• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.11a
• /
• pp.404-407
• /
• 2004

Linear ultrasonic motor by bimorph. Transducer for linear ultrasonic motor with symmetric and anti-symmetric modes was studied. The transducer was composed of two piezoelectric ceramic that cross at right angles with each other at tip. In order to exist length vibration mode two piezoelectric ceramics must have 90-degree phase difference with each other. As a result, tip of transducer moves in elliptical motion. Elliptical trajectory of transducer was analyzed by employing the (mite element method(FEM). From the result, the linear ultrasonic motor was measured for characteristics. In this paper, vibration shape of transducer was simulated and the resonant frequency, stabilization frequency and maximum displacement were calculated using the FEA.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.322-322
• /
• 2010

In this paper, we propose a novel type valveless micro-pump that uses extensional vibration mode of traveling wave as a volume transporting means for solving some problems about check valves, essential parts of usual pumps. The proposed pump consists of two piezoelectric ceramic rings and a metal body located in the middle of them respectively. Because the drift of bended surface that results from the traveling wave excitation controls the fluid flow, check valves are not needed in this pump model. In accordance with the variation of the pump body dimension, we analyzed the vibration displacement characteristics of pump model, determined the optimal design condition, fabricated the prototype pump from the analysis results and evaluated its efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.215-216
• /
• 2008

Using the extensional vibration mode of PZT ring, a piezopump is successfully made. The PZT ring is polarized with thickness direction. The traveling extensional wave along the circumference of the ring is obtained by dividing two standing waves which are temporally and spatially phase shifted by 90 degrees from each other. The proposed piezopump is consisted of coaxial cylindrical shells that are bonded piezoelectric ceramic ring.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.4
• /
• pp.286-289
• /
• 2012

In this paper, we have proposed piezoelectric energy harvester employing the pillar structure with the diameter size of 500 um. So we have selected the Su-8 photo-resist and modified lithography process to manufacture the pillar structure with height above the $500{\mu}m$. Simultaneously, we tried to make a comparative study to use ceramic bulk - polymer structure In this paper, we will report the process and properties of micro pillar structure based on the PMN-PZT ($Pb(Mg_{1/3}Nb_{2/3})O_3-PbZrTiO_3$) materials. Finally, We will propose a method for generating electrical energy with a piezoelectric element using vibration, an energy source can be obtained from the "clean" energy.

• Journal of Mechanical Science and Technology
• /
• v.15 no.1
• /
• pp.61-65
• /
• 2001

Using the theory of linear piezoelectricity, the problem of two layered strip with a piezoelectric ceramic bonded to an elastic material containing a finite interface crack is considered. The out-of-plane mechanical and in-plane electrical loadings are simultaneously applied to the strip. Fourier transforms are used to reduce the problem to a pair of dual integral equations, which is then expressed in terms of a Fredholm integral equation of the second kind. The stress intensity factor is determined, and numerical analyses for several materials are performed and discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.290-291
• /
• 2007

In this study, in order to develop the low temperature sintering multilayer piezoelectric actuator, PZW-PMN-PZT system ceramics were manufactured according to variation of sintering aids. At the sintering temperature of $900^{\circ}C$, $0.3wt%Li_2CO_3$, $0.2wt%Bi_2O_3$ and 0.2wt%CuO added specimen showed a maximum value of kp = 0.552, $d_{33}\;=\;344pC/N$ and Qm = 1320, respectively.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.10
• /
• pp.2172-2179
• /
• 2002

In this paper, we examine the dynamic electromechanical behavior of an edge crack in a piezoelectric ceramic layer bonded between two elastic layers under the combined anti-plane mechanical shear and in-plane electric transient loadings. We adopted both the permeable and impermeable crack boundary conditions. Fourier transforms are used to reduce the problem to the solution of two pairs of dual integral equations, which are then expressed to a Fredholm integral equation of the second kind. Numerical values on the dynamic energy release rate are presented to show the dependences upon the geometry, material combination, electromechanical coupling coefficient and electric field.

• Transactions on Electrical and Electronic Materials
• /
• v.1 no.3
• /
• pp.1-5
• /
• 2000

This paper presents a new sort of multilayer piezoelectric ceramic transformer for switching regulation power supplies. This piezoelectric transformer operate in the second thickness resonant vibration mode. Accordingly its resonant frequency is higher than 1 NHz, Because output power is low if input and output part of transformer are consisted of single layer, this research suggests a new method, which is consisted of both input and output part of transformer have 2-layered piezoelectric ceramics, The size of transformer is 20 mm in width and length, and 1.4 mm in thickness, respectively, To design a high efficient switching circuit of the transformer, internal circuit parameters were measured and then weve calculated a parameter of inductor nd capacitor to design a driving circuit, Weve used a MISFET and its driver circuit modified a calp oscillator circuit as the primary switching circuit.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.7
• /
• pp.644-649
• /
• 2006

This paper presents a new disk-type piezoelectric transformer. The input side of the transformer has a crescent-shaped electrode and the output side has a focused poling direction. The piezoelectric transformers operated in each transformer's resonance vibration mode. The electrodes and poling directions on commercially available piezoelectric ceramic disks were designed so that the planar or shear mode coupling factor $(k_p\;k_{15})$ becomes effective rather than the transverse mode coupling factor $(k_{31})$. ANSYS finite element code was used to analyze transformer behavior and to optimize electrode and poling configurations. The voltage step-up ratio of the proposed transformer has been markedly improved in comparison with that of the equivalent rectangular(Rosen) type. A single layer prototype transformer, $20\sim30mm$ in diameter and $1.0\sim3.5mm$ thick, was fabricated, such as step-up ratio, power transformation efficiency, and temperature were measured. While the transformer was driving a Cold Cathode Fluorescent Lamp(CCFL), the temperature field of the transformer was also observed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.3
• /
• pp.222-227
• /
• 2006

RAINBOW(Reduced And Internally Biased Oxide Wafers) are a new class of high-displacement, piezoelectric actuator produced by selectively removing oxygen from one surface of ceramic using a high-temperature chemical reduction process. In this paper, RAINBOW actuator materials of $0.4Pb(Ni_{1/3}Nb_{2/3})O_3-0.6Pb(Zr_{x}Ti_{1-x})O_3$ ceramics were prepared. Its dielectric and piezoelectric properties were investigated in the vicinity of MPB. The piezoelectric properties showed the maximum value of ${\epsilon}r$ = 4871, $d_{33}$ = 610 ($10^{-12}$ m/V), $d_{31}$ = -299 ($10^{-12}$ m/V), $k_{33}$ = $71\%$, Qm = 70, in $0.4Pb(Ni_{1/3}Nb_{2/3})O_{3}-0.6Pb(Zr_{405}Ti_{595})O_3$ composition sintered at $1250^{\circ}C$. The strain - electric field characteristics of RAINBOW actuator were significantly improved comparison with the conventional bulk actuator. The prepared RAINBOW actuator showed about $390\;{\mu}m/100\;V$ displacement.