Piezoelectric Performance Research Articles

Enhancing the efficiency of PVDF-based piezoelectric catalysis through water-induced polarization and a micro-nano-composite strategy.

Polyvinylidene fluoride (PVDF)-based piezoelectric catalysts show promise in mechanical force-driven catalysis due to their good biocompatibility, flexibility, and ease of fabrication. However, the catalytic activity of pristine PVDF is limited due to its low piezoelectric phase content (<20%), poor orientation, and low surface carrier concentration. Here, we introduce an efficient PVDF-based composite nano-catalyst (rGO/PVDF) with high piezoelectric catalytic performance. We achieve this by employing a composite strategy that combines nanoscale water-induced polarization with polar functional group-modified graphene (rGO) serving as a nanoelectrode. The nanoscale water polarization effect, together with the two-dimensional planar structure of PVDF and the modified graphene's polar functional groups, effectively induces orientation in the PVDF piezoelectric phase to increase the functional β phase content. As a result, the β phase content and crystallinity of rGO/PVDF reach 95% and 40%, respectively, which are 600% and 170% higher compared to those of pristine PVDF. This enhancement plays a crucial role in endowing the material with strong force-to-electricity conversion characteristics. Additionally, the surface-modified rGO also boosts PVDF's surface carrier concentration and provides active sites for catalysis on the rGO/PVDF composite. Notably, under optimized conditions, our catalyst achieves a ∼99.1% degradation rate of organic pollutants (10 mg L-1) after 12 minutes of sonication at 240 W and maintains a high efficiency of ∼93.7% even at a 10 times higher pollutant concentration (100 mg L-1). Our piezoelectric catalyst also demonstrates efficient H2O2 production at 95.8 mmol grGO-1 h-1, which is ∼9-fold and ∼134-fold higher than those of untreated PVDF and previously reported PVDF-based piezoelectric catalysts, respectively. This work paves the way for the development of highly efficient PVDF-based piezoelectric catalysts, thereby offering valuable insights for the advancement of mechanically driven catalysis in the environmental, energy, and chemical sectors.

Morphotropic phase boundary-based BaTi0.89Sn0.11O3 filler induced polarization tuned P(VDF-TrFE) composites as efficient piezo-tribo hybrid nanogenerators

The BaTi0.89Sn0.11O3 (BTS) filler has shown the ability to greatly tune the dielectric permittivity and ferroelectric polarization of the host P(VDF-TrFE) matrix. This was advantageous both for the piezoelectric and piezo-tribo hybrid energy harvesting performance of the composite system.

Advancing piezoelectric 2D nanomaterials for applications in drug delivery systems and therapeutic approaches.

Precision drug delivery and multimodal synergistic therapy are crucial in treating diverse ailments, such as cancer, tissue damage, and degenerative diseases. Electrodes that emit electric pulses have proven effective in enhancing molecule release and permeability in drug delivery systems. Moreover, the physiological electrical microenvironment plays a vital role in regulating biological functions and triggering action potentials in neural and muscular tissues. Due to their unique noncentrosymmetric structures, many 2D materials exhibit outstanding piezoelectric performance, generating positive and negative charges under mechanical forces. This ability facilitates precise drug targeting and ensures high stimulus responsiveness, thereby controlling cellular destinies. Additionally, the abundant active sites within piezoelectric 2D materials facilitate efficient catalysis through piezochemical coupling, offering multimodal synergistic therapeutic strategies. However, the full potential of piezoelectric 2D nanomaterials in drug delivery system design remains underexplored due to research gaps. In this context, the current applications of piezoelectric 2D materials in disease management are summarized in this review, and the development of drug delivery systems influenced by these materials is forecast.

Unveiling the dynamics of phase-transition from ferroelectric to relaxor behavior in Nd-doped BNT-based lead-free piezoelectric ceramics

Nd-doped BNKBT ceramics show a ferroelectric-to-relaxor transition and high piezoelectric performance, demonstrating a balance between ferroelectric and relaxor phases for improved electrical and structural properties in lead-free applications.

