Piezoelectric Ceramic Vibrator Research Articles

Elucidation of the “jumping and dropping” phenomena of piezoelectric vibrators in high-amplitude operation in the vicinity of their mechanical resonance frequencies

Abstract The peculiar events called the “jumping and dropping” phenomena of piezoelectric ceramic vibrators in high amplitude operation have widely been known. The phenomena, which occur solely in the vicinity of the mechanical resonance frequencies of the vibrators, are the emergence of hysteresis in frequency domain with abrupt increase and decrease of the vibratory amplitude. It has long been believed that the nonlinearity of the piezoelectric materials is the dominant cause of the unstable vibratory behaviors. Nevertheless, the authors have found that they can be attributed to the local piezoelectric polarization reversals due to the electric field concentration caused by its conspicuous distortion inside the vibrators in mechanical resonance. This hypothesis has been examined by numerical and experimental investigations for hard-type piezoelectric ceramic disks vibrating in axisymmetric radially pulsating mode.

Acoustic and rheological characterization of hollow glass microsphere composite for development of optimized air-coupled ultrasonic matching layer

An air-coupled acoustic matching layer, based on hollow glass microsphere composite, was developed for air-coupled ultrasonic transducers. The effects of the matrix, powder series, and volume fraction were systematically analyzed by acoustic and rheological characterization. The optimized hollow glass microsphere-epoxy composite showed a superior air-coupling performance, with a characteristics acoustic impedance of 1.08 MRayl and attenuation coefficient of 0.05 dB/mm, respectively. To validate the developed composite, an air-coupled ultrasonic transducer was fabricated with piezoelectric ceramic vibrator, and its feasibility for application in a gas flowmeter was demonstrated. The developed composite exhibits a suitable air-coupling performance for a high-accuracy ultrasonic gas flowmeter.

Piezoelectric Composite Vibrator with a Bilaminated Structure for Bending Vibration

A piezoelectric composite vibrator with a bilaminated structure is designed and fabricated, in this work by applying bending vibration to increase vibration displacement and reduce resonance frequency. The finite element software ANSYS (ANSYS, Inc. USA) is used to simulate the 2-2 and 1-3 piezoelectric composite bilaminated vibrators under free boundary condition and optimize their design. Simulation results show that the vibration displacement of the 2-2 vibrator is higher than that of the 1-3 vibrator, and the resonance frequency of the former is lower than the latter. Five pieces each of the 2-2 and piezoelectric ceramic vibrators are prepared. In addition, simulation and experimental results indicate that the vibration displacement of the 2-2 vibrator increases by 2.3 times, whereas its resonance frequency decreases by nearly 100 Hz, in comparison with those of the piezoelectric ceramic bilaminated vibrator.

A Method for Reducing the Drag of the Ship Shaped Wall by Using Piezoelectric Ceramic Vibrators

High-frequency and micro-amplitude vibration applied on ship walls in the fluid can interfere with the coherent structure of the boundary layer near the wall to achieve drag reduction. This paper presents a method to reduce the drag of the ship-shaped wall by using piezoelectric ceramic vibrators. Piezoelectric ceramics are glued on the inside wall to excite wall vibration which is perpendicular to the flow direction. The drag reduction characteristics of a ship-like body model were studied. The influences of vibration amplitude of piezoelectric vibrator, vertex angle, and moving velocity on the drag reduction characteristics were analyzed by finite element simulations. The maximum drag reduction rate is up to 48.96% in the case of the vertex angle of 10° and the vibration amplitude of $6~\mu \text{m}$ . A prototype and the corresponding experimental platform were designed and manufactured. Experiments were carried out, and the comparison of the experimental results and the simulation results verifies that the proposed drag reduction method is feasible and effective. This paper provides an effective way to reduce the resistance of ship navigation.

Self-adaptive piezoelectric ceramic vibration system based on asymmetric piezoelectric cantilever for energy harvesting

Micropower energy harvesting is one of key technologies for the micromation and practical development of wireless sensor and communication node networks. A self-adaptive piezoelectric vibration system based on modified homogeneous strain asymmetric PZT piezoelectric ceramic cantilever beam for the micropower energy harvesting was designed and prepared. A vertical cantilever was designed at the first time to obtain the homogeneous state of stress which can largely increase the power output and energy harvesting efficiency of piezoelectric cantilevers. In order to achieve the self-adaptive vibration, the asymmetric structure was adopted. Asymmetric cantilevers moved horizontally and changed the length of main cantilevers when affected by the variation in external frequency excitation, thus, the switching of resonant frequency was archived automatically without dissipating additional energy.

