Type Piezoelectric Composites Research Articles

Structure Research of Resistance Shunt Type Piezoelectric Composite and Underwater Sound Absorption Performance Analysis

The high-efficiency sound absorption of underwater sound-absorbing materials under "low frequency" and "wide frequency" conditions has become a hot topic in current research. Underwater semi-active sound absorption can help to improve low frequency sound absorption performance by designing the structure of the piezoelectric composite and the shunt circuits, and it is also advantageous due to its simplicity, compactness, ease of installation, low cost, and high stability. In this paper, a kind of resistance shunt type piezoelectric composite is designed, and its underwater sound absorption performance is analyzed. Theoretical analytical formulas and finite element numerical calculation are used to calculate the electro-elastic constants of the piezoelectric composite. The theoretical model based on the Mason equivalent circuit and transfer matrix theory is used to calculate the sound absorption coefficient. Through the study of 0-3 and 1-3 composites used in the existing research work, it was found that the piezoelectric composite which is suitable for resistance shunt type underwater semi-active sound absorption should have a low longitudinal wave velocity and high electromechanical conversion coefficient. According to this design objective, the structure of the piezoelectric composite has been gradually modified, and finally it is determined that the sparse oblique 2-1-3 composite is an appropriate type of piezoelectric composite. Theoretical calculations and simulation experimental measurement verifies that when the inclination angle is 21 deg and the shunt resistance is 10 kOhm or the inclination angle is 24 deg and the shunt resistance is 10 kOhm, the sound absorption coefficient within the low frequency band 1--3~kHz can be significantly improved.

Hydrostatic piezoelectric properties of 1-3 type piezo-composite with a porous polymer matrix

ABSTRACT Piezoelectric sensors for underwater sonar require high hydrostatic piezoelectric properties (dh, gh and HFOM), and research is being conducted on various types of piezoelectric composites to improve them. In this study, research was conducted to improve the hydrostatic piezoelectric properties of 1–3 type piezoelectric composites using PZT piezoelectric ceramics and polymers. First, the appropriate material and volume fraction of the piezoelectric ceramic were selected through numerical analysis, and then experimental specimens were produced by applying various porosity of the polymer matrix. As a result of the experiment, it was confirmed that dh increased by 75% as the porosity of the polymer matrix increased. This phenomenon was analyzed to be caused by a change in elastic modulus. In addition, gh and HFOM also increased by 70% and 210% as the porosity of the polymer matrix increased. These results experimentally demonstrated that controlling the porosity of the polymer matrix is useful for improving the hydrostatic piezoelectric properties of type 1–3 piezoelectric composites.

Design, fabrication and testing of a high frequency broadband hydroacoustic transducer for sonar systems

A high frequency broadband hydroacoustic transducer was fabricated for applications such as small target detection and fine imaging in sonar systems. The utilization of the structure design of multimode coupling theory is employed to expand the operational bandwidth of the transducer by leveraging the characteristics of 1–3 type piezoelectric composites that possess a broad frequency range. Piezoelectric composite sensitive elements of varying thicknesses were developed through optimization of dimensional parameters using theoretical and finite element simulation analyses. These composite sensitive elements were then bonded to a spiral stepped backing to enable lateral stacking, ultimately resulting in the fabrication of a high frequency broadband hydroacoustic transducer. The outcomes of the underwater performance evaluation indicate that the transducer's central frequency is 310 kHz, with a −3 dB bandwidth capable of reaching 100 kHz. The maximum transmit voltage response is 159 dB, while the maximum receive sensitivity is −182 dB. Additionally, the directional beam opening angle of −3 dB at the center frequency is roughly 9°, which effectively broadens the transducer's bandwidth.

