Piezoelectric Charge Coefficient Research Articles

Enhanced energy density in piezoelectric PVDF-polymer nanocomposite via multiple mechanism synergetic action

Piezoelectric poly(vinylidene fluoride) (PVDF) polymer exhibits the flexible characteristic, however, a piezo-generator based on the PVDF polymer normally shows low power density because of its low piezoelectric coefficient. Here, we report a fundamental synergistic strategy to prepare PVDF polymer nanocomposite for enhancing electromechanical coupling performance and improving its energy density, including (i) the mechanically directional stress field (MDSF) fabrication of PVDF nanocomposite doped with polar Pb(Zr,Ti)O3 (PZT) ceramic nanoparticles via high-energy ball milling, (ii) introduction of micro-cavities holding polar nanoparticles, and (iii) floating electrode (Ag) films spaced uniformly inside the polymer nanocomposite. The investigations reveal that the MDSF fabrication can induce ordered, chain-shape nanocrystalline fibers with a high β-crystal phase, which makes 42% contribution to the piezoelectricity; while the micro-cavities and floating electrode films after poling exhibit a strong electret effect, which further make 18% and 27% contributions, respectively, to the piezoelectricity. This multiple-mechanism synergistic effect results in a much higher piezoelectric coefficient d33 increased from 4 pC N−1 for a pure PVDF (without bearing a uniaxial stretching) to 33 pC N−1 for the nanocomposite. It further dramatically increases to 228 pC N−1, a giant apparent piezoelectric charge coefficient d33*, for a 3D-printed 7-layer nanocomposite with 360 μm in thickness. An energy harvester (EH) based on the PVDF nanocomposite generates a record high peak power density of 13.2 mW cm−2 and the load power density of 5.46 mW cm−2 under a dynamic pressure of 255 kPa at the frequency of 5 Hz, which is near two orders of magnitude higher than that of a conventional PVDF polymer EHs. The fabricated flexible EH can even directly light up 46 LEDs in real-time or power a blind-man reading system when touching it. This work is of great significance in enlightening future flexible piezoelectronic designs.

Remarkable enhancement in piezoelectric performance of [001] textured Na0.4K0.1Bi0.5TiO3 ceramic

This study explores the dependence of dielectric and piezoelectric properties on the grain morphology, orientation, and electric field in the [001] textured Na0.4K0.1Bi0.5TiO3 (NKBT-T) piezoceramics, fabricated via reactive template grain growth and tape-casting methods. A high degree of [001] texturing with Lotgering factor (f) of ∼0.92 was confirmed by X-ray diffraction, electron backscattered diffraction, and bulk texture measurements. A large average plate length of ∼8.5 ± 1 μm with an aspect ratio of ∼11 was achieved in NKBT-T ceramic. An extremely large value of piezoelectric voltage coefficient (g33) of ∼100×10−3 Vm/N was observed in poled NKBT-T ceramics, originating from a low dielectric constant (∼230) and high piezoelectric charge coefficient (d33 ∼205 pC/N). The transduction coefficient (d33•g33) of NKBT-T ceramic was estimated at ∼20,000 × 10−15 m2N−1 and the mechanical energy harvesting responses of ∼1.8 µA and ∼4 V were recorded in the NKBT-T ceramic-based piezoelectric device.

Elastic Polarization Configuration Coupled with Activity Rattling Space Boosts Energy Harvesting Performance of Lead‐Free Piezoceramic

AbstractPiezoelectric energy harvesting technology is drawing substantial attention as an eco‐friendly method to promote energy transformation, which is at the forefront of current scientific research. However, the difficulties involved in obtaining a stable output voltage (Vout) and a controllable output current density (Iout) represent bottlenecks in the development of piezoelectric energy harvesters (PEHs) for practical applications. Here, a novel strategy that couples elastic polarization configuration with activity rattling space in lead‐free potassium sodium niobate‐based piezoceramics is proposed to break through this barrier. The cantilever beam‐type PEHs assembled using the rationally designed piezoceramic system show a stable Vout (≈22 V) and a controllable Iout over the range from 6.09 to 20.16 µA cm−2, which is sufficient to drive multiple types of wireless sensors that have the same rated voltage but different rated current requirements. These fantastic power generation performances are associated with a stable piezoelectric voltage coefficient (g33), an increasing piezoelectric charge coefficient (d33), and a weakened electrostrictive coefficient (Q33) that stem from polarization configuration optimization in combination with introduction of the activity rattling space design. This work provides a good approach to modulation of the overall performance of piezoelectric materials to meet the demands of advanced PEH applications.