Domain structure of nonstoichiometric sodium potassium niobate-based ceramics for piezoelectric acoustic actuators

In this work, three piezoelectric acoustic actuators are prepared by using multi-layer technology for lead-free (Na0.48-xK0.48-xLi0.04)Nb0.89-xTa0.05Sb0.06O3-xSrTiO3 (NKLNTS-xST) ceramics, x=0 and 0.007, and commercial lead-based ceramic. The phase and domain structure are also investigated by using the XRD patterns and TEM images of the NKLNTS-xST ceramics. The (Na0.473K0.473Li0.04Sr0.007)Nb0.883Ti0.007Ta0.05Sb0.06O3 piezoelectric acoustic actuator has the best sound pressure level and d33 value of 650pCN−1. The response mechanisms suggest that the piezoelectric ceramic vibration amplitude was increased and the sound pressure level improved since the orthorhombic and tetragonal phases were found to coexist and the nanoscale domain increased for the (Na0.473K0.473Li0.04Sr0.007)Nb0.883Ti0.007Ta0.05Sb0.06O3 ceramic.

Research on Electronic Materials with Design on the Narrow-Band FIR Filter Based on Multiple Sampling Frequency

This paper introduces the basic structure of narrow-band FIR filter and conducts detailed analysis on the various components of narrow-band FIR filter. Based on the CIC and HBF, this paper further designs narrow-band FIR filter with the sampling rate of 100 KHz. The materials of filter adopt the piezoelectric ceramic vibrator with high mechanical quality factorand high stability .Moreover, the simulation results indicate that this filter can greatly reduce the calculation amount and storage capacity so as to satisfy the real-time processing requirements of the signals.

Electric Polarization Characteristic and Equivalent Circuit of the Pb(Zr<sub>0.95</sub>Ti<sub>0.05</sub>)O<sub>3</sub> Nanoceramics

In this paper, the PZT nano-ceramics were prepared by an improved Sol-Gel method. This method was based on recording to A.S.Mischenko. TF Analyzer 2000 FE was used to measure the ferroelectric properties of the samples. The results show the change trends of the P-E hysteresis loops in different voltages, temperatures and frequencies. Impedance was tested by precision impedance analyzers 6500 series. With the use of the equivalent circuit to simulate the piezoelectric ceramic vibrator we can get a conclusion that in the 85 MHz-120 MHz the response of the sample can be represented with a RLC series resonant circuit. The resonant frequency of the sample is 97.12MHz, and the loss is very low. Compared with the general piezoelectric vibrator PZT 95/05 nano-ceramic is a low frequency capacitor with the capacitance tend to 0 F.

우주환경하의 위성부품용 압전진동자 활용에 관한 연구

위성체가 작동하는 우주환경인 초고진공상태에서는 각 부품에서 발생 할 수 있는 기체방출로 인해 위성체가 오염되어 위성체의 성능이 저하될 수 있으며, 특히 광학렌즈를 오염시킴으로써 위성체 본연의 임무수행 실패라는 결과를 초래할 수도 있다. 최근 항공우주분야에서 활용 범위가 넓어지고 있는 PZT-5 계열 압전진동자의 위성부품 활용성 연구를 위하여 먼저 Collected Volatile Condensable Material 및 Total Mass Loss을 측정하여 규정된 0.1% 및 1.0% 이하의 값을 얻었고, 한국항공우주연구원에 설치된 베이크아웃(bake-out) 챔버를 이용하여 고온 및 고진공상태에서 500 <TEX>$ng/cm^2/hr$</TEX> 이하의 낮은 Thermoelectric Quartz Crystal Microbalance 값을 얻어 위성체 부품으로의 적합성을 재확인하였다. 압전진동자에 대한 고진공 환경 전후의 압전 특성을 비교 분석한 결과 진공환경에 의한 전기-기계적 특성은 1% 미만으로 큰 변화가 없음을 확인하였다. In the high vacuum condition of the space, outgassing from any assembly of satellite can contaminate satellites, especially second surface mirror and optical lens, it cause satellite to fail in own missions. Therefore, all unit shall be check for compatibility with vacuum using CVCM (Collected Volatile Condensable Material) and TML (Total Mass Loss) in advance. CVCM and TML of the PZT-5 piezoelectric ceramic vibrator has less than 0.1% and 1.0% respectively. Also, it has less than 500 <TEX>$ng/cm^2/hr$</TEX> of Thermoelectric Quartz Crystal Microbalance for vacuum bake-out test using high temperature(more than <TEX>$80^{\circ}C$</TEX>) and high vacuum (less than <TEX>$5.0{\times}10^{-3}$</TEX> Pa). Thus, piezoelectric ceramic vibrator may be employed in the vacuum environments. Finally, it can be confirmed that the characteristics change of the piezoelectric ceramic vibrator is less than 1% under vacuum environments.

