- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Pseudocubic-based polymorphic phase boundary structures and their effect on the piezoelectric properties of (Li,Na,K)(Nb,Sb)O3-SrZrO3 lead-free ceramics
摘要： CuO-added 0.96(LixNa0.5-xK0.5)(Nb1-ySby)O3-0.04SrZrO3 ceramics were sintered at 1020oC for 6 h. Various crystal structures were synthesized in these specimens by controlling the Li2CO3 (x) and Sb2O5 (y) contents: pseudocubic, orthorhombic-pseudocubic polymorphic phase boundary (PPB), tetragonal-pseudocubic PPB, orthorhombic-tetragonal-pseudocubic PPB, and orthorhombic-tetragonal PPB structures. The pseudocubic structure developed in these specimens was similar to the R3m rhombohedral structure instead of the Pm3m cubic structure because the specimens with a pure pseudocubic structure showed good ferroelectric and piezoelectric properties. The piezoelectric properties of the specimens were influenced by their crystal structures. The specimen with the tetragonal-pseudocubic PPB structure showed the best piezoelectric properties because this structure was similar to the tetragonal-rhombohedral morphotropic phase boundary structure developed in Pb(Zr1-xTix)O3-based ceramics. In particular, the specimen with the tetragonal-pseudocubic PPB structure corresponding to x = 0.05 and y = 0.065 showed the largest d33 and kp values of 431 pC/N and 0.43, respectively.
关键词： K)(Nb,Piezoelectric properties,Polymorphic phase boundary structure,Sb)O3-SrZrO3-based lead free piezoelectric ceramics,Pseudocubic structure,Na,(Li
更新于2025-09-23 15:23:52
-
A Low Frequency Vibration Energy Harvester Using ZnO Nanowires on Elastic Interdigitated Electrodes
摘要： This paper presents a low frequency piezoelectric vibration energy harvester using ZnO nanowires on elastic interdigitated electrodes. The interdigitated electrodes are formed using electroplated Ni and have suspended parts at the edges that are elastic and deformable by applying external force. A spherical Ni ball is used as a proof mass, which transforms a low frequency mechanical vibration into the force applied to deform the elastic electrodes. The ZnO nanowires are grown selectively on the electrodes and can generate a piezoelectric potential when the elastic electrodes are deformed by the proof mass activated by the external mechanical vibration. The proposed operation concept is demonstrated using two different types of energy harvesters, which have simple suspended part and cantilever array structures added to the electrodes, respectively. The output voltage of the fabricated harvesters is measured using a vibration exciter at 6 Hz sinusoidal vibration with an acceleration of 0.5 g. Maximum output power of 12.8 pW and 18.8 pW was generated with a load resistance of 1 MΩ for the harvesters using the simple suspended structure and cantilever array, respectively.
关键词： Spherical Proof Mass,Elastic Interdigitated Electrodes,ZnO Nanowires,Low Frequency Piezoelectric Vibration Energy Harvester
更新于2025-09-23 15:23:52
-
Modification of nanocrystalline TiO <sub/>2</sub> coatings with molecularly imprinted TiO <sub/>2</sub> for uric acid recognition
摘要： Combining the surface modification and molecular imprinting technique, a novel piezoelectric sensing platform with excellent molecular recognition capability was established for the detection of uric acid (UA) based on the immobilization of TiO2 nanoparticles onto quartz crystal microbalance (QCM) electrode and modification of molecularly imprinted TiO2 (MIT) layer on TiO2 nanoparticles. The performance of the fabricated biosensor was evaluated, and the results indicated that the biosensor exhibited high sensitivity in UA detection, with a linear range from 0.04 to 45 μM and a limit of detection of 0.01 μM. Moreover, the biosensor presented high selectivity towards UA in comparison with other interferents. The analytical application of the UA biosensor confirmed the feasibility of UA detection in urine sample.