Near stoichiometric lithium niobate crystal with dramatically enhanced piezoelectric performance for high temperature acceleration sensing

Lithium niobate (LN) is a multifunctional crystal with excellent piezoelectric properties, making it a potential candidate for piezoelectric sensing applications. In this study, the mechanism of the discrepancies of piezoelectric...

A flexible piezoelectric/pyroelectric dual-function sensor with high temperature resistance

Most of existing piezoelectric polymers have low glass transition temperatures, so they can only operate at lower temperatures (&lt;150 ℃). Once the operating temperature is exceeded, the piezoelectric performance of the device rapidly decreases. At higher temperatures, dense chain motion can interfere with the orientation of dipoles, thus limiting the development of polymer based high-temperature piezoelectric sensors. High-temperature piezoelectric sensor devices are entirely made of inorganic materials, however, inorganic materials are rigid and can only work under small strains. Therefore, enhancing the temperature resistance of piezoelectric polmers and constructing piezoelectric asymmetric structure are the key to fabricating flexible high-temperature resistant piezoelectric/pyroelectric dual functional sensors. In this study, polyacrylonitrile (PAN) nanofiber film is prepared by electrospinning, and then subjected to heat treatment through programmed temperature control. The effects of the different heat-treatment temperatures on the mechanical and electrical performance of PAN nanofiber film are studied systematically, and the results show that PAN high temperature resistant flexible nanofiber film sensors can be used in high temperature environments (&gt; 500 ℃). Its output performance is improved with the increase of heat treatment temperature (&lt; 260 ℃) and then basically remains unchanged in a temperature range of 260–450 ℃. Finally, the output performance decreases at temperatures higher than 450 ℃. When the heat treatment temperature reaches 260 ℃, the output voltage increases to 10.08 V, and current reaches 2.89 μA. Compared with those of the untreated PAN membranes , its output voltage and current are increase by 3.54 times and 2.83 times, respectively. At the same time, the output of the PAN high temperature resistant flexible nanofiber film sensors is almost unchanged in the high-temperature environments. This is the first time that the pyroelectric effect has been observed in heat-treated PAN nanofiber films and both the open-circuit voltage and short-circuit current have been shown to increase with temperature gradient increasing. Besides, the PAN nanofiber film sensors have durability of more than 5000 cycles at room temperature(25 ℃) even at high temperature (400 ℃). Overall, good flexible, high-temperature resistance, and bifunctional sensing ability make PAN flexible nanofiber film sensors expected to be widely used in high temperature environments such as fire safety, aerospace and other harsh environment.

Morphology-enhanced piezoelectric performance of SnS nanobelts for acetaminophen degradation

This study reveals the enhanced piezoelectric activity of SnS nanobelts with step edges compared to nanobelts/nanoparticles and nanobelts, demonstrating superior catalytic performance for acetaminophen degradation in water.

PVDF/ZnO piezoelectric nanofibers designed for monitoring of internal micro-pressure.

