• Title/Summary/Keyword: piezoelectric transducer

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Power Generation Characteristics of Uni-morph Piezoelectric Cantilever with Different Vibration Angle (진동 각도에 따른 유니몰프 압전 캔틸레버의 발전특성연구)

  • Kim, Chang Il;Yun, Ji Sun;Park, Woon-Ik;Jeong, Young-Hun;Hong, Youn Woo;Cho, Jeong-Ho;Paik, Jong Hoo
    • Journal of Sensor Science and Technology
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    • v.26 no.2
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    • pp.107-113
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    • 2017
  • Energy source of a piezo-electric harvester is vibration. Sources of vibration are machineries operated with high frequencies, constructions and people operated with low frequencies and etc. In this study, we tried to figure out power generation properties over vibrations upon angles of a piezo-cantilever for applying them to movements of the construction and/or people, which are vibration sources at low frequencies. A uni-morph cantilever with a $59mm{\times}29mm{\times}0.2mm$ piezo-electric element attached on a $71mm{\times}46mm{\times}0.25mm$ copperplate was used. A spring was attached to the lower side of the cantilever and a mass was attached on the opposite side. Also, a structure with a specific angle which is an angle in between the ground and the cantilever was prepared and then, connected to a spring or the cantilever. Then, this structure was divided into the A-type and B-type and excited in the direction of z- axis. After that, the angle between the ground and the cantilever was changed and excited by 1 to 10 Hz upon the existence of a spring and/or a mass to compare power generation properties.

Piezoelectric immunosensor for the detection of Edwardsiellosis

  • Hong, Sung-Rok;Choi, Suk-Jung;Jeong, Hyun-Do;Hong, Su-Hee
    • Journal of fish pathology
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    • v.20 no.3
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    • pp.307-313
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    • 2007
  • In this study, a QCM biosensor was made to detect Edwardsiella tarda (E. tarda) using a specific antibody. A 9 MHz AT-cut piezoelectric wafer layered with two gold electrodes of 5mm diameter had a reproducibility of 0.1 Hz in frequency response and was used as the transducer of the QCM biosensor. Self assembled layer (SAM) was conformed on a quartz crystal by treating with 3-mer-captopropionic acid (MPA) and activated with N-ethyl-N'-(3-dimethyl-aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The resulting NHS group was further converted to hydrazide by the reaction with hydrazine. Aldehyde group was introduced into the carbohydrate moiety of anti-E. tarda antibody by the reaction with periodic acid and was used to immobilise the antibody through the reaction with hydrazide group on the electrode surface. A baseline was established in the presence of phosphate-buffered saline (PBS) and a resonant frequency (F1) was measured. Sample was added to the sensor surface and second resonant frequency (F2) was measured after unbound substances were washed out with PBS several times. Finally, the frequency shift (ΔF) representing the mass change was calculated by subtracting F2 from F1. After adding the oxidized anti-E. tarda antibody to the electrode surface containing hydrazide group, frequency shift of 288.811.4 Hz (mean S.E) was observed, thus proving that considerable amount of antibody was immobilized. In the immunoassay test, the frequency shift of 1877.75 Hz, 580.67 Hz, 221.39 Hz, 7.671.83 Hz (mean S.E) were observed at doses of 1000, 500, 100, 50 g of bacterial cells, respectively. It was also demonstrated that the prepared sensor chip was stable enough to withstand repeated surface regeneration with 0.2 M Tris-glycine and 1 % DMSO, pH 2.3 more than ten times.

Improving Wave Propagation Performance of an Ultrasonic Waveguide for Heat Isolation (열 차단용 초음파 도파관의 전파성능 향상 연구)

  • 최인석;전한용;김인수;김진오
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.7
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    • pp.545-553
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    • 2003
  • This paper is concerned with protecting piezoelectric transducers used in an ultrasonic flowmeter from the high temperature of hot fluid in a pipe by using a waveguide and with improving the propagation of ultrasonic longitudinal vibration in the waveguide. Waveguide material has been chosen for efficient insulation of heat transferred in the waveguide, and the minimum length of the waveguide for protecting piezoelectric transducer has been estimated. Forced response of the longitudinal vibration in a uniform circular rod has been obtained and the length of the waveguide has been selected for maximum amplitude. Longitudinal vibration response of a conically-tapered rod excited at a natural frequency has been obtained to confirm that wave motion is amplified as the cross-sectional size of the waveguide decreases along the axial direction. The fact that dispersion of a pulse wave in a waveguide is reduced as the cross-sectional radius is decreased has been examined theoretically and confirmed experimentally by using a single-rod waveguide. A bundle-type waveguide has proven to be a practical one through the evaluation of the wave propagation performance.

