High Piezoelectric Performance Research Articles

High Piezoelectric Performance of KNN-Based Ceramics over a Broad Temperature Range through Crystal Orientation and Multilayer Engineering

High Piezoelectric Performance of KNN-Based Ceramics over a Broad Temperature Range through Crystal Orientation and Multilayer Engineering

Publisher’s Note: “High piezoelectric performance and resistivity through a laminated structure design for BiFeO3–BaTiO3 ceramic” [J. Appl. Phys. 135, 084103 (2024)]

Publisher’s Note: “High piezoelectric performance and resistivity through a laminated structure design for BiFeO3–BaTiO3 ceramic” [J. Appl. Phys. 135, 084103 (2024)]

Achieving enhanced piezoelectric properties in BiFeO3-PbTiO3 based ceramics by a synergistic effects of texturing and structure engineering in reactive template grain growth-like process

A synergistic strategy of texturing and structure engineering in reactive template grain growth-like process has been validated on fabricating 0.66Bi0.9Sm0.1FeO3-0.34PbTiO3 piezoelectric ceramics with enhanced properties. A considerable texture degree is successfully obtained by optimizing sintering conditions. The template is fully dissolved into the matrix after sintering, driving a structure transformation from rhombohedral to pseudo-cubic phase. In comparison to its non-textured counterpart, the textured ceramics show a 69 % increase on large-signal piezoelectric coefficient d33* and a 43 % increase on small-signal piezoelectric coefficient d33. Good high temperature piezoelectric performance is also revealed. At 225 °C, the maximum strain and calculated d33* are 0.22 % and 436 pm/V, respectively, which increase by 49 % compared with corresponding parameters at room temperature. The study not only signify a promising strategy to design high performance BFO based functional materials, but also broaden the scope of texture technology in the development of piezoelectric ceramics.

Monolithic three-dimensional hafnia-based artificial nerve system

Artificial nerve systems that mimic the tactile perception ability of human skin could be adopted in the realization of devices for a hyperconnected society, including prosthetic devices, interfaces for virtual reality, and smart sensors. The system consists of a pressure sensor, memory, and signal processing circuit, which possess the capability of generating sensory neuron-like signals. Although technological advances have been made in semiconductor-based memory and transistors over the decades, sensor technology is still relying on micro-electromechanical systems, which are hard to realize miniaturization/high-density and high-performance technology. Here, we demonstrate a monolithic three-dimensional integrated artificial nerve on the basis of ferroelectric HfxZr1-xO2 for use in the core element of neuromorphic memory and a self-powered piezoelectric pressure sensor. The morphotropic phase boundary (MPB) state of hafnia film was formed between orthorhombic and tetragonal phases for high piezoelectric performance. The MPB-based sensor was integrated with self-rectifying ferroelectric tunnel junction memory and silicon-based ring oscillator. We realized a frequency-modulated pulse-like synaptic signal with pressure detection ability over a wide range of 1–50 kPa and a good sensitivity of 0.35 mV/kPa. Also, we demonstrate the real-time frequency-modulated operation of the artificial nerve system by adjusting the functional properties of the hafnia films.

Temperature-Dependent Ferroelectric Properties and Aging Behavior of Freeze-Cast Bismuth Ferrite-Barium Titanate Ceramics.

Lead-free BiFeO3-BaTiO3 (BF-BT) piezoceramics have sparked considerable interest in recent years due to their high piezoelectric performance and high Curie temperature. In this paper, we show how the addition of highly aligned porosity (between 40 and 60 vol %) improves the piezoelectric performance, sensing, and energy harvesting figures of merit in freeze-cast 0.70BiFeO3-0.30BaTiO3 piezoceramics compared to conventionally processed, nominally dense samples of the same composition. The dense and porous BF-BT ceramics had similar longitudinal piezoelectric coefficients (d33) immediately after poling, yet the dense samples were observed to age faster than those of porous ceramics. After 24 h, for example, the porous samples had significantly higher d33 values ranging from 112 to 124 pC/N, compared to 85 pC/N for the dense samples. Porous samples exhibited 3 and 5 times higher longitudinal piezoelectric voltage coefficient g33 and energy harvesting figure of merit d33g33 than dense samples due to the unexpected increase in d33 and decrease in relative permittivity with porosity. Spontaneous polarization (Ps) and remnant polarization (Pr) decrease as the porosity content increased from 37 to 59 vol %, as expected due to the lower volume of active material; however, normalized polarization values with respect to porosity level showed a slight increase in the porous materials relative to the dense BF-BT. Furthermore, the porous ceramics showed improved temperature-dependent strain-field response compared to the dense. As a result, these porous materials show excellent potential for use in high temperature sensing and harvesting applications.

