric Losses Research Articles

High-field complex parameters characterization of PMN-PT single crystal/epoxy 1–3 composites (φ = 0.4) under a high AC electric field with a varied intensity

It is essential to characterize the high-field properties of piezoelectric composites for their applications in ultrasonic transducers. This study involved the development of an experimental characterization system of piezoelectric impedance spectra and mechanical quality factors under high-field conditions to analyze the properties of PMN-PT piezoelectric single-crystal composites. The impedance spectra and mechanical quality factors of a [001]c-poled 0.69PMN-0.31PT single crystal/epoxy 1–3 composite disk with filling ratio φ = 0.4 under thickness resonance mode were tested at different driving voltages ranging from 1 to 120 Vpp to explore the influence of AC electric field on the material properties. By utilizing a theoretical approach, an evaluation was conducted on the variations in the material properties such as stiffness, permittivity, piezoelectric coefficient, and electromechanical coupling factor, along with respective loss factors. Our results suggest that as the AC electric field increases, the elastic modulus c33D and the mechanical quality factor Qm decrease, while the piezoelectric strain coefficient d33 and the electromechanical coupling factor kt increase. However, the dielectric coefficient ε33X does not show an obvious change in this field range. Furthermore, the elastic loss factor tanϕ, the dielectric loss factor tanδ33′, the piezoelectric loss factor tanθ33′, and the electromechanical coupling loss factor tanχt all increase, indicating that the loss of the piezoelectric composite becomes more evident as the AC electric field grows.

Regulation of domain wall motion in PZT-based ceramics through the introduction of local stress fields

At present, a big challenge exists yet in the piezoelectric ceramic material that high piezoelectric performance and low losses (large Qm and low tanδ) are difficult to achieve concurrently due to the effects of domain switching and domain wall motion on electromechanical properties. In this work, by introducing secondary-phase particles (SnO2 particles) into the hard PZT matrix, we successfully build local stress fields in the ceramic. These local stress fields not only pin the domain and domain wall but also diminish the domain size and increase the domain wall density. The former is in favor of reducing the losses, while the latter is beneficial to promoting the piezoelectric properties. Thus, the optimized piezoelectric properties and losses in the ceramic can be obtained simultaneously. The results show that in the PZT/0.3 wt%SnO2 composite, the mechanical quality factor reaches 2800 and the dielectric loss is only 0.4 %, which are superior to the hard PZT matrix. Meanwhile, the composite ceramic has a high piezoelectric constant of 390 pC/N. These excellent properties will push the development of next-generation high-power electromechanical devices.

Rock drilling performance of rotary ultrasonic tools incorporating PZT piezoceramic and Mn:PIN-PMN-PT piezocrystal

High performance Mn:PIN-PMN-PT piezocrystal material is investigated to understand if its extraordinary properties can replace the traditional hard piezoceramic material for space exploration applications. A bolted Langevin-style ultrasonic drill tool incorporating a pair of Mn:PIN-PMN-PT piezocrystal rings is built to compare with a same configuration ultrasonic drill tool actuated with a pair of hard piezoceramic rings, which are tuned to the first longitudinal mode (L1) at around 20 kHz. From the characterisation results, it is observed that the piezocrystal material presents significantly greater values of relative permittivity, electromechanical coupling coefficient, and piezoelectric charge coefficient than the hard piezoceramic material. Despite these outstanding properties, the piezocrystal driven ultrasonic drill tool shows similar displacement amplitudes to its counterpart. Nonetheless, the impedance magnitude of the piezocrystal driven ultrasonic drill tool at resonance is a magnitude lower than the piezoceramic actuated drill tool, due to the large piezoelectric charge coefficient d33. Ultrasonic rock drilling experiments suggest that the cutting force for sandstone and marble are greatly reduced, but limestone and tuff are less affected.In general, the piezocrystal driven ultrasonic drill tool demonstrates a marginally improved cutting performance than the piezoceramic actuated drill tool, in terms of lower cutting force and motor power consumption, however, the tool wear appears slightly poorer. The research outcome of this paper indicates that the thickness mode of the piezocrystal rings might not be the optimal form of excitation, which could be due to the piezoelectric losses at high excitation levels, so other excitation conditions and vibration modes will need to be explored to fully adopt the extraordinary material properties of the piezocrystal material.