3D printed 0–3 type piezoelectric composites with high voltage sensitivity

Piezoelectric composites made of piezoelectric ceramic particles and polymer composites combine the performance advantages of both components and have broad application prospects. However, the preparation of complex structures is still a challenge, for which 3D printing technology provides a perfect solution. The aim of the present study is to investigate the principle and process optimization of the stereolithography of 0–3 type piezoelectric composites through simulation and experiments. In particular, a modified three-phase model of a spherical shell is applied to elucidate the influence of the elastic modulus between the ceramic particles and the matrix on the piezoelectric properties of the composites at the macroscopic level. This enables the piezoelectric properties of the composites to be predicted more accurately, and guides the surface grafting modification of piezoelectric ceramic powders. Furthermore, the problem of weak interface bonding in piezoelectric composites caused by poor compatibility between hydrophilic particles and the hydrophobic matrix is successfully solved by preprocessing the PZT ceramic powder via activating the particle surface hydroxyl groups and grafting a silane coupling agent onto the piezoelectric ceramic powder. As a result, the particles are bonded to the matrix by covalent bonds, which increases the elastic modulus of the interface transition layer and modifies the stress transfer efficiency. For instance, the piezoelectric strain constant (d33) of piezoelectric composite containing 60 wt% functionalized PZT particles is increased from 20 to 37 pC/N. The printing accuracy, piezoelectric properties, and mechanical characteristics of the piezoelectric composites are thoroughly investigated, and the reliability of the proposed theoretical model and simulation results is verified. The piezoelectric composites are uniformly compact and have a low residual pore rate. The piezoelectric composite with a solid content of 60 wt% has a volume density of 2.27 g/cm3 and a Young's modulus of 535.44 MPa. Most importantly, its piezoelectric voltage constant (g33) is 167.2 × 10−3 Vm/N, which is more than seven times higher than that of homogeneous PZT and results in high voltage sensitivity.

Flexible pillar-base structured piezocomposite with aligned porosity for piezoelectric energy harvesting

Flexible piezoelectric energy harvesters have attracted significant attention in recent years due to their ability to convert strain energy associated with bending into electrical energy for low-power wearable electronic devices. Compared with 0–3 type piezoelectric composites, where the piezoelectric phase is isolated within the material, flexible piezoelectric energy harvesters based on a three-dimensional interconnected ceramic skeleton are of particular interest due to their high stress transfer capability and high piezoelectric coefficients. Herein, a three-dimensional interconnected porous barium calcium zirconate titanate (BCZT) pillar-based structure is created via freeze casting, where polydimethylsiloxane (PDMS) is impregnated into the aligned pore channels to form a flexible piezoelectric energy harvester. The effect of porosity on piezoelectric coefficients, ferroelectric properties and energy harvesting performance is investigated in detail. The piezoelectric coefficient and energy harvesting figure of merit are significantly enhanced due to the presence of an aligned pore structure which leads to a high transfer of applied stress into the piezoelectric phase. The highly aligned porosity leads to the creation of a piezoelectric composite with 60 vol% of polymer that exhibits a high output voltage of 30.2 V and current of 13.8 μA. Moreover, the peak power density can reach up to 96.2 μW cm −2 , which is significantly higher than that of nanoparticle-based piezoelectric composites. This work demonstrates a promising prospect of utilizing flexible piezoelectric composites for energy harvesting applications. A flexible piezoelectric energy harvester based on BCZT pillar-base composite with aligned porosity is achieved via a freeze casting technique. Enhanced piezoelectric properties and energy harvesting performance ( V = 30.2 V, I = 13.8 μA at a porosity of 60 vol%) are realized due to the high poling efficiency and improved stress transfer, which is capable of charging capacitors and illuminating commercial LEDs. • Flexible pillar-base structured piezocomposite with highly aligned porosity is developed via freeze casting. • The piezoelectric energy harvesting performance is significantly enhanced due to the presence of an aligned pore structure. • Piezoelectric composite with 60 vol% of polymer exhibits a maximum power density of 96.2 μWcm −2 . • It is demonstrated to have the ability to charge capacitors and illuminate commercial LED bulbs.

Effective piezoelectric coefficients of cement-based 2–2 type piezoelectric composites based on a multiscale homogenization model

The effective piezoelectric properties of the cement-based 2–2 type piezoelectric composites have been investigated both experimentally and theoretically. The two-scale asymptotic expansion method is employed to develop a homogenized model for the effective properties calculation. The validity of the theoretical solution is confirmed through the comparison with the experimental results. The influence of the volume fraction of the piezoelectric phase on the effective piezoelectric coefficients is then examined. It is found that higher volume fraction will induce obvious increment of the magnitude of the effective piezoelectric strain coefficients d31Eff, d32Eff, and d33Eff, however, the hydrostatic piezoelectric strain coefficient dhEff will reach a maximum value at a lower volume fraction.