Boosting power output performance of Ba0.85Ca0.15SnxZr0.1-xTi0.9O3 piezoelectric nanogenerators via internal resistance regulation strategy

The piezoelectric charge coefficient (d) and transduction coefficient (d×g) of piezoelectric materials are the key factors that determine the power generation performance of piezoelectric nanogenerators (PENGs). However, it is becoming more difficult to achieve further large improvements in the values of these coefficients. In this work, we propose a new strategy to enhance the output performance of the PENGs by regulating the internal resistance. The internal resistance of Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) PENG was reduced by substituting BaZrO3 with low-resistivity BaSnO3 to obtain high-performance Ba0.85Ca0.15SnxZr0.1-xTi0.9O3 (BCSxZ0.1-xT) PENGs. Although the piezoelectric properties (d and d×g) of BCSxZ0.1-xT deteriorated with increasing Sn content, the power generation capability was markedly improved: the maximum current density (1.27 µA/mm2) and power density (3.09 µW/mm3) were obtained for BCS0.03Z0.07T PENG, reflecting increases of approximately 44% and 18% compared with those values of BCZT PENG, respectively. This work is expected to provide a new way to develop high-performance PENG materials and benefit a wide range of energy harvesting materials.

Enhanced piezoelectric properties in europium-doped lead lanthanum zirconate titanate thin films

This paper investigates the effect of europium (Eu3+) doping on the crystal structure, dielectric and piezoelectric properties of lead lanthanum zirconate titanate (PLZT) thin film. For the present study, Pb0·92(La1-yEuy)0·08(Zr0·52Ti0·48)O3 (PLEZT) compositions with various Eu concentrations (y = 0.0, 0.3, 0.5 and 0.7) were prepared on Si/SiO2/Ti/Pt substrates by chemical solution deposition technique. The X-ray diffraction and Raman spectroscopy studies revealed the structural distortions in PLZT films with Eu doping. The piezoelectric charge coefficient showed significant enhancement with Eu doping for y = 0.5 composition, with good room temperature frequency stability. This improvement in the piezoelectric characteristics of PLEZT films is the result of stronger intrinsic contributions brought in by bigger c/a ratios and higher extrinsic contributions from non-180° domain wall motions.

Investigation on the growth aspects and properties of rubidium hydrogen succinate hydrate single crystal for NLO applications.

A novel semiorganic nonlinear optical single crystal of rubidium hydrogen succinate hydrate (RbHSH) was grown at room temperature using the slow evaporation solution growth technique (SEST) with water as a solvent for nonlinear optical applications. The grown crystal is a triclinic system with a centrosymmetric space group of P1̄ and the compound is stabilized by intramolecular O-H-O and C-H-O bonding. FTIR spectral studies were used to determine the various functional groups present in the material. The optical transmission spectra of the grown crystal demonstrated that a transparency of 89%, with a low cut off wavelength of 240 nm and an energy band gap of 5.21 eV, which is beneficial to developing advanced photonic and optoelectronic devices in the solar blind UV area. The grown crystal is thermally stable upto 174 °C. The electrical properties of RbHSH crystal exhibit low dielectric loss and a low dielectric constant at high frequencies tends to have good optical characteristics. Mechanical analysis demonstrated that the grown crystal shows the normal indentation size effect (ISE) and falls into the hard material category with n = 1.4. Photoconductivity measurements revealed negative photoconductivity. Photoluminescence studies showed that RbHSH emits blue light with a wavelength of 484 nm. Hirshfeld surface analysis was used to analyze intermolecular interactions in the RbHSH crystal. The grown RbHSH crystal piezoelectric charge coefficient have been calculated (d33 = 13 pC N-1) and it is suitable for piezoelectric device applications. Under continuous-wave laser excitation, the third order nonlinear refractive index (n2), absorption coefficient (β), and susceptibility (χ(3)) of the RbHSH crystal were found to be 1.6639 × 10-12 (cm2 W-1), 1.1739 × 10-5 (cm W-1) and 4.86331 × 10-9 esu, respectively.