Investigating the Spatial Focusing of Time Reversal Lamb Waves Using a Virtual Sensor Model on a Rectangular Plate (직사각형 판에서 가상탐지자 모델을 이용한 시간반전램파의 공간모임 규명)

  • Park, Hyun-Woo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.5
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    • pp.553-567
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    • 2011
  • During the last three years, the possibility of the time reversal Lamb waves has been paid attention to for structural health monitoring of a plate. This study proposes a numerical scheme which can simulate the spatial focusing of time reversal Lamb waves on a rectangular plate. In this scheme, a time reversal process is formulated in the frequency domain using active virtual sensors being equivalent to the mirror effects of an actual sensor due to wave reflection on the plate boundary. Forward and backward Lamb wave propagations are represented by scalar functions for simulating the spatial focusing of time reversal Lamb waves. The validity of the proposed scheme is demonstrated through the comparison to the results of finite element analysis in which the spatial focusing of time reversal Lamb waves is realized by wafer-type piezoelectric(PZT) transducers collocated on a rectangular plate.

Development and Characterization of Ultrasonic transducers for High Temperature Contact Measurement (고온 접촉식 탐상용 초음파 탐촉자 개발 및 평가)

  • Kim, Ki-Bok;Kim, Byoung-Geuk;Lee, Seung-Seok;Yoon, Nam-Won;Yoon, Dong-Jin;Ahn, Yoon-Kook
    • Journal of the Korean Society for Nondestructive Testing
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    • v.23 no.1
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    • pp.14-20
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    • 2003
  • Piezoelectric ultrasonic transducers for high temperature contact measurement were developed. These high temperature ultrasonic transducers (HTUT) consisted of bismuth titanate piezoceramic element whose Curie temperature is higher than $600^{\circ}C$, a backing material of the mixture of tungsten powder and inorganic binder, an inner alumina tube, a wear Plate and a housing. The operational frequencies or the HTUT were 1.04 and 2.08 MHz, respectively. Various commercially available couplants for high temperature were evaluated and compared. As a couplant for high temperature ultrasonic testing between HTUT and test specimen, gold epoxy was selected. The peak amplitude of pulse-echo signals from steel test specimen decreased with increasing temperature. The operational temperature of the HTUT reached up to $500^{\circ}C$ at which the continuous contact measurement was possible.

Fabrication of Two-Dimensional Array Hydrophones and Application to Ultrasonic Field Measurement (2차원 배열 수중청음기의 제작과 초음파 음장 측정에의 응용)

  • Ha, Kang-Lyeol;Kim, Moo-Joon;Kang, Gab-Joong;Hyun, Byung-Gook;Chae, Min-Ku;Imano, Gazuhiko
    • Journal of Sensor Science and Technology
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    • v.10 no.5
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    • pp.320-328
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    • 2001
  • Two-dimensional array hydrophones with $8{\times}8$ elements were designed and fabricated using the PVDF(Polyvinylidene fluoride) piezoelectric film, and the method and system for ultrasonic field measurement in several MHz $\sim$ tens of MHz band using the hydrophones was established. The characteristics of frequency response relating to the backing materials were analyzed with the Mason equivalent circuit for design, and the accuracy of ultrasonic field measurement relating to the sizes and kerfs of piezoelectric elements was discussed. Good results of the measurement of ultrasonic field formed by a circular plane transducer of 2.25MHz in water were obtained by the system with the array hydrophones.

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Dielectric and Piezoelectric Properties of $Pb(Sb_{1/2}Nb_{1/2})O_3-PbTiO_3-PbZrO_3$ Ceramics ($Pb(Sb_{1/2}Nb_{1/2})O_3-PbTiO_3-PbZrO_3$ 세라믹스에서의 유전 및 압전 특성)

  • Cha, Yoo-Jeong;Kim, Chang-Il;Jeong, Young-Hun;Lee, Young-Jin;Paik, Jong-Hoo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.310-310
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    • 2008
  • 본 연구에서는 (1-x) Pb(Zr0.515Ti0.485)$O_3$ - x Pb$(Sb_{1/2}Nb_{1/2})O_3$ + 0.5wt% $MnO_2$ 조성에 Pb$(Sb_{1/2}Nb_{1/2})O_3$ (PSN) (x=0.02, 0.04, 0.06, 0.08) 변화에 따른 미세구조 및 압전, 유전특성에 관해 고찰하였다. PSN 치환량이 증가함에 따라 정방정 (tetragonal)구조에서 삼방정(rhombohedral)구조로 상전이가 일어났으며, 결정립의 크기가 작아지는 것을 확인하였다. 전기기계결합계수 (kp) 는 PSN이 4 mol % 치환됨에 따라 증가하였으며, 더 이상 치환 시 감소하였다. PSN 치환에 따른 전기적 특성은, 결정구조, 결정립의 크기 및 2 차상 등의 미세구조와 긴밀한 관계가 있는 것으로 보여진다. 상경계(Morphotropic Phase Boundary) 영역인 0.96 Pb(Zr0.515Ti0.485)$O_3$ - 0.04 Pb$(Sb_{1/2}Nb_{1/2})O_3$ + 0.5wt% $MnO_2$ 조성에서 $\varepsilon{^T}_{33}/\varepsilon_o$ = 1109, $k_p$= 70.8 (%), $d_{33}$= 325 (pC/N)의 우수한 특성을 나타내었다.