Piezoelectric loss of superconducting microwave resonators integrated with thin-film lithium niobate

Piezoelectric loss of superconducting microwave resonators integrated with thin-film lithium niobate

Loss Determination Techniques for Piezoelectrics: A Review

Nowadays, heat dissipation in electronic devices is one of the serious issues to be resolved in energy and environmental terms. Piezoelectric materials are being utilized in many electronic devices, yet the roadblock toward further miniaturization of piezoelectric devices was identified as heat dissipation. Three types of losses (dielectric, elastic, and piezoelectric) are known to be related to the heat dissipation mechanism of piezoelectric materials, therefore obtaining accurate values of the loss factors is essential for minimizing the heat dissipation of piezoelectric devices. The purpose of this review is to introduce several loss determination techniques for piezoelectric materials. The review starts with brief discussions of the loss factors and of the importance of piezoelectric loss that is related to the antiresonance frequency. Then, the review covers the methods developed by our research group, including High Power Piezoelectric Characterization Systems (HiPoCSTM), the crystallographic orientation method and the partial electrode method, as well as other methods such as the pulse-echo method and computer-based approaches. The review continues with a discussion of piezoelectric device modeling (analytical solution and equivalent circuits) that considers loss factors. Finally, the review provides concluding remarks for addressing current issues and suggesting possible solutions.

Secondary phase softening effect in PZT‐based ceramics by introducing the random electric fields

AbstractIn this work, the random electric fields are constructed in the hard PZT ceramics by adding the ZnO particles as a secondary phase to tune the piezoelectric properties and losses. It is found that the internal bias electric field existing in the hard PZT ceramics has been tuned successfully by the random electric fields and its value reduces with the increased ZnO content. As a consequence, the piezoelectric constant d33 reaches up to 483 pC/N in the PZT/0.75 wt%ZnO composite, which is much higher than that of the hard PZT matrix. In the meantime, the electromechanical quality factor Qm, dielectric loss tan δ, and Curie temperature TC for this composite are about 1109, 0.55%, and 279°C, respectively. The promoted d33 is attributed to the small domain size and reduced internal bias electric field, whereas the low losses (large Qm and low tan δ) can be put down to the still existing nonzero internal bias electric field.

Experimental Verification and Analysis of Vibration Damping Structure of Piezoelectric Ceramic Grain Loss Sensor

In this study, in order to achieve accurate detection of grain loss during the process of combine harvester harvesting, a piezoelectric-based grain loss sensor has been developed. The sensor utilizes a double-layer circular piezoelectric ceramic sheet as its sensitive element. When different grains come into contact with the sensitive element, the piezoelectric effect of the ceramic sheet generates corresponding charges. These charges are then converted into knock charge signals through a charge amplification signal processing circuit that has been specially designed for this purpose. The harsh operating conditions of the sensor, including the presence of significant vibration and noise interference, necessitate the incorporation of a double-layer vibration-damping structure in both the top and bottom layers of the sensor. This paper seeks to analyze the vibration-damping effect of various shock-absorbing materials and structures incorporated into the sensor. This is accomplished by creating a dynamic analysis model that accounts for vibration interference. Furthermore, an experimental bench is established for the purpose of verifying the vibration-damping test results. These tests demonstrate that the utilization of a properly selected vibration-damping structure and materials can effectively eliminate mechanical vibration and noise interference. This, in turn, leads to improved detection accuracy of charge signals after knocking and enhances the overall anti-interference ability of the sensor.

Resonance characteristics and energy losses of an ultra-high frequency ZnO nanowire resonator

An ultra-high frequency (UHF, 300 MHz∼3 GHz) nano mechanical resonator based on defect-free zinc oxide nanowire (ZnO NW) was fabricated through a top-down processing method. Using UHF detection technology based on a lock-in amplifier, through optimized measurement of high-performance equipment, it was detected at room temperature that the ZnO NW resonator could operate at a resonance frequency of nearly 650 MHz and a quality factor Q ≈ 1000∼2500, and its force sensitivity could reach 1 f N·Hz−1/2. The deformation, driving force and first-order resonance frequency of the resonator were calculated using the continuum model and compared with the experimental data. The resonance characteristics of ZnO NW resonators under piezoelectric excitation were analyzed and compared with that under electromagnetic excitation. The effects of various loss factors on the resonance characteristics were analyzed, with emphasis on the generation mechanism of piezoelectric loss, clamping loss and eddy current loss and their effects on quality factor and force sensitivity. The ZnO NWs used in this paper have piezoelectric effect, which is rare in other NWs, and are difficult to be fabricated in a bottom-up manner. And experiments show that for ZnO NWs resonators, piezoelectric excitation has obvious advantages in Q value compared with electromagnetic excitation. Unlike the bottom-up wet etch processing method, the resonant beam structure is well protected by the top-down processing method to reduce internal defects, and the top-down fabrication method is easier to integrate into the fabrication process of integrated circuits, which provides great potential for the applications of NW resonators, such as quantum electromechanical systems and high-frequency signal processing.