Effect of excess Bi2O3/PbO on the structural and electrical properties of ternary 0.39Bi(Ni1/2Ti1/2)O3–0.20PbZrO3–0.41PbTiO3 ceramics

The ternary 0.39Bi(Ni1/2Ti1/2)O3–0.20PbZrO3–0.41PbTiO3:x(Bi2O3/PbO) [x = 0, 1, and 2 wt%] ceramics were synthesized via solid-state sintering technique. The impact of excess addition on structural and electrical properties was investigated. PXRD results confirmed the diffusion of excess addition in the 0.39Bi(Ni1/2Ti1/2)O3–0.20PbZrO3–0.41PbTiO3 (BNPZT) lattice, exhibiting the perovskite structure with major rhombohedral (R3c) and minor tetragonal (P4mm) phases. The microstructure of the samples exhibits average grain size distribution (<8 μm). The temperature and frequency-dependent dielectric measurement revealed the relaxor-like ferroelectric behaviour and curie temperature (Tc∼290 °C) observed in BNPZT:1 Pb ceramics. The improved remnant polarization (Pr∼23.47 μC/cm2) and coercive field (Ec∼16.13 kV/cm) were obtained in BNPZT:2 Pb ceramics. The enhanced piezoelectric charge coefficient (d33∼ 496 pC/N) and maximum strain (Smax∼0.12 %) were obtained for BNPZT. The least asymmetric factor (γs) illustrates the lower concentration of inherent defects in BNPZT:1(Bi/Pb) ceramics. This study provides insight into microstructural and electrical properties tuning and paves the way for designing piezoelectric materials.

Tunable d33/d33* for MPB (Ba0.85Ca0.15) (Zr0.1Ti0.9)O3 lead-free piezoceramic by crystallographic texturing approach

The morphotropic phase boundary (MPB) Ba0.85Ca0.15Zr0.10Ti0.90O3 composition is successfully transferred into <001>-textured ceramic having Lotgering factor f-74 % (abbreviated as BCZT-T74) using high aspect ratio BaTiO3-template particles via templated grain growth (TGG) method. The microstructural aspects reveal the distinctive grain growth formation for non-textured (BCZT-NT) and textured (BCZT-T74) ceramics; confirming the proper grain growth formation for textured ceramics. The polarization behavior was tested at 1 Hz, 5 Hz, and 10 Hz electric field frequencies by applying a voltage bias of 1000 V; the BCZT-NT ceramics show more variation in remnant polarization (Pr) as well as maximum polarization (Pmax) peak position while BCZT-T74 ceramics exhibit nearly steady values. The frequency-dependent variation in Pr (i.e. ΔPr) for non-textured and textured BCZT ceramics is ±11.08 % and ±3.25 % respectively in the frequency range 1Hz–10Hz at an applied voltage bias of 1000 V. The bipolar strain-electric field (S-E) butterfly loop evidences the typical piezoelectric nature; for both non-textured and textured BCZT ceramics having the effective piezoelectric strain coefficient d33* of 576 pm/V and 657 pm/V respectively. The BCZT-NT and BCZT-T74 ceramics revealed the average positive strain % values of 0.063 % and 0.1123 % and negative strain % values of 0.003985 % and 0.02281 % respectively at the applied voltage 1000 V functioning at 1Hz. The enhancement in negative strain% for BCZT-T74 ceramics is > 5.70 times higher than BCZT-NT ceramics. The variation in positive strain (i.e. ΔS+ve) and variation in negative strain (i.e. ΔS-ve) for non-textured ceramics is ±11.74 % and ±67.34 %, however, for textured ceramics is only ±3.33 % and ±5.00 % respectively. The BCZT-NT and BCZT-T74 ceramics exhibit the piezoelectric charge coefficient (d33) of 370 pC/N and 520 pC/N (1.4 times that of BCZT-NT ceramics) respectively. The electrostrictive coefficient (Q33) of BCZT-T74 ceramics is 0.039 m4/C2, which is > 2 times higher than BCZT-NT ceramics as well as commercially used toxic PZT-5H ceramics. Therefore, less variation in a strain, as well as polarization nature with varying frequencies and enhancement in piezo properties, suggests the present textured MPB BCZT-T74 ceramics is a promising candidate for piezoelectric devices functioning at the wide range of applied electric field frequencies.