우주환경하에서 횡진동 모드 PZT진동자의 특성변화 예측

The temperature dependence of the characteristics in a PZT-5 piezoelectric ceramic vibrator with the transverse mode was investigated in the range of to using a thermal vacuum chamber to utilize the vibrator in aerospace industries. As the results, at room temperature, the resonant and anti-resonant frequencies had the minimum value, whereas, the dielectric constant increased linearly from about 2500 to 7500 in the given temperature range. The mechanical loss decreased linearly from 0.08 to 0.03. Through the regression analysis, the temperature dependence functions of the characteristics were derived to linear and square regression functions. Applying the functions, the input admittance characteristics of the piezoelectric vibrator were calculated, and the results showed good agreement with measured ones. It can be confirmed that this method is useful to estimate the characteristics change of the piezoelectric vibrator caused by the temperature change under the space environment.

Research on Properties of PZT Piezoelectric Ceramics by Finite Element Softeware ADINA

In this paper, the finite element model of piezoelectric ceramics in line with the experiment results was established according to piezoelectric structure field and the coupling of the electric field, deformation of representative PZT piezoelectric ceramics under the voltage was analysed in using finite element analysis software ADINA according to establishing geometric model, defining boundary conditions and materials, Coupling calculation. Consistency between simulation results and experimental results is improved and lay the foundation for the realization of the piezoelectric ceramic shapes and vibration control.

Analysis of PZT Piezoelectric Ceramics Based on Finite Element Softeware ADINA

Using traditional experiment means on piezoelectric ceramic device has certain limitations due to the complicated boundary conditions and stress situation. In this paper, the finite element model of piezoelectric ceramics in line with the experiment results was established according to piezoelectric structure field and the coupling of the electric field, deformation of representative PZT piezoelectric ceramics under the voltage was analysed in using finite element analysis software ADINA according to establishing geometric model, defining boundary conditions and materials, Coupling calculation. Consistency between simulation results and experimental results is improved and lay the foundation for the realization of the piezoelectric ceramic shapes and vibration control.

Development of Ultrasound Exposure System of Four Piezoelectric Ceramic Vibrators with Operating Frequency of 150 kHz for Dispersion of Nanometer-Sized Diamond Particles

A novel ultrasound exposure system for the dispersion of nanometer-sized diamond particles was developed. The nanometer-sized diamond particles have a primary particle size of about 5 nm and are expected to be used as an abrasive agent in the future. However, the diamond particles are aggregated to a size of about 5 µm immediately after manufacture, and a hard disk surface is scratched by such aggregated diamond particles. It is important that the diamond particles are uniformly dispersed in water. Therefore, the dispersion of the diamond particles using an ultrasound exposure system with four lead titanium zirconate (PZT) piezoelectric ceramic vibrators and an acoustic matching layer was investigated. As a result, the diamond particles were dispersed to a particle size of about 75 nm by acoustic cavitation due to ultrasound exposure.

1-07P-51 Development of Ultrasound Exposure System of Four Piezoelectric Ceramic Vibrators with Operating Frequency of 150 kHz for Dispersion of Nanometer Sized Diamond Particles(Poster session 1)

1-07P-51 Development of Ultrasound Exposure System of Four Piezoelectric Ceramic Vibrators with Operating Frequency of 150 kHz for Dispersion of Nanometer Sized Diamond Particles(Poster session 1)

Basic study on one-dimensional transducer array using hydrothermally synthesized lead zirconium titanete poly-crystalline film