Performance comparison of 2-1-3, 1-3 and 1-3-2 piezoelectric composite transducers by finite element method

1-3 type, 1-3-2 type and 2-1-3 type piezoelectric composites are three proper smart materials for the design and manufacture of ultrasonic transducers. They have been proposed in different stages but possess similar properties. Compared with the initial 1-3 type composite, 1-3-2 composite is of higher mechanical stability. Compared with 1-3-2 composite, 2-1-3 composite has lower manufacturing difficulty. In this paper, a comparative study on these three composites in terms of receiving transducer material properties is presented. Finite element method (FEM) has been adopted to calculate longitudinal velocity, thickness electromechanical coupling coefficient and voltage receiving sensitivity. It is concluded that for a large aspect ratio $\alpha=1$, the performance of 2-1-3 composite transducer is much better than that of 1-3 and 1-3-2 composite transducers. The thickness electromechanical coupling coefficient of 2-1-3 composite transducer is about 5.58 times that of 1-3 composite transducer and 7.42 times that of 1-3-2 composite transducer. The voltage receiving sensitivity at 2 kHz of 2-1-3 composite transducer is 13.1 dB higher than that of 1-3-2 composite transducer and 12.3 dB higher than that of 1-3 composite transducer.

On the micro-mechanical study of 1–3 type piezoelectric composites with semi-coupled thermo-electro-elastic effects

This paper deals with a two-dimensional generalized plane strain micro-mechanical model to simulate semi-coupled thermo-electro-elastic behavior of transversely polarized piezoelectric fibrous composites. The solution domain includes a representative volume element (RVE) consists of a long piezoelectric fiber surrounded by corresponding matrix in a square array arrangement. Fibers have orthotropic and/or transversely isotropic properties while are perfectly bonded to the isotropic matrix. In addition, the constituents are assumed to have linear thermo-electro-elastic behavior. The virtual form of equilibrium equations has been extended to cover the semi-coupled thermo-electro-elastic loading by using appropriate constitutive relations. The element-free Galerkin method is employed to discretize the governing equations in terms of three main primary variables including, displacements, electric potential and temperature. The performance of the present micro-mechanical study reveals close agreement compared with other techniques available in the literature. Based on the present study, ample results are addressed to provide an insight into the effects of the local fields, i.e. displacement, electric potential, electric field, and stress distributions within the RVE for the specific fiber volume fraction.

Performance Simulation and Fabrication of PZT Piezoelectric Composite Ring

High-frequency wideband omnidirectional transducer is the development direction of the research of underwater acoustic transducer, PZT piezoelectric composite ring is not only capable of horizontal omnidirectional transmitting and receiving underwater acoustic signal. Meanwhile, it also makes the bandwidth of the transducer is expanded. Using the ANASYS finite element simulation software, the modal simulation of the ring structure of the 2-2 type piezoelectric composite is carried out, and the relationship curve of the bandwidth and the structure size is obtained. Based on the simulation, a design scheme is formed, cutting circular piezoelectric ceramics along the axial direction, there is epoxy resin in the groove. Thus the 2-2 type piezoelectric composite circular tube is formatted. The piezoelectric composite circular tubes suitable for horizontal omnidirectional broadband transducer.

Influence of cement matrix on properties of 1–3–2 connectivity cement-based piezoelectric composite

In order to develop cement-based piezoelectric intelligent composites suitable for concrete structural health monitoring, 1–3–2 type piezoelectric composites were fabricated by using piezoelectric ceramic as the functional component and epoxy resin and different kinds of cement as the matrix. The properties of the composites were studied. The results show that, compared with pure piezoelectric ceramic, the relative dielectric factor ε33of the composite decreased while the dielectric loss tan δ33increased. The planar electromechanical coupling coefficient Kp, mechanical quality factor Qmand acoustic impedance Z of all the composites decreased, while the thickness electromechanical coupling coefficient Ktincreased. The composite with ordinary Portland cement matrix had the largest values of ε33, tan δ33, Ktand d33(piezoelectric strain factor).

Finite Element Analysis of 1-3-2 Piezoelectric Composite Resonance Frequency Characteristics

Taking the finite element method, the resonant frequency of the 1-3-2 type piezoelectric composites is calculated by finite element analysis software ANSYS. The relationship between the thickness of the composite material and its resonant frequency of admittance characteristics are calculated. The different structural parameters 1-3-2 type piezoelectric composite material samples are designed and prepared. The results show that the theoretical calculations are well matched with experimental results .