In vivo flexible energy harvesting on porcine heart via highly-piezoelectric PIN–PMN–PT single crystal

One of the main challenges with implantable biomedical devices is the replacement surgeries of depleted batteries for elderly patients. This not only poses medical risks but also results in financial burdens. Consequently, there is a growing need for self-powered in vivo electronics that can convert the biomechanical movements of organs into usable electric energy. Notably, a previously reported in vivo flexible energy harvester generated relatively low current output from a living porcine heart, restricting its ability to operate self-powered electronic devices. In this study, a high current output implantable flexible energy harvester was demonstrated by adopting a highly-piezoelectric single crystal Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) film. The in vivo flexible energy harvester generated a short-circuit output current of 20 µA (corresponding to a current density of 3.08 µA/mm3) from the contraction and relaxation of a porcine heart. This recorded in vivo output current density was attributed to its outstanding piezoelectric charge coefficient of the single crystal PIN-PMN-PT, optimized Ni stressor assisted exfoliation as well as the implementation of a metal-insulator-metal (MIM) structure. Moreover, the flexible energy harvester was also demonstrated as a self-powered cardiac sensor to monitor irregular heartbeats by observing heart rate variations due to drug administration in a porcine heart. Additionally, output performance evaluation was conducted with the chest closed to further assess the feasibility of practical in vivo harvesting. Finally, the single crystal harvester exhibited biocompatibility, showing no signs of cytotoxicity based on cell viability assessments and histological characterizations. These results underscore the potential of the flexible PIN-PMN-PT energy harvesting device as a sustainable power source for self-powered in vivo biomedical electronics.

Piezoelectric ceramics with hierarchical macro- and micro-pore channels for sensing applications

Piezoelectric sensors have attracted increasing attention due to their high sensitivity to forces, pressures and acceleration. The use of porous piezoelectric ceramics with aligned pores formed by freeze casting for sensing application also exhibit advantages due to their combination of a high piezoelectric charge coefficient and low permittivity, which leads to an enhancement in sensor sensitivity compared to dense materials. To fabricate porous materials, the process of direct ink writing (DIW) exhibits superiority in terms of structural design as a result of its ability to provide layer-by-layer and mold-free rapid prototyping. This work provides the first demonstration of the fabrication of lead zirconate titanate (PZT) piezoelectric ceramic scaffolds with sophisticated hierarchical porous structures by simultaneous DIW and freeze casting. The morphology of the porous cells and individual layers of the hierarchical porous PZT ceramic scaffolds were designed by adjusting the rheological properties and optimizing the printing path. The effect of cell structure and number of layers on sensing performance was investigated in detail. Manufactured scaffolds with a sandwich structure exhibited a high output voltage (191 V) under the application of 1 N external force, with a sensitivity of 8.98 V·kPa−1. This work provides a new approach to structural design of piezoelectric sensors to inform future efforts in the fabrication of high-performance piezoelectric ceramics with hierarchical porosity with complex and bespoke geometries.

Organic-Inorganic Rare-Earth Double Perovskite Ferroelectric with Large Piezoelectric Response and Ferroelasticity for Flexible Composite Energy Harvesters.