Thermal Network Modeling and Thermal Stress Evaluation for a High-Power Linear Ultrasonic Motor

This article presents a high-efficient thermal analysis methodology and outlines a set of useful design guidelines for high-power linear ultrasonic motors. A thermal network modeling technique is introduced to rapidly calculate the temperature rise for a typical high-power linear ultrasonic motor with a V-shaped stator. First, a six-terminal equivalent circuit for Langevin piezoelectric transducer considering the prestress bolt loss and all three losses in piezoelectrics is proposed to calculate the stator loss. Then, the calculated losses along with the friction loss are used as inputs into the developed thermal network model to calculate the temperature rise of critical parts of the motor. Furthermore, an analytical mechanical model combined with the proposed thermal network is established to calculate the temporal–spatial distribution of the stator thermal stress for evaluating its fatigue under the heating-up process. Finally, some experimental measurements and finite-element simulations are conducted to validate the theoretical analyses.

Nonlinear Equivalent Circuit of High-Power Sandwich Piezoelectric Ultrasonic Transducer.

In the theoretical design and analysis of the sandwich piezoelectric ultrasonic transducer, the transducer is considered to be an ideal linear system, where the dielectric, piezoelectric, and mechanical losses are neglected. However, when the transducer is driven at high power, the losses are becoming several times higher comparing them to low signal measurements, and the transducer works in a nonlinear state. In order to predict the performance of the transducer at high power, the nonlinear parameters (complex constants) of the piezoelectric materials are introduced. The corresponding nonlinear equivalent longitudinal wave sound velocity and the nonlinear equivalent longitudinal wavenumber of the piezoelectric ceramics are derived. Then, the nonlinear equivalent circuit (NEC) and the nonlinear resonance frequency equation of the high-power sandwich piezoelectric ultrasonic transducer that related with the losses are deduced. Then, the nonlinear finite element model (NFEM) of the transducer is constructed. The performance parameters of the transducer obtained by the NEC method and the finite element (FE) method are compared with each other, and consistent results have been achieved by two methods. Finally, the contribution of various losses is obtained through theoretical calculation, simulation, and experimental measurement, and the correctness of the theoretical model in this article is verified.

Robust Piezoelectric Coefficient Recovery by Nano-Inclusions Dispersion in Un-Poled PVDF–Ni0.5Zn0.5Fe2O4 Ultra-Thin Films

This work aimed to study the influence of the hybrid interface in polyvinylidene fluoride (PVDF)-based composite thin films on the local piezoelectric response. Our results provide evidence of a surprising contradiction: the optimization process of the β-phase content using nano-inclusions did not correspond to the expected nanoscale piezoelectric optimization. A large piezoelectric loss was observed at the nanoscale level, which contrasts with the macroscopic polarization measurement observations. Our main goal was to show that the dispersion of metallic ferromagnetic nano-inclusions inside the PVDF films allows for the partial recovery of the local piezoelectric properties. From a dielectric point of view, it is not trivial to expect that keeping the same amount of the metallic volume inside the dielectric PVDF matrix would bring a better piezoelectric response by simply dispersing this phase. On the local resonance measured by PFM, this should be the worst due to the homogeneous distribution of the nano-inclusions. Both neat PVDF films and hybrid ones (0.5% in wt of nanoparticles included into the polymer matrix) showed, as-deposited (un-poled), a similar β-phase content. Although the piezoelectric coefficient in the case of the hybrid films was one order of magnitude lower than that for the neat PVDF films, the robustness of the polarized areas was reported 24 h after the polarization process and after several images scanning. We thus succeeded in demonstrating that un-poled polymer thin films can show the same piezoelectric coefficient as the poled one (i.e., 10 pm/V). In addition, low electric field switching (50 MV/m) was used here compared to the typical values reported in the literature (100–150 MV/m).