Study on Novel Relaxor Ferroelectric Single Crystal PMNT/Epoxy Composite

Use relaxor ferroelectric single crystals PMNT as piezoelectric phase, epoxy resin as a non-piezoelectric phase material, take the cutting - filling method fabricated piezoelectric composite. Its structure character is achieved 1-3 type piezoelectric composites and piezoelectric crystal substrate composite again inseries by the integration, the composite horizontal and vertical bracket to be supported by piezoelectric crystal frame, it has a good impact resistance and affected by changes in ambient temperature characteristics. This composite material both has the advantages of 1-3 type composites, and has stable mechanical and thermal properties. Based on R.E.Newnhams series-parallel theory, combined with the structural characteristics of this composite, given the formula of piezoelectric composites density, piezoelectric constant, and dielectric constant. Fabricated the PMNT / epoxy composites and piezoelectric PZT / epoxy piezoelectric composite materials samples, which have the same scale, the same structural parameters. The experimental results show that, the piezoelectric composite test parameter values match theoretical calculations. The PMNT/epoxy composite has batter function than PZT/epoxy composite.

Theoretical analysis of underwater sound absorption of 0-3 type piezoelectric composite coatings

Recently piezoelectric shunt damping has attracted a lot of attention in vibration and noise control. In this article, piezoelectric shunt damping is used in underwater sound absorption in order to enhance the sound absorption of the coating. A one-dimensional electro-acoustic model is established for the calculation by combining the equivalent circuit of thickness mode of a piezoelectric composite coating with the transfer matrix of plane wave propagation. This model can be used to calculate the sound absorption of multiple layers of piezoelectric and non-piezoelectric mediums. Underwater sound absorption of the 0-3 type piezoelectric composite coatings is theoretically analyzed. Elastic, piezoelectric and dielectric constants of the 0-3 type piezoelectric composites are calculated by Furukawa's model. Results show that the negative capacitance circuit can adjust the surface acoustic impedance of the piezoelectric composite coating at broadband frequencies. Suitable shunt resistances can make it match the characteristic acoustic impedance of water better. Therefore, the sound absorption can be greatly promoted.

Fabrication and properties of piezoelectric composites designed for process monitoring of cement hydration reaction

A series of receiving type piezoelectric composites were designed and fabricated by cutting and filling technique. The piezoelectric composites were also optimized from such aspects as matrix phase, functional phase and composite connectivity. The researches show that these piezoelectric composites have larger piezoelectric voltage factor, thickness electromechanical coupling coefficient and lower acoustic impedance than the pure piezoelectric ceramic. The early cement hydration reaction process monitoring result indicates that the ultrasonic wave receiving ability of the piezoelectric composite is obviously better than that of the pure piezoelectric ceramic. Therefore, these kinds of piezoelectric composites have potential application prospect in cement hydration reaction process monitoring.

Fabrication and Properties of 1-3 Polymer Modified Cement Based Piezoelectric Composites

A piezoelectric ceramic(lead niobium lithium zirconate titanate, P(LN)ZT), sulphoaluminate cement and polymer were used to fabricate polymer modified cement based piezoelectric composites by cut-filling technique. The influence of P(LN)ZT volume fraction on the electromechanical properties and acoustic impedance of composite was investigated. Comparing with P(LN)ZT Piezoelectric ceramic, the vibration at thickness mode of 1-3 type piezoelectric composite is strengthened, and the electromechanical quality factor is reduced. When P(LN)ZT volume fraction is 30.86%, the acoustic impedance value is 8.24 M rayl, which is close to that of the concrete (9.0 M rayl), and this is suitable for the non destructive inspection.