关键词： highly selective detection,uric acid biosensor,piezoelectric sensing,surface modification,molecularly imprinted TiO2
更新于2025-09-23 15:23:52
-
Micromechanical simulation of ferroelectric domain processes at crack tips
摘要： The electromechanical loading situation at cracks in ferroelectric ceramics is essentially affected by domain switching. Under high electrical and/or mechanical external fields, the state of polarization and remanent strains is substantially changed at the crack tip. These irreversible dissipative processes influence the fracture toughness of the cracked ferroelectric material. In the present paper, the micromechanical domain switching processes at the crack tip are studied by numerical simulation and compared with the in situ experimental results obtained by Jones et al. (Acta Mater 55(16):5538–5548, 2007) using X-ray diffraction analyses in synchrotron. Main attention is payed to the spatial distribution of preferred domain orientation in a mechanically loaded compact tension specimen made of a soft tetragonal lead zirconate titanate ceramics. It is found that the mechanically induced favored domain orientation distribution depends on position within the plane of the CT specimen and correlates with projected deviatoric stresses and strains. Some issues concerning shortcomings in the experimental and simulation results are raised and discussed. The outcome of this type of simulations forms the basis for more realistic fracture mechanical evaluations in future.
关键词： Domain switching,Crack tip,Ferroelectric/piezoelectric materials,Fracture,Process zone
更新于2025-09-23 15:23:52
-
Melt Electrowriting of Electroactive Poly(vinylidene difluoride) Fibers
摘要： Poly(vinylidene difluoride) (PVDF) has piezoelectric properties suitable for numerous applications such as flexible electronics, sensing and biomedical materials. In this study, individual fibers with diameters ranging from 17-55 μm were processed using melt electrowriting (MEW). Electroactive PVDF fibers can be fabricated via MEW, while the polymer could remain molten for up to ten hours without noticeable changes in the resulting fiber diameter. MEW processing parameters for PVDF were investigated, including applied voltage, pressure and temperature. A rapid fiber characterization methodology for MEW that automatically determines the fiber diameters from camera images taken of microscope slides was developed and validated. The outputs from this approach followed previous MEW processing trends already identified with different polymers, although overestimation of the < 25 micron fiber diameters was observed. The transformation of the PVDF crystalline phase to the electroactive β-phase – without poling – was confirmed using piezo-force microscopy and revealed that the PVDF fibers possess piezoelectric responses showing d33~19 pm/V.
关键词： melt electrospinning writing,piezoelectric,electrohydrodynamic,piezoresponse force microscopy,3D printing
更新于2025-09-23 15:23:52
-
Preparation of high-quality stress-free (001) aluminum nitride thin film using a dual Kaufman ion-beam source setup
摘要： We proposed and demonstrated a preparation method of (001) preferentially oriented stress-free AlN piezoelectric thin films. The AlN thin films were deposited by a reactive sputtering technique at substrate temperatures up to 330 °C using a dual Kaufman ion-beam source setup. We deposited the AlN on Si (100), Si (111), amorphous SiO2, and a (001) preferentially oriented Ti thin film and compared their crystallographic, optical, and piezoelectric properties. The AlN thin films deposited on the (001) preferentially oriented Ti thin films have the highest crystallographic quality. The stress-free AlN reached a high value of the piezoelectric coefficient d33 = (7.33 ± 0.08) pC·N?1. The properties of the AlN thin film prepared at such low temperatures are suitable for numerous microelectromechanical systems, piezoelectric sensors, and actuators monolithically integrated with complementary metal-oxide-semiconductor signal-processing circuits.
关键词： Ellipsometry,Aluminum nitride thin film,Optical properties,d33 piezoelectric coefficient,Kaufman ion-beam source,Ion-beam sputtering deposition,(001) preferential orientation,X-ray diffraction
更新于2025-09-23 15:23:52
-
An isogeometric analysis to identify the full flexoelectric complex material properties based on electrical impedance curve
摘要： In this paper, we present a new approach to identify all material parameters of flexoelectric materials based on electrical impedance curves. This approach combines an Isogeometric Analysis (IGA) formulation with a gradient-based optimization algorithm using the Method of Moving Asymptotes (MMA). The IGA formulation allows for efficient modeling of flexoelectricity taking advantage of the higher order continuity of IGA. The proposed methodology starts with determining preliminary real parts based on resonant modes in order to avoid local minima which gives the numerical impedance curves close to the experimental impedance curve. The results in the preliminary step are used as initial parameters of the refinement step to simultaneously determine both real and imaginary part by minimizing the difference between pseudo-experimental and numerical impedance curve. Some numerical examples are illustrated to show the good agreement between the numerical and pseudo-experimental impedance curves.