The potential of organic piezoelectric materials for next-generation implantable biomedical devices

Piezoelectricity or piezoelectric effect is a phenomenon by which mechanical energy is converted into electrical energy and vice versa. Piezoelectric effect has been observed in several organic materials. Therefore, in past few years organic piezoelectric materials have received significant research interests in biomedical applications and specifically for fabrication of implantable biomedical devices because of their high piezoelectric performance, excellent biocompatibility and biodegradability, superior mechanical properties, and cheap fabrication process. This article provides a comprehensive review of the recent research progress on organic piezoelectric materials. It extensively covers the piezoelectric properties and preparation methods of different organic piezoelectric materials including amino acids, peptides, proteins, polysaccharides, and polymers (such as PVDF, PLLA, PHB), as well as their representative implantable biomedical device applications namely biosensing, tissue regeneration, and drug delivery. Finally, the article discusses the challenges and future directions of this research field.

High piezoelectric performance and resistivity through a laminated structure design for BiFeO3–BaTiO3 ceramic

BiFeO3–BaTiO3 (BF–BT) ceramics with high Curie temperature and excellent piezoelectric coefficient are expected to be applied in high-temperature piezoelectric sensors and actuators. However, its resistivity decreases rapidly with temperature and impedes its further applications. Moreover, normal methods such as doping modification cannot address this issue. In the present work, bismuth layered Bi4Ti2.93(Zn1/3Nb2/3)0.07O12 (BIT) and perovskite 0.36BiScO3-0.64PbTiO3 (BSPT) ceramics were selected as insulating layers and were, respectively, sintered with 0.7BF–0.3BT ceramics to form laminated ceramics. The heterojunction structures effectively prevent carrier migration, and both resistivities of BIT and BSPT laminated ceramics were increased from 106 to 108−9 Ω cm at 300 °C. In addition, piezoelectric properties of the BSPT-type laminated ceramics are much higher than that of BF–BT ceramics, in which the bipolar strain was increased from 0.04% to 0.1% (4 kV/mm), and d33 was increased from 140 to 237 pC/N. Therefore, designing the insulating layer may be an effective method to realize the high-temperature application for BF–BT ceramics.

Wide-bandwidth immersion ultrasound transducer made of Mn:PIMNT single crystal/epoxy 1–3 composite

The sensitivity and bandwidth of immersion ultrasound transducer directly determine the echo signal intensity and axial resolution of the immersion ultrasonic testing (IUT) equipment. The active piezoelectric material, which is the core part of the transducer, usually operates in a thickness-stretching vibrational mode. Hence, it is necessary for piezoelectric materials to possess high piezoelectric performance. In this work, a relaxor-based ferroelectric Mn:PIMNT single crystal with excellent electromechanical performance (d33=1220 pC/N, g33=37.87×10−3 Vm/N, and k33=90%) was used to fabricate a crystal/epoxy 1–3 composite transducer. The crystal-based transducer has a center frequency of 3 MHz. The −6 dB bandwidth is 111.4%, and the insertion loss is −25.2 dB, which are much better than PZT-5 H 1–3 composite transducer (74.5% and −32.9 dB). Additionally, the imaging test reveals that the 1–3 composite transducer made of Mn:PIMNT single crystal exhibits better axial resolution, which shows a good application prospect in the field of ultrasonic nondestructive testing.

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.

High piezoelectric performance in lead-free (K, Na)NbO3 ceramics under a low driving field

In this work, lead-free (K0.485Na0.485Li0.03)Nb0.8Ta0.2O3 composition was designed to control the orthorhombic-tetragonal phases boundary near the room temperature as confirmed by Rietveld analysis, high-angle annular dark field scanning transmission electron microscopy, and temperature dependent dielectric constant. A comparative study of the direct and indirect synthesis methods was carried out and their functional properties were optimized as a function of sintering temperature (Ts) and dwell time. Here, we achieved a large dynamic piezoelectric constant (d33*) of 510 pm/V under a very low electric field of 15–30 kV/cm. Moreover, an enhanced static piezoelectric constant (d33) of 335 pC/N was obtained with a high Curie temperature (TC) of 315 °C. The large d33 and d33* simultaneously with high TC in a single composition are promising results in lead-free polycrystalline ceramics. The strategic design of this work opens a new door for the possible development of novel functional materials for device applications.