Improved piezoelectric grain cleaning loss sensor based on adaptive neuro-fuzzy inference system

Improved piezoelectric grain cleaning loss sensor based on adaptive neuro-fuzzy inference system

Loss Characterization of Giant Magnetostrictive Material Under Compressive Stress

The properties of giant magnetostrictive material (GMM) are very sensitive to external compressive stress. Knowledge of these key properties is of essential importance in practical applications such as high-power underwater transducers. Although the parameters of GMM have been extensively studied, characterization and analysis of magnetic, elastic, and piezoelectric losses under different compressive stresses are rarely reported due to the difficulty in experimentally realizing the ideal mechanical free or clamped boundary conditions. In this study, we designed a longitudinal transducer for complex parameters characterization of GMM. We successfully characterize the key three losses in GMM using a multi-degree-of-freedom (MDOF) lumped parameter equivalent circuit model (LECM), meticulously incorporating the surface contact damping, stiffness, and structural losses. MDOF LECM provides a novel idea for loss characterization of GMM under compressive stress. In contrast to prior-art parameters characterization based on the distributed parameter equivalent circuit model (DECM), the proposed characterization based on MDOF LECM shows apparent superiority in terms of global sensitivity. The intensive losses of GMM for ten-time characterizations show high stability and are all positive. Statistical analysis of intensive losses’ dependency on the compressive stress is performed. A longitudinal transducer is designed for experimental verification. Finally, 95% prediction and confidence intervals for the variation trend of the intensive losses in relationship with compressive stress are obtained.

Non-linear losses study in strongly coupled piezoelectric device for broadband energy harvesting

Piezoelectric vibration harvesters with strong electromechanical coupling coefficients have recently been combined with nonlinear electrical techniques capable of tuning their resonant frequency as a solution to provide energy to wireless sensor nodes from wideband vibrations. To be fully competitive, this approach requires piezoelectric generators with strong global electromechanical coupling coefficients k2. However, the presence of non-linear dielectric and piezoelectric losses in piezoelectric materials significantly reduces the power harvested when strongly coupled materials are used. This paper presents a non-linear model that allows for a better consideration of losses for such piezoelectric harvesters. An experimental validation is performed with a strongly coupled cantilever based on a PMN-PT material (k2 = 16 %). The results reveal the importance of considering non-linear dielectric losses. Indeed, we show thanks to the model that neglecting these losses can induce an 18 % overestimation of the harvested power for the presented prototype driven at 0.5 m/s2 amplitude ambient acceleration.

MgNb2 O6 Modified K0.5 Na0.5 NbO3 Eco-Piezoceramics: Scalable Processing, Structural Distortion and Complex Impedance at Resonance.

In this work, piezoceramics of the lead‐free composition K0.5Na0.5NbO3 with an increasing amount of MgNb2O6 (0, 0.5, 1, 2 wt.%) were prepared through conventional solid‐state synthesis and sintered in air atmosphere at 1100 °C. The effect of magnesium niobate addition on structure, microstructure and piezoelectric properties was evaluated. The ceramics maintain the orthorhombic Amm2 phase for all compositions, while an orthorhombic Pbcm secondary phase was found for increasing the concentration of MgNb2O6. Our results show that densification of these ceramics can be significantly improved up to 94.9 % of theoretical density by adding a small amount of magnesium‐based oxide (1 wt.%). Scanning electron microscopy morphology of the 1 wt.% system reveals a well‐packed structure with homogeneous grain size of ∼2.72 μm. Dielectric and piezoelectric properties become optimal for 0.5–1.0 wt.% of MgNb2O6 that shows, with respect to the unmodified composition, either higher piezoelectric coefficients, lower anisotropy and relatively low piezoelectric losses (d33=97 pC N−1; d31=−36.99 pC N−1 and g31=−14.04×10−3 mV N−1; Qp(d31)=76 and Qp(g31)=69) or enhanced electromechanical coupling factors (kp=29.06 % and k31=17.25 %).

Elastic, dielectric, and piezoelectric losses in ceramic-matrix piezocomposites PZT/α-Al2O3

An experimental study of the origin of elastic, dielectric, and piezoelectric losses in ceramic-matrix piezocomposites PZT/α-Al2O3 with different volume concentrations and particle sizes of α-Al2O3 microcrystalline filler was performed. The microstructural features and concentration dependences of the imaginary and real parts of the complex elastic, dielectric, and piezoelectric characteristics of composite piezoelectric elements were studied. The analysis of the obtained dependences was carried out and a physical interpretation of the obtained results was proposed.

