• Title/Summary/Keyword: Piezoelectric Materials

Search Result 930, Processing Time 0.023 seconds

Development and Evaluation of Rack Type Piezoelectric Harvester for Smart Street Lamps Control (가로등 제어용 다층패드형 압전 하베스터의 개발 및 평가)

  • Kim, Chang-Il;Jeong, Young-Hun;Park, Woon Ik;Cho, Jeong-Ho;Jang, Yong-Ho;Choi, Beom-Jin;Park, Shin-Seo;Paik, Jong-Hoo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.29 no.11
    • /
    • pp.696-701
    • /
    • 2016
  • In this study, to increase output of road piezoelectric energy harvester, it was made into rack type in which many piezoelectric materials can be installed and load transfer device of the leverage type to transfer vehicle load was made. By paving it in the road, the output characteristics depending on vehicle load and speed were evaluated. Changing vehicle load, harvester output characteristics depending on speed changes were evaluated at the interval of 10 km/h from 10 km/h to 100 km/h. Also, by making a wireless switch and sending wireless signal with output of rack type harvester, whether to receive it was evaluated by distance. It was checked that all switches work up to front-to-back 100 m from harvester.

Figures of Merit of (K,Na,Li)(Nb,Ta)O3 Ceramics with Various Li Contents for a Piezoelectric Energy Harvester

  • Go, Su Hwan;Kim, Dae Su;Han, Seung Ho;Kang, Hyung-Won;Lee, Hyeung-Gyu;Cheon, Chae Il
    • Journal of the Korean Ceramic Society
    • /
    • v.54 no.6
    • /
    • pp.530-534
    • /
    • 2017
  • The figures of merit in the on-resonance and off-resonance conditions ($FOM_{on}$ and $FOM_{off}$) for the piezoelectric energy harvester (PEH) were measured and compared in $[(K_{0.485}Na_{0.515})_{1-X}Li_X](Nb_{0.99}Ta_{0.01})O_3$ (x = 0.04 ~ 0.09) (KNLNT) ceramics with various Li contents. The crystal structure of CuO-doped KNLNT ceramics changes from orthorhombic to tetragonal around the Li fraction of 0.065. The stable temperature range for the tetragonal phase widens to both higher and lower temperatures as Li is substituted. The piezoelectric charge constant ($d_{33}$), electromechanical coupling factor ($k_p$) and mechanical quality factor ($Q_m$) have maximum values at the Li fraction between 0.055 and 0.065 where the phase boundary lies between the orthorhombic and tetragonal phases. Both $FOM_{on}$ and $FOM_{off}$ have peak values around the phase boundary but the peak compositions are not exactly coincided. The optimal Li fraction in the KNLNT ceramic for a PEH application was found to be between 0.055 and 0.065.

Fabrication and Performance Evaluation of Flat-Type Multilayer Piezoelectric Ceramic Ultrasonic Transmitter (평판형 적층 세라믹 초음파 압전 트랜스미터의 제조와 성능 평가)

  • Na, Yong-hyeon;Lee, Min-seon;Cho, Jeong-ho;Paik, Jong-hoo;Lee, Jung Woo;Jeong, Young-hun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.32 no.3
    • /
    • pp.207-212
    • /
    • 2019
  • A flat-type piezoelectric ceramic ultrasonic transmitter was successfully fabricated for application in acoustic devices with cone-free diaphragms. The transmitter, possessing a center frequency of 40.6 kHz, exhibited a higher displacement characteristic for a multilayer type compared with a single layer type. Surface roughness treatment of an Al elastic diaphragm influenced a slight increase (1.1 dB) in the sound pressure level (SPL) at $10V_{rms}$ due to the enlarged surface area. The fabricated multilayer piezoelectric ceramic ultrasonic transmitter showed increasing SPL with increasing input voltage, with a maximum SPL of approximately 123.6 dB at $10V_{rms}$. This implies a doubly increased SPL density of $3.6dB/mm^3$, superior to that of a commercial open-type transmitter with a cone.

Optimal placement of piezoelectric curve beams in structural shape control

  • Wang, Jian;Zhao, Guozhong;Zhang, Hongwu
    • Smart Structures and Systems
    • /
    • v.5 no.3
    • /
    • pp.241-260
    • /
    • 2009
  • Shape control of flexible structures using piezoelectric materials has attracted much attention due to its wide applications in controllable systems such as space and aeronautical engineering. The major work in the field is to find a best control voltage or an optimal placement of the piezoelectric actuators in order to actuate the structure shape as close as possible to the desired one. The current research focus on the investigation of static shape control of intelligent shells using spatially distributed piezoelectric curve beam actuators. The finite element formulation of the piezoelectric model is briefly described. The piezoelectric curve beam element is then integrated into a collocated host shell element by using nodal displacement constraint equations. The linear least square method (LLSM) is employed to get the optimum voltage distributions in the control system so that the desired structure shape can be well matched. Furthermore, to find the optimal placement of the piezoelectric curve beam actuators, a genetic algorithm (GA) is introduced in the computation model as well as the consideration of the different objective functions. Numerical results are given to demonstrate the validity of the theoretical model and numerical algorithm developed.