Glycine/alginate-based piezoelectric film consisting of a single, monolithic β-glycine spherulite towards flexible and biodegradable force sensor.

Development of piezoelectric biomaterials with high piezoelectric performance, while possessing excellent flexibility, biocompatibility, and biodegradability still remains a great challenge. Herein, a flexible, biocompatible and biodegradable piezoelectric β-glycine-alginate-glycerol (Gly-Alg-Glycerol) film with excellent in vitro and in vivo sensing performance was developed. Remarkably, a single, monolithic β-glycine spherulite, instead of more commonly observed multiple spherulites, was formed in alginate matrix, thereby resulting in outstanding piezoelectric property, including high piezoelectric constant (7.2 pC/N) and high piezoelectric sensitivity (1.97 mV/kPa). The Gly-Alg-Glycerol film exhibited superior flexibility, enabling complex shape-shifting, e.g. origami pigeon, 40% tensile strain, and repeated bending and folding deformation without fracture. In vitro, the flexible Gly-Alg-Glycerol film sensor could detect subtle pulse signal, sound wave and recognize shear stress applied from different directions. In addition, we have demonstrated that the Gly-Alg-Glycerol film sensor sealed by polylactic acid and beeswax could serve as an in vivo sensor to monitor physiological pressure signals such as heartbeat, respiration and muscle movement. Finally, the Gly-Alg-Glycerol film possessed good biocompatibility, supporting the attachment and proliferation of rat mesenchymal stromal cells, and biodegradability, thereby showing great potential as biodegradable piezoelectric biomaterials for biomedical sensing applications.

Achieving High Piezoelectric Performance across a Wide Composition Range in Tetragonal (Bi,Na)TiO3-BaTiO3 Films for Micro-electromechanical Systems.

Tetragonal (1-x)(Bi,Na)TiO3-xBaTiO3 films exhibit enhanced piezoelectric properties due to domain switching over a wide composition range. These properties were observed over a significantly wider composition range than the morphotropic phase boundary (MPB), which typically has a limited composition range of 1-2%. The polarization axis was found to be along the in-plane direction for the tetragonal composition range x = 0.06-1.0, attributed to the tensile thermal strain from the substrate during cooling after the film formation. A "two-step increase" in remanent polarization against an applied maximum electric field was observed at the high-field region due to the domain switching, and a very high piezoelectric response (effective d33 value, denoted as d33,f) over 220 pm/V was achieved for a wide composition range of x = 0.2-0.5 with high tetragonality, exceeding previously reported values for bulk ceramics. Moreover, a transverse piezoelectric coefficient, e31,f, of 19 C/m2 measured using a cantilever structure was obtained for a composition range of at least 10 atom % (for both x = 0.2 and 0.3). This value is the highest reported for Pb-free piezoelectric thin films and is comparable to the best data for Pb-based thin films. Reversible domain switching eliminates the need for conventional MPB compositions, allowing an improvement in the piezoelectric properties over a wider composition range. This strategy could provide a guideline for the development of environmentally acceptable lead-free piezoelectric films with composition-insensitive piezoelectric performance to replace Pb-based materials with MPB composition, such as PZT.

An interpretable machine learning strategy for pursuing high piezoelectric coefficients in (K0.5Na0.5)NbO3-based ceramics

Perovskite-type lead-free piezoelectric ceramics allow access to illustrious piezoelectric coefficients (d33) through intricate composition design and experimental modulation. Developing a swift and accurate technology for identifying (K, Na)NbO3 (KNN)-based ceramic compositions with high d33 in exceedingly large “compositional” space will establish an innovative research paradigm surpassing the traditional empirical trial-and-error method. Herein, we demonstrate an interpretable machine learning (ML) framework for quick evaluation of KNN-based ceramics with high d33 based on data from published literature. Specifically, a thorough feature construction was carried out from the global and local dimensions to establish tree regression models with d33 as the target property. Subsequently, the feature-property mapping rules of KNN-based piezoelectric ceramics are further optimized through feature screening. To intuitively understand the correlation mechanisms between ML regression targets and features, the sure independence screening and sparsifying operator (SISSO) method was employed to extract the essential descriptors to explain d33. A straightforward descriptor, e(NMB−MVB)⋅ST/(IDA)2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{e}}^{({{NM}}_{\ ext{B}}-{{MV}}_{\ ext{B}})}\\cdot {ST}/{(I{D}_{\ ext{A}})}^{2}$$\\end{document}, consisting of only four easily accessible parameters, can accelerate the evaluation of a series of novel KNN-based ceramics with high d33 while exhibiting strong theoretical interpretability. This work not only provides a tool for the rapid discovery of high piezoelectric performance in KNN-based ceramics but also offers a data-driven route for the design of property descriptors in perovskites.