Dependence of Aspect Ratio on1-3 Polymer/Cement Based Piezoelectric Composite Properties

Piezoelectric ceramic(lead niobium lithium zirconate titanate, P(LN)ZT), sulphoaluminate cement and polymer were used to fabricate 1-3 polymer/cement based piezoelectric composites by cut-filling technique. The influence of P(LN)ZT aspect ratio on the piezoelectric and dielectric properties of composites was investigated. The results show that as the P(LN)ZT aspect ratio increases, the piezoelectric strain factor d33 and relative dielectric factor εr decrease evidently, while the piezoelectric voltage factor g33 decreases slowly. The acoustic impedance Z is hardly influenced by the aspect ratio. At the same time, the influence of temperature on the dielectric properties of the composites was studied. The results show that with increasing the temperature at the frequency of 1kHz and 150 kHz, the dielectric factor εr exhibits the trend of increase. In the range of -40°C-110°C, the dielectric loss tanδ first increases slowly, but when exceeding the temperature of 80°C, it increases evidently. Comparing with P(LN)ZT piezoelectric ceramic, the vibration at thickness mode of 1-3 type piezoelectric composite is strengthened.

Piezoelectric and dielectric behavior of 0-3 cement-based composites mixed with carbon black

Cement-based 0-3 type piezoelectric composites, fabricated from white cement, lead zirconate titanate (PZT) powder and small amounts of carbon black, are exploited for potential applications in civil engineering. The nature of the aging and poling behavior of the carbon black/PZT/cement composites is investigated. It is shown that the use of a conductive carbon black phase can facilitate the poling process at room temperature. The influences of the carbon black on the piezoelectric and dielectric properties are studied as well. It is demonstrated that the piezoelectric sensitivities of the composites can be dramatically enhanced by incorporation of small amounts of carbon black, due to its conductive properties. With a poling field of 4 kV/mm and poling time of 20 min, the d 33, ɛ r , tan δ and K t values of the composite containing 70 vol.% PZT and 1.0 vol.% carbon black are 28.5 pC/N, 202.6, 0.19 and 12.2%, respectively.

FABRICATION AND ELECTRICAL PROPERTIES OF PZT-PVDF 0–3 TYPE COMPOSITE FILM

ABSTRACT A film speaker was fabricated with 0–3 type piezoelectric composite. The 0–3 type composite was developed to incorporate the advantages of both ceramic and polymer. The pastes of PZT-PVDF composite were made with various mixing ratio. The paste was printed by conventional screen-printing method on ITO (Indium Tin Oxide) bottom electrode which was deposited on PET (polyethylene terephthalate) polymer film. The prepared composite film was about 80 μm in thickness. After printing the top-electrode of silver-paste, 4 kV/mm of DC field was applied at 120°C for an hour to align the electric dipole in the 0–3 composite film. The piezoelectric charge constant of d33 was increased with increasing the PZT weight percent. The maximum value was 24 pC/N at 70 wt% of PZT. But the piezoelectric voltage constant of g33 had the maximum value about 32 mV · m/N at 65 wt% of PZT. The SPL (Sound Pressure Level) of the speaker fabricated with the 65:35 composite film was tested at various driving voltages of 1 ∼ 100Vrms. The SPL was saturated at the driving voltage of 70Vrms and the value was about 68 dB at 1 kHz.

A study of a 1-3-2 type piezoelectric composite

A novel 1-3-2 type piezoelectric composite is developed. There are piezoelectric ceramic framework supports at transverse and longitudinal directions in its structure, so it is free from the influence of any outside mechanic impact and environmental temperature change. The sample characteristic is good coherence. It has many advantages, such as a high piezoelectricity, lower density and acoustic impedance matching with water and tissue easily. Based on Newnham’s series and parallel theory of composites, the calculation formulae of dielectric and piezoelectric constants of a 1-3-2 type piezoelectric composite are deduced. The sample’s characteristics indicate that a 1-3-2 type piezoelectric composite’s theoretic calculation values are in good agreement with the measurement results. Element samples have been designed, manufactured and measured. The results indicate that the resonant frequency, resonant impedance, piezoelectricity and static capacity of these samples are stable. It is easy to design sensor array elements using this material.

Calculations of the effective properties of 1-3 type piezoelectriccomposites with various rod/fibre orientations

The effective properties of non-conventional 1-3 type piezoelectriccomposites with various orientations of lead zirconate titanate rods/fibresaligned in an epoxy matrix are calculated using the recently developed Green's functiontechnique. The effects of the volume fraction and(polarization) orientation of the ceramic rods/fibres on the effectivepiezoelectric properties are presented in detail. The theoreticalpredictions demonstrate the interesting behaviour of the composites andprovide a general guideline for optimizing the microstructural scale of suchnon-conventional 1-3 composites for piezoelectric transducers.