Development of Stretchable PZT/PDMS Nanocomposite Film with CNT Electrode

  • Yun, Ji Sun;Jeong, Young Hun;Nam, Joong-Hee;Cho, Jeong-Ho;Paik, Jong-Hoo
    • Journal of Sensor Science and Technology
    • /
    • v.22 no.6
    • /
    • pp.400-403
    • /
    • 2013
  • The piezoelectric composite film of ferroelectric PZT ceramic ($PbZr_xTi_{1-x}O_3$) and polymer (PDMS, Polydimethylsiloxane) was prepared to improve the flexibility of piezoelectric material. The bar coating method was applied to fabricate flexible nanocomposite film with large surface area by low cost process. In the case of using metal electrode on the composite film, although there is no problem by bending process, the electrode is usually broken away from the film by stretching process. However, the well-attached, flexible CNT electrode on PZT/PDMS film improved flexibility, especially stretchability. PZT particles was usually settled down into polymer matrix due to gravity of the weighty particle, so to improve the dispersion of PZT powder in polymer matrix, small amount of additives (CNT powder, Carbon nanotube powder) was physically mixed with the matrix. By stretching the film, an output voltage of PZT(70 wt%)/PDMS with CNT (0.5 wt%) was measured.

Transmission Noise Seduction Performance of Smart Panels using Piezoelectric Shunt Damping (압전감쇠를 이용한 압전지능패널의 전달 소음저감 성능)

  • 이중근
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.3 no.1
    • /
    • pp.49-57
    • /
    • 2002
  • The possibility of a transmission noise reduction of piezoelectric smart panels using piezoelectric shunt damping is experimentally studied. Piezoelectric smart panel is basically a plate structure on which piezoelectric patch with shunt circuits is mounted and sound absorbing materials are bonded on the surface of the structure. Sound absorbing materials can absorb the sound transmitted at mid frequency region effectively while the use of piezoelectric shunt damping can reduce the transmission at resonance frequencies of the panel structure. To be able to reduce the sound transmission at low panel resonances, piezoelectric damping using the measured electrical impedance model is adopted. Resonant shunt circuit for piezoelectric shunt damping is composed of register and inductor in series, and they are determined by maximizing the dissipated energy throughout the circuit. The transmitted noise reduction performance of smart panels is investigated using an acoustic tunnel. The tunnel is a tube with square crosses section and a loud-speaker is mounted at one side of the tube as a sound source. Panels are mounted in the middle of the tunnel and the transmitted sound pressure across panels is measured. Noise reduction performance of a smart panels possessing absorbing material and/or air gap shows a good result at mid frequency region but little effect in the resonance frequency. By enabling the piezoelectric shunt damping, noise reduction of 10dB, 8dB is achieved at the resonance frequencise as well. Piezoelectric smart panels incorporating passive method and piezoelectric shunt damping are a promising technology for noise reduction in a broadband frequency.

  • PDF

The Fabrication of SAW Filter Using The GaN Piezoelectric Thin Films (GaN 압전박막을 이용한 SAW 필터 제조)

  • 이석헌;정환희;배성범;최현철;이정희;이용현
    • Proceedings of the IEEK Conference
    • /
    • 2000.06b
    • /
    • pp.5-8
    • /
    • 2000
  • This paper proposes GaN film as a piezoelectric material for SAW(surface acoustic wave) filters. The fabricated GaN SAW filter exhibited a very high velocity of 5800 ㎧and relatively low insertion loss of -9.9 dB without matching circuit. From Smith's equivalent circuit model, the calculated electromechanical coupling factor (K$^2$) was about 4.$\pm$03%. which is larger than those obtained from other thin film piezoelectric materials and allows the realization of wider filter fractional bandwidths.

  • PDF

Selection of Piezoelectric Materials for Ultrasonic Transudcers (초음파 센서를 위한 압전 세라믹 선택)

  • 노용래
    • Proceedings of the Acoustical Society of Korea Conference
    • /
    • 1992.06a
    • /
    • pp.107-110
    • /
    • 1992
  • We investigate the influence of individual properties of piezoceramics such as elastic, dielectric, piezoelectric constants, and the coupling factor on the performance of the transducer operating in thickness mode oscillation. The investigation employs equivalent circuit analysis techniques. Appropriate transfer functions are obtained and discussed which suggest optimum selection guides of piezoelectric ceramics for each purpose, i.e. a transmitter, a receiver, and a pulse-echo transducer. The guides can help ceramic scientists find the direction to proceed in new material development.

  • PDF

An analytical solution to the laminated piezoelectric beam under the electric field

  • Lin, Qirong;Jin, Zhanli;Liu, Zhengxing
    • Structural Engineering and Mechanics
    • /
    • v.10 no.3
    • /
    • pp.289-298
    • /
    • 2000
  • Based on the two-dimensional constitutive relationship of the piezoelastic material, this paper derived an analytic solution to the elastic beam with the piezoelectric layer under the electric field, presented the explicit expressions of its displacement and stress. It is helpful for understanding the electrical and mechanical behavior of piezoelectric materials as actuators and the validation of the numerical methods such as FEM.

An automatic calibration technique for piezoelectric pressure sensors (압전형 압력센서의 교정기법 자동화)

  • Choi, Ju-Ho;Lyou, Joon
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.3 no.4
    • /
    • pp.357-362
    • /
    • 1997
  • This paper suggests an automatic calibration technique for piezoelectric low pressure transducer measuring a pressure blow 500psi. The present calibration system embedded with error correction algorithm generates it's best you don't cut parts of wards like so dynamic pressure and compensates offset voltage and pressure error. It is shown via experimental results that the instrumentation accuracy has been improved and mean time between calibrations has been shortened.

  • PDF