Enhanced piezo-photocatalytic degradation of organic pollutants by cambered wall lamellar structure of porous tubular g-C3N4

The piezoelectric polarization electric field induced by the non-centrosymmetric triangular holes of g-C3N4 was beneficial to promote the separation and transport of photogenerated carrier. The porous structure of porous tubular g-C3N4 (PTCN) facilitated the absorption of visible light, and its thin and highly extended cambered tube wall lamellae and large specific surface area per unit cross-sectional area facilitated the response of mechanical vibration, thus improving the piezo-photocatalytic performance. The piezo-photocatalytic degradation rates of tetracycline hydrochloride (TCH), ciprofloxacin (CIP), rhodamine B (RhB) and methylene blue (MB) by PTCN were 89%, 51%, 100% and 100% within 30 min, respectively. The yield of H2O2 reached 196.6 μM within 120 min. Photocurrent intensity, finite element simulation, DFT calculation, PFM and free radical quantification experiments were conducted to explain the reason for the high piezoelectric performance of PTCN, and the reason for the higher piezoelectric properties of the tubular structure than the bulk structure was also analyzed in depth. This work filled the research gap of tubular g-C3N4 in piezo-photocatalysis and made up the research gap of the influence of material morphology structure on piezoelectric properties, which provided a new reference and incentive for future piezoelectric photocatalysis research.

High Piezoelectric Performance in Undoped (K,Na)NbO3 Piezoceramics over a Wide Range of Compositions

High Piezoelectric Performance in Undoped (K,Na)NbO₃ Piezoceramics over a Wide Range of Compositions

Reaching High Piezoelectric Performance with Rotating Directional-Field-Aligned PVDF-MoS2 Piezo-Polymer Applicable for Large-Area Flexible Electronics.

Wearable electronics and smart harvesting textile studies require a material system that resists physical stimulation. Such applications require receptive piezo-polymers, and their activation-free preparation that can translate into a continuous large-area film. In this work, it is discussed whether the β-content of piezo-polymer is extended with no use of any activation (i.e. poling), and if the β-content increases, it can be processed over a wide range of surfaces like large-area piezo-film. Such prerequisites within polyvinylidene fluoride-molybdenum disulfide ((PVDF)-MoS2 ) piezo-polymer are thoroughly experimented here to develop a high-performance piezo-film. A MoS2 -mediated PVDF piezo-polymer (termed as P+ -MoS2 ) is introduced, in which no extra β-enhancement activation step is required after spin coating. Experimental results record β ≧ 80% which allows to harvest the voltage and current in the level of ≈17 V and 1 µA, respectively which satisfies 5 V supply voltage requirement of the current microelectronics, and internet of things (IoT). In addition, the capacitors having different capacities are charged using the developed nanogenerator to check its practical applicability. Therefore, the transition process of P-MoS2 to aligned P+ -MoS2 due to passive interlocking (PiL) through rotating directional field is novel and found to be a principal reason for β-enhancement in fabricated devices.

Multifunctional Phra Phrom‐like Graphene‐Based Membrane for Environmental Remediation and Resources Regeneration

AbstractWater and energy shortages are interdependent major worldwide issues that cannot be disregarded. In this work, graphene and BaTiO3 are used to synergistically facilitate the self‐assembly of the β‐phase that is known to induce the piezoelectric properties of the polyvinylidene fluoride (PVDF). This leads to a PVDF/graphene‐BaTiO3 nanocomposite with a unique capability of integrating Phra Phrom‐like four functions into one single asymmetric membrane: i) solar evaporation, ii) power generation, iii) piezo‐photodegradation, and iv) self‐cleaning/monitoring for environmental remediation and resources regeneration. The high heat accumulation capability and piezoelectric performance of the membrane enable it to simultaneously achieve a water production rate of 0.99 kgm−2h−1, in compliance with WHO standards, and a maximum power output of 5.73 Wm−2 in simulated natural environments. Upon subjecting the membranes to environmental cleaning, they not only show a 93% dye degradation rate due to the synergistic effect of piezoelectricity and photocatalysis but also resolve the membrane fouling issue, exhibiting ≈200% resistance change compared to the static state. The successful integration of these four functions into one membrane shows the great potential of this work toward a more sustainable and viable water and energy production approach.