Organic piezoelectric materials are emerging as integral components in the development of advanced implantable self-powered sensors for the next generation. Despite their promising applications, a key limitation lies in their reduced mechanical force-to-electricity conversion efficiency. In this study, we present a breakthrough in the fabrication of soft poly(vinylidene fluoride) (PVDF) organic electrospun piezoelectric nanofibers (OEPNs) with exceptional piezoelectric performance achieved through the incorporation of zinc oxide nanorods (ZnO NR). The inclusion of ZnO NR proved instrumental in augmenting the nanocrystallization of PVDF organic electrospun piezoelectric nanofibers (OEPNs), leading to a highly efficient crystal phase transformation from the α phase to the β/γ phase, serving as superior piezoelectric working dipoles. The resulting PVDF/ZnO NR OEPNs exhibited unparalleled piezoelectric output voltage and current density, particularly noteworthy under a micro-pressure of 1 kPa and a low frequency of 1.5 Hz. Utilizing the obtained PVDF/ZnO NR OEPNs as the piezoelectric working element, we engineered a soft self-powered micro-pressure sensor. This sensor was implanted simultaneously on the cardiovascular walls of the heart and femoral artery in pigs. The sensor demonstrated precise monitoring and recording capabilities for micro-pressure changes during various physiological states, spanning from wakefulness to coma, euthanasia, and notably, the formation of cardiac thrombus. These findings underscore the immense potential of the implantable self-powered sensor for the assessment and diagnosis of pressure-related cardiovascular diseases, such as thrombus and atherosclerosis, during the postoperative recovery phase. This innovative technology offers valuable insights into the dynamic physiological states, paving the way for enhanced postoperative care and management of cardiovascular conditions.

Boosting green EMI shielding and piezoelectric energy generation by defect-driven microstructure manipulation

Doping-induced defects can improve piezoelectric performance by increasing the d33 value of the 5-GLNPS device, while also improving magnetic and dielectric properties to regulate green EMI shielding in segregated PDMS/GNLKN/SWCNT composites.

Facile preparation and charge retention mechanism of polymer-based deformable electret.

Electret materials with high deformability largely extend their applications such as wearable devices and actuators. Meanwhile, the deformability of currently reported electrets is somewhat limited except for a liquid electret that requires synthetic procedures with relatively low product yield. Here, we report a polymer-based electret with infinite deformability, which is simply prepared by corona-discharging on the mixture of two commercially available polymers, i.e., polybutenes (PB) as a liquid polyolefin and polypropylene-graft-maleic anhydride (MPP) as a solute. The charge retention mechanism of the PB/MPP electret was both experimentally and computationally elucidated from the views of molecular and nanoscale structures, and transport properties. Contrary to the ease of the preparation, the charge retention mechanism was complicated. The results of quantum chemical calculations and X-ray scattering indicated that the succinic anhydride polar moieties in MPP act as a charge trap site while how they distribute in the non-polar matrix also matters. Transport property measurements revealed the strong connection between complex viscosity and the relaxation time of the charge decay of the PB/MPP electret. Finally, we fabricated a simple piezoelectric device consisting of the PB/MPP electret. It was demonstrated that the piezoelectric performance of the PB/MPP electret is comparable to that of a conventional solid electret.

Simultaneous achievement of high performance and low sintering temperature in ultra-high Curie temperature La2Ti2O7 ceramics by V2O5 additive

This study uses V2O5 as a sintering aid for La2Ti2O7 ceramics, lowering the sintering temperature, increasing density and resistivity, enhancing piezoelectric performance and maintaining thermal stability.

Preparation of gastrodin modified P(VDF-TrFE)-Eudragit L100-AuNPs nanofiber membranes with piezoelectric property

In recent years, electroactive nerve conduits made from a blend of P(VDF-TrFE) (poly (vinylidene fluoride-trifluoroethylene)) with other materials have shown significant progress. However, research combining P(VDF-TrFE) conduits with drug delivery systems remains sparse. In this study, we developed a novel gastrodin-loaded P(VDF-TrFE)-Eudragit L100-gold nanoparticles (Gas@PT-EL100-AuNPs) nanofiber membrane. Fabricated through electrospinning technique, this composite membrane aimed to investigate the impacts of gastrodin and AuNPs on its properties. Experimental results indicated that the incorporation of gold nanoparticles significantly reduced the fiber diameter of the membrane and enhanced the overall performance by improving hydrophilicity and piezoelectric properties. Specifically, the addition of AuNPs substantially enhanced the piezoelectric performance of the nanofiber membrane. Furthermore, the inclusion of gastrodin not only improved the membrane's hydrophilicity but also enabled effective release of the neuroprotective drug. These findings suggest that the Gas@PT-EL100-AuNPs nanofiber membrane is a novel biomaterial with potential applications in the repair and treatment of nerve injuries.