关键词： Complex parameters,Piezoelectric material,Flexoelectric material,Isogeometric analysis
更新于2025-09-23 15:23:52
-
Geometric parameters effect of the atomic force microscopy smart piezoelectric cantilever on the different rough surface topography quality by considering the capillary force
摘要： Nowadays, the atomic force microscopy (AFM) is widely used in the nanotechnology as a powerful nano-robot. The surface topography in Nanoscale is by far one of the most important usages of the AFM device. Hence, in this article, the vibration motion of a piezoelectric rectangular cross-section micro-cantilever (MC) which oscillates in the moist environment has been examined based on the Timoshenko beam theory. After extracting the MC governing equations according to Hamilton's principle, the finite element method has been used to discretize the motion equations. The surface topography has been simulated for various roughness forms in the tapping and non-contact modes by considering the effects of the Van der Waals, capillary and contact forces. Also, the experimental results obtained from the glass surface topography have been simulated. The results illustrate that the time delay in higher natural frequencies in the tapping mode is shorter in comparison with the non-contact mode, especially, for the lower natural frequencies. The sensitivity analysis of the natural frequencies, topography depth and time delay have been simulated. Results indicate that the most effective parameter is the MC length. In the first mode, the first section length has the highest effect on the surface topography time delay, also, in the second vibration mode; the most effective parameter on the time delay is the MC tip length based on the simulation results.
关键词： AFM piezoelectric micro-cantilever,Timoshenko beam,sensitivity analysis,finite element method,topography depth
更新于2025-09-23 15:23:52
-
Enhanced piezoelectric properties and temperature stability of Bi4Ti3O12-based Aurivillius ceramics via W/Nb substitution
摘要： This work provides an effective method of inducing structure distortion, relieving the tetragonal strain of the TiO6 octahedron and decreasing the concentration of oxygen vacancies to improve the piezoelectricity and temperature stability of BIT ceramics. Bi4Ti2.98W0.01Nb0.01O12 possesses an optimum piezoelectric coefficient (d33) of 32 pC/N, a high Tc of 655 °C and a large resistivity of 3 × 106 Ω·cm at 500 °C. The maximum d33 reported here is approximately quadruple than that of pure BIT (~7 pC/N). Moreover, the d33 of W/Nb co-doped BIT and the in-situ temperature stability of the compression-mode sensor present a highly stable characteristic in the range of 25–600 °C. These results imply that W/Nb-modified BIT ceramics is a promising candidate for application at high temperatures of up to 600 °C.
关键词： Bi4Ti3O12,Structure distortion,Piezoelectric properties,Oxygen vacancy,Temperature stability
更新于2025-09-23 15:23:52
-
[SpringerBriefs in Applied Sciences and Technology] Vibration Analysis of Functionally Graded Piezoelectric Actuators ||
摘要： This book has evolved from the passionate desire of the author in using the modern concepts of piezoelectric materials for the design improvement of sensors and actuators. In this connection, the author took up his doctoral studies whose findings have resulted in this book. The initial focus here is on the basic theory, application, and drawbacks of piezoelectric materials. The types of deformation produced in piezoelectric materials due to different piezoelectric effects are reported briefly. Further, the concept of functionally graded material (FGM) used in the design of piezoelectric materials with graded properties is described. The engineering applications of functionally graded piezoelectric materials (FGPMs) are summarized thereafter. In the latter sections, the modal analysis of FGPM actuators is provided. Two types of actuator geometries are taken into consideration—first is beam, and the second is annular plate. The effects of various parameters on the natural frequencies are given in detail. A detailed account of a new numerical technique called the generalized differential quadrature (GDQ), adopted in this book, is also provided. An extension of this technique for the analysis of FGPM structures becomes an important endeavor. The overall focus is on the vibration analysis of FGPM actuators excited under the shear effect using the GDQ method.
关键词： Shear effect,Piezoelectric materials,Functionally graded materials,Vibration analysis,Actuators,Generalized differential quadrature method
更新于2025-09-23 15:23:52