A novel synthesis for the preparation of LiNbO3 powder with high piezoelectric catalytic performance

The traditional method for producing lithium niobate (LiNbO3) powder is based primarily on a solid-state reaction, which has a high energy consumption and low efficiency, requiring long periods of insulation at a high temperature of 1000–1300 °C. In this work, high-purity and high-crystallinity LiNbO3 powder was prepared by using niobium pentoxide (Nb2O5) and lithium fluoride (LiF) at 800 °C for 0.5 h. Interestingly, the prepared LiNbO3 powder demonstrated exceptional piezoelectric catalytic degradation performance and reusability. Under the influence of ultrasonic waves, the LiNbO3 powder achieved complete degradation of Rhodamine B (RhB) within a remarkably short duration of 20 min, with a reaction rate constant of 0.2702 min−1, which was 7.9 times larger than that of commercial LiNbO3 (0.03416 min−1). Furthermore, even after undergoing six degradation cycles, the powder maintained its high degradation efficiency. Active substance trapping and detection experiments revealed the presence of hydroxyl radicals (•OH) and superoxide radicals (•O2−) with potent oxidizing capabilities during the piezoelectric catalysis process, affirming their pivotal roles in the degradation of RhB. The energy-saving and efficient method employed in acquiring LiNbO3 would provide an exciting pathway towards the development of efficient catalysts for organic wastewater treatment, fueled by clean energy sources.

Enhanced piezoelectricity in Pb(Zr0.48Ti0.52)O3-Pb(Mn1/3Sb2/3)O3-Pb(Mg1/3Ta2/3)O3 ceramics through the synergistic effect of defect engineering and lattice distortion

With the increasing demand for industrial applications, it has become crucial to develop special high-power devices that can achieve both high piezoelectric performance and large mechanical quality factor. In this work, we prepared quaternary piezoelectric ceramics, namely (0.95-x)Pb(Zr0.48Ti0.52)O3-xPb(Mg1/3Ta2/3)O3-0.05Pb(Mn1/3Sb2/3)O3 (PZT-PMT-PMS), using a traditional solid-state route. These ceramics exhibit an excellent mechanical quality factor and low loss. By adding an appropriate amount of PMT (x = 0.09), the Mg2+ ions were homogeneously incorporated into the crystal lattice, resulting in a reduction in the content of the tetragonal phase. The formation of (MgZr,Ti′′−VO..) defect dipoles has been studied through Rietveld refinement, which indicates that defect dipoles can hinder domain-wall motion, strengthen the pinning effect, and result in a “harder” performance. Moreover, the high asymmetry caused by large lattice distortion, regulates the piezoelectric properties. The sample shows the optimal performance when the PMT content is 0.09, with d33 = 430 pC/N, Qm = 1740, TC = 258 °C, εr = 1740, tanδ = 0.16 %, Pr = 44.5μC/cm2, and kp = 0.569.

Design and development of a new lead-free BiFeO3-BaTiO3 quenched ceramics for high piezoelectric strain performance

Designing a new high-performance lead-free ceramic has become a cutting-edge research topic due to growing concerns about the toxic nature of lead-based materials. In this work, a convenient strategy of compositional design and domain engineering is applied to the lead-fee BiFeO3-BaTiO3 ceramics which provides a flexible polarization free-energy profile for domain switching. Here, simultaneously enhanced dynamic piezoelectric constant (d33* ≈ 772 pm/V) and a good thermal-stability (Δd33* ≈ 26% over the temperature of 20–180 °C) are achieved with a high Curie temperature (TC) of 432 °C. This high piezoelectric strain performance is collectively attributed to multiple effects such as thermal quenching, suppression of defect charges by donor doping, chemically induced local structure heterogeneity, and electric field-induced phase transition. Furthermore, the addition of BT content decreased octahedral tilting that reduce anisotropy for domain switching and increased in tetragonality (cT/aT) providing a wider polar length for B-site cation displacement, leading to high piezoelectric strain performance. Atomic-resolution transmission electron microscopy and piezoelectric force microscopy combined with X-ray diffraction results strongly support the origin of high piezoelectricity. The high and temperature-stable piezoelectric strain response of this work is superior to those of other lead-free ceramics. The synergistic approach of composition design and the concept present here for the origin of high strain response provides a paradigm for the development of new materials for high-temperature piezoelectric actuator applications.