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.

Dielectric, piezoelectric and energy storage properties of Ca, Zr and Sn doped (Ba1-xCax)(Ti0.85+xZr0.02Sn0.13-x)O3 lead-free ceramics at MPB for 0.05 ≤ x ≤ 0.09

Lead-free piezoceramics based on the (Ba, Ca)(Zr, Ti)O3 (BCZT) system provide outstanding electromechanical characteristics for low-temperature actuation applications, however manufacturing temperatures are a little high. Here, we demonstrate how calcium doping can simultaneously enhance Ba(Zr, Ti, Sn)O3 piezoceramics' electromechanical strain response for the MPB composition(s) with formula (Ba1-xCax)(Ti0.85+xZr0.02Sn0.13-x)O3. The electromechanical, dielectric, and ferroelectric properties of the samples, which were created utilizing solid state synthesis techniques, were all investigated. The sample with the highest d*33 value, 748 pm/V for 0.26 kV/mm and 645 pm/V for 0.62 kV/mm, had 0.070 mol% Ca substituted on the perovskite lattice's A-site, which also demonstrated the best dielectric and piezoelectric performance in the composition range for 0.070 ≤ x ≤ 0.090. The ceramic with electromechanical coefficient (kp) = 44.6 % also displays the greatest values of large electrostrictive coefficients (Q33 ≈ 0.10 m4/C2) that also observed in these Ca, Zr and Sn doped Ba(Zr,Ti, Sn)O3 ceramics.

Novel Sandwich-Structured Flexible Composite Films with Enhanced Piezoelectric Performance.

Piezoelectric poly(vinylidene fluoride) (PVDF) and its copolymers have been widely investigated for applications in wearable electric devices and sensing systems, owing to their intrinsic piezoelectricity and superior flexibility. However, their weak piezoelectricity poses major challenges for practical applications. To overcome these challenges, we propose a two-step synthesis approach to fabricate sandwich-structured piezoelectric films (BaTiO3@PDA/PVDF/BaTiO3@PDA) with significantly enhanced ferroelectric and piezoelectric properties. As compared to pristine PVDF films or conventional 0-3 composite films, a maximum polarization (Pmax) of 11.24 μC/cm2, a remanent polarization (Pr) of 5.83 μC/cm2, and an enhanced piezoelectric coefficient (d33 ∼ 14.6 pC/N) were achieved. Simulation and experimental results have demonstrated that the sandwich structure enhances the ability of composite films to withstand higher poling electric fields in comparison with 0-3 composites. The sandwich-structured piezoelectric films are further integrated into a wireless sensor system with a high force sensitivity of 288 mV/N, demonstrating great potential for movement monitoring applications. This facile approach shows great promise for the large-scale production of composite films with remarkable flexibility, ferroelectricity, and piezoelectricity for wearable sensing devices.

Piezoelectric performance of co-axial electrospun PVDF/TPU nanofiber mats

Energy demand is increasing daily by the improving technology and energy dependent devices such as wearable electronics. Nanogenerators have been studied by the researchers for the last 20 years intensively. Nanofiber and polymer based devices are the most popular ones among the others. A core-shell nanofiber structure was proposed in this study and the ratio of the core to the shell structure was produced. Diameter of the nanofibers and piezoelectric performances were characterized and compared with each other. As result, a maximum voltage of 2.1 V, maximum voltage of 28.28 µA, a maximum power of 31.31 µW, and a maximum power density of 184.17 µW/g.cm-2 were obtained from the maximum ratio of 3:1 (PVDF:TPU).