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Acoustic Properties of Ultrasonic Transducer Using Piezocomposites (압전복합재료를 이용한 초음파 트랜스듀서의 음향 특성)

  • Lee, Sang-Wook;Ryu, Jeong-Tag;Nam, Hyo-Duk;Kim, Yeon-Bo
    • The Journal of the Acoustical Society of Korea
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    • v.26 no.2
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    • pp.80-86
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    • 2007
  • We have investigated on the development of 2-2 type piezocomposites that have better piezoelectric activity and lower acoustic impedance than those of conventional piezoceramics. In this study, we have investigated the piezoelectric and acoustic properties of 2-2 type piezocomposites sensor which was fabricated using dice-and-fill technique for the different volume fraction of PZT. The specific acoustic impedance of 2-2 type piezocomposites decreased linearly when PZT volume fraction was decreased. The resonance characteristics measured by an impedance analyzer(HP4194A) were similar to the analysis of finite element method (FEM). The resonance characteristics and the electromechanical coupling factor were the best when the volume fraction PZT was 0.6. It also showed the highest result from the standpoint of sensitivity, bandwidth and ring-down property and so on at the same condition. The specific characteristics show that the 2-2 type piezocomposites turned out to be superior to the ultrasonic sensor composed by single phase PZT.

A Study on the Attenuation of Surface Acoustic Waves by Optical Measurement Method (광학적 측정방법에 의한 표면 탄성파의 감쇠에 관한 연구)

  • You, I.H.;Kim, D.I.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.14 no.4
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    • pp.237-243
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    • 1995
  • We have studied methods of detecting attenuation of solid materials such as silicon wafer and piezoelectric $LiTaO_3$ by means of optical probing techniques. We have performed measurements of surface acoustic waves(SAW) generated from 90 degree wedge type transducer and also from inter-digital transducers(IDT). SAW of 20.0 MHz was generated on a silicon wafer from the 90 degree wedge type transducer and those of 20.8 and 14.5 MHz are generated on a $LiTaO_3$ from the IDT. Then any surface-corrugation resulted from the above SAW was investigated by He-Ne laser beams. We projected laser beams, which were modulated by an optical chopper, on the SAW of the same frequency and then measured the scattered beam by the lock-in amplifier. We modulated and synchronized both SAW and the incident laser beam as well as the phase sensitive detector(PSD) to the same frequency in order to simplify our measurement system. We obtained the attenuation coefficients of SAW to be $0.62{\sim}0.75dB/mm$(from IDT1, 20.8 MHz), and $0.60{\sim}0.72dB/mm$(from IDT2, 14.5 MHz), $0.83{\sim}1.28dB/mm$(from the wedge type), respectively.

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Experience with an On-board Weighing System Solution for Heavy Vehicles

  • Radoicic, Goran;Jovanovic, Miomir;Arsic, Miodrag
    • ETRI Journal
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    • v.38 no.4
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    • pp.787-797
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    • 2016
  • Mining, construction, and other special vehicles for heavy use are designed to work under high-performance and off-road working conditions. The driving and executive mechanisms of the support structures and superstructures of these vehicles frequently operate under high loads. Such high loads place the equipment under constant risk of an accident and can jeopardize the dynamic stability of the machinery. An experimental investigation was conducted on a refuse collection vehicle. The aim of this research was to determine the working conditions of a real vehicle: the kinematics of the waste container, that is, a hydraulic rotate drum for waste collection; the dynamics of the load manipulator (superstructure); the vibrations of the vehicle mass; and the strain (stress) of the elements responsible for the supporting structure. For an examination of the force (weight) on the rear axle of a heavy vehicle, caused by its own weight and additional load, a universal measurement system is proposed. As a result of this investigation, we propose an alternative system for continuous vehicle weighing during waste collection while in motion, that is, an on-board weighing system, and provide suggestions for measuring equipment designs.