Recently, high-frequency miniature medical ultrasound probes with high resolution were actively developed. However, it is difficult to fabricate such tiny ultrasound probes using piezoelectric ceramic vibrator with thickness less than 100 μm. We deposited a PZT poly-crystalline film on a titanium substrate using the hydrothermal method and developed transducers using the PZT poly-crystalline film for ultrasound probes. In this study, we applied it to a miniature medical one-dimensional (1-D)-array-type ultrasound probe with resonance frequency of 10 MHz. After sputtering of pure titanium on the surface of a hydroxyapatite substrate, the titanium film was etched using the photolithography method to form a 1-D titanium film electrode array with 75 μm element pitch, 40 μm element width, and 4 mm element length to scan an ultrasound beam electronically by sector scan mode using phased-array technique. Thereby we fabricated a miniature 1-D-array-type ultrasound probe. A transmitted ultrasound pulse from 10 MHz commercial ultrasound probe was received by this fabricated 1-D-array type ultrasound probe with hydrothermally synthesized PZT poly-crystalline film vibrators.

Vibration-Stress Dependence of Electromechanical Characteristics for Electrostrictive Pb(Mg1/3Nb2/3)O3–Based Ceramics

The mechanical quality factor Qm of a normal ferroelectric, piezoelectric ceramic vibrator decreases and heat is given off, when the vibrator is continuously driven at a high level of vibration-stress under a resonant mode. It has been thought that irreversible motions of ferroelectric non-180° domain walls cause this behavior. The effect of ferroelectric domain structure on the vibration-stress dependence of electromechanical characteristics was studied using relaxor ferroelectric electrostrictive (1-x)PbTiO3-xPb(Mg1/3Nb2/3)O3 (x=1.00, 0.95, 0.90) ceramics. The Qm for the paraelectric crystal phase composition at room temperature is about five times higher than that for hard lead zirconate titanate (PZT) and the decrease of Qm with vibration-stress is suppressed at high stress levels. The piezoelectric d31 constant is almost the same as that of hard PZT. Electrostrictive ceramics are therefore superior electromechanical vibrator materials for high power applications.

Current Oscillation of Piezoelectric–Ceramic Vibrators Driven by a Constant High Electric Field

Current oscillation will occur when a piezoelectric ceramic vibrator is driven by a high electric field. The mechanism of current oscillation is discussed, based on the results of the present experiment. Ring‐shaped lead zirconate titanate (PZT) piezoelectric vibrators are driven by a 5.65 V electric field with a fixed frequency of slightly less than resonance, to form an oscillating current. The sample current, temperature, and phase between the driven electric field and sample current are recorded. The resonance frequency of PZT rings shifts in the direction of low frequency under a high electric field due to the heat produced by dissipated power, and then shifts back due to the effects of aging, which results in current oscillation. The oscillation phenomenon is explained according to the production of strong internal stresses due to abrupt change in temperature, and then, aging process through the rearrangement of domains to relieve various stresses.

Characteristics of the First Longitudinal-Fourth Bending Mode Linear Ultrasonic Motors

Linear ultrasonic motors using a combination of the first longitudinal mode and the fourth bending mode were designed and fabricated. The driving characteristics of the motors, which were composed of a straight metal bar bonded with piezoelectric ceramic vibrators as a driving element, were measured. Unimorph and bimorph ceramic vibrators were attached on three kinds of metal bars for constructing the stators of the linear motors. As results, motors made with the bimorph ceramic vibrators had higher velocity than motors of the unimorph vibrators. As a metal bar for stator, magnesium alloy, which has lower elastic coefficient than aluminum alloy, was better for the motors.

Piezoelectric Ceramic Vibration Modes and Potential Applications

Piezoelectric Ceramic Vibration Modes and Potential Applications

Detection of harmonic ultrasound scattered from microbubbles with ultrasound transducer for harmonic imaging having double peak type frequency characteristics

Ultrasound transducer with double peak type frequency characteristics was proposed for contrast harmonic imaging. It can transmit ultrasound in a fundamental mode and receive the second harmonic signal from tissues or microbubble contrast agents. The transducer has been made by stacking a piezoelectric ceramic vibrator and a subvibrating plate on the backing block made of ferrite rubber with an acoustic absorption. Glass subvibrating plate (0.4 mm thick) was found suitable for this ultrasound transducer. The second harmonic component contained in the scattered waves from microbubbles coated with surfactant was detected experimentally with a trial manufactured ultrasound transducer with double peak type frequency characteristics. The results confirmed that the transducer can transmit ultrasound to microbubbles, excite the second harmonic component based on the nonlinear behavior of microbubbles and detect the second harmonic component. It was also found that the second harmonic component can be detected most effectively when burst waves with cycles from 5 to 10 were applied to the ultrasound transducer.