Coupled longitudinal-flexural vibration characteristics of a piezoelectric structure with losses

The dynamic characteristics studies of piezoelectric structures usually focus on the single vibration modes such as the longitudinal or the flexural mode, and the losses that cause heat generation and energy waste are generally neglected, which leads to discrepancies compared with experiments. In the present paper, a beam-type piezoelectric structure with four kinds of losses under coupled longitudinal-flexural vibration mode is investigated. In this approach, first, impedance matrix of the structure is obtained based on the motion equation and the electrical-mechanical boundary conditions. Secondly, admittance curves of this piezoelectric structure under different boundary conditions are simulated by the equivalent circuit methods that contain four losses—piezoelectric and dielectric losses, as well as two elastic losses. The simulation results by equivalent circuit methods has good agreement with COMSOL results, which demonstrate the effectiveness of the proposed method.

Determination of anisotropic intensive piezoelectric loss in polycrystalline ceramics

This paper presents an advanced characterization method to obtain anisotropic intensive piezoelectric loss for k31, k33 and k15 mode. By redefining half-power bandwidth, new procedure is suggested with effective k31-k15 geometry using crystallographic approach. Without using low capacitance k33 bar structure, the relative error is not worth consideration. Difficulty of shear mode analysis due to spurious peaks are also resolved with the angled polarization. 1% Nb-doped Pb(Zr0.56Ti0.44)O3 are prepared and analyzed. The shear vibration could be analyzed for A- and B-type resonance where the polarization is angled by 60 and 75° from the applied electric field, respectively. Using suggested method, piezoelectric losses for k31, k33 and k15 vibration mode are obtained as 2.0, 1.3 and 2.2%, respectively. The piezoelectric loss anisotropy could successfully be obtained.

High power piezoelectric characterization system (HiPoCS™)

The bottleneck of the piezoelectric devices in miniaturization is the heat generation owing to the losses. There are three losses in a piezoelectric material; dielectric, elastic and piezoelectric losses. The development of high-power density piezoelectrics is directly relevant to the clarification of the loss mechanisms in such materials. This article describes the characterization methodologies of high-power piezoelectrics, in particular, in determining the three losses separately. There are two categories for the measuring methods: (1) electrical excitation method, and (2) mechanical excitation method. The former is basically admittance/impedance measurement via the output current over the input voltage, further classified into four methods; (a) constant voltage, (b) constant current, (c) constant vibration velocity, and (d) constant input energy. To the contrary, the latter is basically the transient mechanical vibration ring-down measurement under various electrical constraint conditions. The key is to obtain precise values of both mechanical quality factors at resonance QA and at antiresonance QB, regardless of measuring techniques, so that we can determine the piezoelectric loss precisely. The difference of QM between the resonance and antiresonance is originated from the electromechanical coupling factor k2 loss, Depending on the sign of the k2 loss, more efficient driving frequency can be derived rather than the conventional ‘resonance’ frequency.

Electro-elastic analysis of functionally graded piezoelectric variable thickness cylindrical shells using a first-order electric potential theory and perturbation technique

In this research, an analytical solution is presented for the functionally graded piezoelectric cylindrical variable wall thickness that is subjected to mechanical and electrical loading. The non-homogeneous distribution of materials is considered as a power function. The first-order electric potential theory, first-order shear deformation theory, and the energy method are used for extracting the system of governing equations. The solution is accomplished using the matched asymptotic expansion method of the perturbation technique. The effects of non-homogeneous properties on the electromechanical are discussed. Since the intensity of variations in the distribution of properties in functionally graded piezoelectric cylinders can be changed using non-homogeneity constant, the electromechanical behavior of the cylinder can be changed by non-homogeneity constant. By reducing the electric or displacement field in functionally graded piezoelectric cylinders, de-polarization or loss of piezoelectric properties may be averted. Results indicate that non-homogeneity constant has a significant effect on the electromechanical behavior. However, in some cases, the effects of non-homogeneity constant may be neglected. Comparing these results with those predicted by the plane elasticity theory and finite element method shows good agreement. In fact, the present solution can be considered as an objective function to optimize the properties and behavior.