Hybrid organic-inorganic perovskite (HOIP) ferroelectric materials have great potential for developing self-powered electronic transducers owing to their impressive piezoelectric performance, structural tunability and low processing temperatures. Nevertheless, their inherent brittle and low elastic moduli limit their application in electromechanical conversion. Integration of HOIP ferroelectrics and soft polymers is a promising solution. In this work, a hybrid organic-inorganic rare-earth double perovskite ferroelectric, [RM3HQ]2 RbPr(NO3 )6 (RM3 HQ = (R)-N-methyl-3-hydroxylquinuclidinium) is presented, which possesses multiaxial nature, ferroelasticity and satisfactory piezoelectric properties, including piezoelectric charge coefficient (d33 ) of 102.3 pCN-1 and piezoelectric voltage coefficient (g33 ) of 680×10-3 V m N-1 . The piezoelectric generators (PEG) based on composite films of [RM3HQ]2 RbPr(NO3 )6 @polyurethane (PU) can generate an open-circuit voltage (Voc ) of 30V and short-circuit current (Isc ) of 18µA, representing one of the state-of-the-art PEGs to date. This work has promoted the exploration of new HOIP ferroelectrics and their development of applications in electromechanical conversion 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.

Grain morphology‐dependent dielectric and piezoelectric properties of lead‐free KBT ceramics

AbstractK0.5Bi0.5TiO3 ceramics with cuboid (KBT‐C), rod (KBT‐R), and plate (KBT‐P)‐shaped grains were fabricated via solid‐state reaction and reactive template grain growth (using K2Ti6O13 and K0.5Bi4.5Ti4O15) methods, and the strong dependence of electrical properties on the grain morphology was demonstrated. The average grain sizes of KBT‐R, KBT‐P, and KBT‐C were ∼30 ± 10 μm, 7 ± 1 μm, and 350 ± 50 nm, respectively. While the room temperature dielectric constant decreased for KBT‐R (∼240) and KBT‐P (∼230) from ∼500 for KBT‐C, a significant enhancement in the piezoelectric charge coefficient (d33) was noticed for KBT‐R (∼95 pC/N) and KBT‐P (∼105 pC/N) samples compared to that of KBT‐C ceramic (∼60 pC/N). Accordingly, a large improvement in piezoelectric voltage coefficient (g33) of almost 300% in poled KBT‐R (∼45 × 10−3 Vm/N) and 400% in KBT‐P (∼54 × 10−3 Vm/N) samples over the KBT‐C ceramic was obtained. Interestingly, a significantly lower activation energy (Ea) for KBT‐C (∼0.71 eV) below the temperature of the dielectric maximum (Tm) was noticed compared to KBT‐R (∼1.07 eV) and KBT‐P (∼1.00 eV), suggesting a strong dependence of DC conduction on grain morphology. Furthermore, chronoamperometry measurements confirmed a mixed electronic and ionic conduction at higher temperatures in all samples.

Enhanced Piezoelectric and Dielectric Properties of Lead Free Textured KNN - Epoxy 0-3 Composites

Lead-free textured potassium sodium niobate, (K0.476, Na0.524) NbO3 (KNN), prepared using templated grain growth method (TGG) is used as the filler for the preparation of textured KNN - Epoxy piezoelectric composites. The composites were prepared for 10, 20, 30, 40, 50 volume percent of the filler particles. The prepared composites were polished, electroded and were poled at the rate of 2kV/mm. Lotgering orientation factor (LOF) of 21% is obtained for particles prepared by templated grain growth method. The piezoelectric charge coefficient (d33), dielectric constant and piezoelectric voltage coefficient (g33) were measured. It has been observed that, there is an increase in the piezoelectric and dielectric properties while increasing the KNN filler percentage. The experimentally obtained piezoelectric and dielectric properties have been analyzed and is fitted using the analytical model proposed by Yamada for 0-3 composites for different volume fractions of the constituents.