Investigation on electric properties of 0.57(Bi0.8La0.2)FeO3‐0.43PbTiO3 porous ceramics prepared by burnable plastic sphere method

AbstractIn this study, 0.57(Bi0.8La0.2)FeO3‐0.43PbTiO3 (BLF‐PT) porous ceramics were fabricated by the burnable plastic sphere method using polymethyl methacrylate (PMMA) as a pore forming agent. X‐ray diffraction results reveal that BLF‐PT porous ceramics mixed with tetragonal and rhombohedral phases display the single perovskite structure, changing little for different porosities. Scanning electron microscope images show that porosity of BLF‐PT ceramics increases with the increase of PMMA content with average grain size of 3.2–3.5 μm. Different from the continuous decrease of dielectric constant εr and remnant polarization Pr, piezoelectric constant d33 of BLF‐PT porous ceramics increases initially but then drops with the increase of porosity that reaches to the maximum of 230 pC/N at porosity of 8.5 vol.%. The abnormal enhancement of piezoelectric property is attributed to the unique three‐dimensional grid porous ceramic skeleton and uniformly distributed grain size. Moreover, acoustic impedance Z of BLF‐PT porous ceramic is 11.2 MRayls at porosity of 24.3 vol.% comparing with that of 17.7 MRayls for bulk ceramics, which reduces by 58%. BLF‐PT porous ceramics at lower porosity with enhanced piezoelectric and acoustic matching performances have a great potential in the fields of underwater acoustic transducers and medical ultrasonic diagnosis.

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.

Multifunctional nanoplatform based on tetragonal BaTiO3-Au@polydopamine for computed tomography imaging-guided photothermal synergistic and enhanced piezocatalytic cancer therapy

Non-centrosymmetric tetragonal barium titanate nanocrystals have the potential to serve as piezoelectric catalysts in cancer therapy. When exposed to ultrasound irradiation, BaTiO3 can generate reactive oxygen species with a noninvasive and deep tissue-penetrating approach. However, the application of BaTiO3 in cancer nanomedicine is limited by their biosafety, biocompatibility, and dosage efficiency. To explore the potential application of BaTiO3 in nanomedical cancer treatment, we introduced ultra-small Au nanoparticles onto the surface of BaTiO3 to enhance the piezoelectric catalytic performance. Additionally, we also coated the BaTiO3 with polydopamine to improve their biosafety and biocompatibility. This led to the preparation of a novel multifunctional BaTiO3-based nanoplatform called BTAPs. In vitro and in vivo experiments demonstrated that the incorporation of Au dopants and polydopamine coating successfully improved the piezoelectric catalysis properties and biocompatibility of BaTiO3. Compared with unmodified BaTiO3, BTAPs achieved a similar piezoelectric catalytic effect at a low dose (0.3 mg ml−1 in vitro and 10 mg kg−1 in vivo). Moreover, BTAPs also exhibited enhanced properties in computed tomography imaging and photothermal effects in vivo. Therefore, BTAPs offer valuable insights into the advantages and limitations of piezoelectric catalytic nanomedicine in cancer treatment.

Enhanced thermal and angular velocity-induced hybrid piezoelectric energy harvesting of smart turbine blades

In this study, an approach is proposed to examine hybrid piezoelectric energy harvesting performances from vibrations induced by thermal and angular velocity loads in order to generate energy from the smart turbine blade. In the proposed method, a smart turbine blade is formed by patching the piezoelectric material to the root surface of the turbine blade. A finite element (FE) model of the smart turbine blade is established and then it is validated with a smart blade model in a reference study to test the reliability and accuracy of the FE method. The defined loads are applied to the smart blade to obtain energy from mechanical vibrations induced by thermal and angular velocity loads. Temperature distribution, voltage, and vibration results obtained from energy harvesting analysis under different thermal and angular velocity loads are presented. In order to investigate the energy conversion efficiency of the energy obtained from the system, the energy harvesting circuit is tested in terms of battery discharge times and power output values. The results show that while the maximum energy conversion in the thermally induced smart turbine blade is 11.9 W, a power output of 12.3 W is obtained from the hybrid energy harvesting mechanism under angular velocity and heat flux loads.