Investigations on electric properties and domain structures of Nd-doped 0.70Pb(Mg1/3Nb2/3)O3–0.30PbTiO3 relaxor ferroelectric ceramics with high piezoelectric properties

Although rare earth neodymium (Nd) doping is common in Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT) single crystals, it is rarely reported in PMN–PT ceramics. To explore the effect of Nd doping on PMN–PT ceramics, PMN–30PT:xNd3+ (x = 0%, 1%, 2%, and 3%) relaxor ferroelectric ceramics were fabricated using a solid-state method via two-step sintering. An enhanced piezoelectric charge coefficient (d33) of ~870 pC/N and a high piezoelectric strain coefficient (d33⁎) of ~1025 pm/V were achieved for x = 2%. Through Rayleigh analysis of polarization–electric field (P–E) hysteresis loops under small electric fields, it was found that the dielectric property was mainly influenced by the intrinsic contribution (local lattice distortion). Furthermore, by investigating domain configurations, high piezoelectric properties were found to be associated with the domain size reduction and local structural heterogeneity. The results indicate that the PMN–30PT:xNd3+ ceramics is a promising material for electronic devices, and that rare earth Nd doping is an efficient strategy for improving the electronic performance of Pb-based relaxor ferroelectrics.

Structural and electrical properties of PLZT x/65/35 ceramics prepared via mechanical activation method near the morphotropic phase boundary

This paper reports the effect of lanthanum addition on the structural and electrical properties of (Pb1-xLax)(Zr0.65Ti0.35)O3 (PLZT x/65/35, x = 8%,10%,12%,15%) ceramics near the morphotropic phase boundary. Studies were conducted on the PLZT x/65/35 ceramics synthesized via a combinatorial approach of high-energy ball milling (mechanical activation method) followed by Cold Isostatic Pressing (CIP). Due to the application of CIP, PLZT ceramics exhibited improved density and a closely packed microstructure. The SEM analysis showed that PLZT x/65/35 ceramics exhibited an increase in grain size with higher concentrations of La3+ ions. Room temperature X-ray diffraction results revealed the formation of perovskite PLZT phase. The investigation on temperature-dependent dielectric, ferroelectric properties of PLZT x/65/35 ceramics provided experimental confirmation of structures cited in XRD analysis. Among all the compositions, PLZT 8/65/35 samples showed a well saturated, uniform P–E hysteresis loop with a high remanent polarization (Pr). Poled PLZT 8/65/35 samples displayed electric field induced large strains with limited hysteresis. Piezoelectric charge coefficients (d33), electromechanical coupling factors (kp, k33, k31) were determined for poled PLZT x/65/35 ceramics and it was found that PLZT 8/65/35 ceramics reveal properties superior to other compositions. Furthermore, the unipolar strain, Pr, d33, kp, k33, k31 values of PLZT 8/65/35 composition exceeded the previously reported ones for the same composition prepared via sol-gel synthesis technique.

Computation-guided design of flexible piezoelectric composites by optimizing charge-stress transmission

Flexible piezoelectric materials have attracted increasing attention as active components in wearable and flexible electronics, soft robotics and artificial skins or muscles. Although constructing polymer-based composites is becoming a common solution to balance their piezoelectricity and flexibility, challenges associated with the electrical and mechanical mismatch between the polymer matrix and the ceramic fillers remain. Here, taking the piezoelectric composite of lead zirconate titanate-polydimethylsiloxane (PZT/PDMS) as the example, we perform phase-field simulations to spatially and temporally study the electrical and mechanical response. It is found that good connectivity of fillers could provide a load transfer path and break topological restriction of filler morphology on polarization dipoles. Then, we propose an interface design strategy to address the mismatch problem in ‘3–3’ composites, which could greatly enhance the overall piezoelectric response under different modes of compressing, stretching and bending. Finally, we experimentally fabricate high-performance flexible composites with an ultrahigh piezoelectric charge coefficient of 155 pC N−1 and a low Young’s modulus of 63 MPa. This research offers a promising route for designing flexible piezoelectric composites by synergistically regulating connectivity and mismatch problems, which is also expected to guide the optimization of other actuators or sensors related with electromechanical coupling effect.

Rosen-Type Piezoelectric Transformers Based on 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 Ceramic and Doped with Sb2O3.

In this study, the characteristics in the lead-free piezoelectric ceramic 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (0.5BZT-0.5BCT) were investigated to assess its potential for Rosen-type piezoelectric transformers. This piezoelectric ceramic has a piezoelectric charge coefficient d33 of 430 pC/N, an electromechanical coupling factor kp of 49%, a dielectric constant εr of 2836, a remnant polarization Pr of 4.98 μC/cm2, and a coercive electric field Ec of 2.41 kV/cm. Sb2O3 was soft doped with 0.05, 0.1, 0.15, and 0.2 mol%, respectively, and exhibited excellent physical properties at 0.1 mol%. Based on this, a piezoelectric transformer was fabricated and measured, and it showed better output characteristics than pure 0.5BZT-0.5BCT. The amplification ratio (Vout/Vin) was optimized based on the device geometry and properties of the piezoelectric material. Moreover, the output characteristics of the Rosen-type piezoelectric transformer were simulated with the PSpice program. Output values of the fabricated and simulated piezoelectric transformers for the r vibrational frequency were compared and analyzed. Accordingly, the step-up amplification ratios Vout/Vin of the fabricated and simulated devices at the vibrational frequency were compared as well. This piezoelectric transformer could replace silicon steel transformers and be used for the creation of black light and for laptop chargers.

Investigation on growth, spectral, hardness, piezoelectric, contact angle, optical stress and nonlinear optical properties of acid blue 22 dye on ADP single crystals

Reclusive single crystals of ammonium dihydrogen phosphate (ADP) and 0.1[Formula: see text]mol.% Acid Blue 22 dye-incorporated ADP were harvested by using a standard slow cooling mechanism. The skeletal framework of the anisotropic materials was analyzed by using single crystal X-ray diffraction cram. The powder X-ray diffraction examines the phase growth and incorporation of substituents in the crystalline matrices. The incorporation of additives in the system was examined by employing Fourier Transform Infrared Spectroscopy. The analysis of vibrational bands gives insights into the incorporation of additives in ADP crystal system. The transmission window of the specimen and optical bandgap of the given material were analyzed by using UV–Vis spectroscopic analysis. The incorporation of additives to parent crystals was examined by using Scanning Electron Microscope. The quantification of elements in the grown specimen was investigated by using Energy Dispersive X-ray spectroscopy. The mechanical rigidity of the material was inspected by using Vickers microhardness analysis. The piezoelectric charge coefficient of dye-incorporated ADP is higher than pristine ADP. The wettability of the material was identified by contact angle measurements. The optical stress was identified by employing photoelastic measurements. The second- and third-order nonlinear optical properties of pristine and dye-incorporated ADP crystals were investigated by using Kurtz–Perry powder technique and Z-scan technique.

Fine-grained high-performance Ba0.85Ca0.15 Zr0.1Ti0.9O3 piezoceramics obtained by current-controlled flash sintering of nanopowders

Due to environmental concerns, extensive research has been carried out to develop high-performance lead-free piezoceramics capable of replacing commercial lead-based materials. The lead-free (Ba0.7Ca0.3)TiO3 −Ba(Zr0.2Ti0.8)O3 system has emerged as a candidate for room temperature transducer applications because a high piezoelectric charge coefficient is achieved in this system for compositions at the morphotropic phase boundary. However, conventional ceramic processing of these eco-friendly piezoceramics demands high energy consumption because long-lasting, high-temperature heat treatments are needed, which often lead to microstructural degradation that compromises the material reliability. Field-assisted flash sintering has started to be explored since the application of an adequate electric field was shown to significantly reduce the sintering time and temperature, thereby controlling grain growth. In this work, Ba0.85Ca0.15Zr0.1Ti0.9O3 ceramics are obtained by current-controlled flash sintering of mechanosynthesized nanopowders. Exhaustive control of the sintering parameters allows tailoring of the microstructure, which allows dense fine-grained flash-sintered ceramics exhibiting a high electric field-induced strain response to be obtained.