• Title/Summary/Keyword: piezoelectric signal

Search Result 228, Processing Time 0.033 seconds

Development of an Electrostatic Drop-On-Demand inkjet Device for Display Fabrication Process

  • Son, Sang-Uk;Choi, Jae-Yong;Lee, Suk-Han;Kim, Yong-Jae;Ko, Han-Seo;Kim, Hyun-Cheol;Byun, Do-Young
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2006.08a
    • /
    • pp.655-659
    • /
    • 2006
  • This paper presents a novel electrostatic drop-on-demand inkjet device featured by a MEMS fabricated pole-type and hole-type nozzle with tube shaped orifice and investigates the feasibility of applying the inkjet device to display fabrication process. The electric voltage signal applied to the ring shaped upper electrode plate, against the hole-shaped ground or pole-shaped ground, referred here pole-type and hole-type nozzle respectively, allows ejection of small droplet to take place: That is, a tiny droplet is taken away from the peak of the mountain shaped liquid meniscus formed at the nozzle orifice. It is verified experimentally that the use of the pole type nozzle allows a stable and sustainable micro-dripping mode of droplet ejection for a wider range of applied voltages and of liquid viscosities. This demonstrates a feasibility of electrostatic drop-on-demand inkjet device as a disruptive alternative to conventional print heads such as thermal bubble or piezoelectric inkjet heads.

  • PDF

Automated Surface Wave Measurements for Evaluating the Depth of Surface-Breaking Cracks in Concrete

  • Kee, Seong-Hoon;Nam, Boohyun
    • International Journal of Concrete Structures and Materials
    • /
    • v.9 no.3
    • /
    • pp.307-321
    • /
    • 2015
  • The primary objective of this study is to investigate the feasibility of an innovative surface-mount sensor, made of a piezoelectric disc (PZT sensor), as a consistent source for surface wave velocity and transmission measurements in concrete structures. To this end, one concrete slab with lateral dimensions of 1500 by 1500 mm and a thickness of 200 mm was prepared in the laboratory. The concrete slab had a notch-type, surface-breaking crack at its center, with depths increasing from 0 to 100 mm at stepwise intervals of 10 mm. A PZT sensor was attached to the concrete surface and used to generate incident surface waves for surface wave measurements. Two accelerometers were used to measure the surface waves. Signals generated by the PZT sensors show a broad bandwidth with a center frequency around 40 kHz, and very good signal consistency in the frequency range from 0 to 100 kHz. Furthermore, repeatability of the surface wave velocity and transmission measurements is significantly improved compared to that obtained using manual impact sources. In addition, the PZT sensors are demonstrated to be effective for monitoring an actual surface-breaking crack in a concrete beam specimen subjected to various external loadings (compressive and flexural loading with stepwise increases). The findings in this study demonstrate that the surface mount sensor has great potential as a consistent source for surface wave velocity and transmission measurements for automated health monitoring of concrete structures.

Active Noise Control Using Sensory Actuator (자기감응 액추에이터를 이용한 능동소음제어)

  • Go, Byeong-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.20 no.5
    • /
    • pp.1573-1581
    • /
    • 1996
  • This paper present as experimental demonstratio of DSP and a sensory actuator that is used to actively control sound transmission/radiation through a vibrating plate. A plane acoustic wave incident on a clamped, thin circular plate was used as a noise source, and a sensory actuator bounded to the plate was used to control and sense vibration of the plate. The sound transmission reduction problem was tranformed as a structural vibration control problem that actively control the structural vibration modes coupled to acoustic modes. The results show that the first structural vibration mode is controlled with a reduction of 78 percent in the displacement and velocity of the plate. This corresponds to a 13dB reduction in the acoustic response. These experimental results indicate that a sensory actuator bounded to the plate can be employed to attenuate the sound transmitted to radiated from the plate.

Design of a Ultrasonic Cutting-tool Utilizing Resonance Condition of Transverse Vibration of Beam Type Structure (보의 횡진동 공진특성을 이용한 초음파 진동절삭공구 설계)

  • Byun, Jin-Woo;Han, Sang-Bo
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.21 no.8
    • /
    • pp.720-725
    • /
    • 2011
  • Most ultrasonic vibration cutting tools are operated at the resonance condition of the longitudinal vibration of the structure consisting of booster, horn and bite. In this study, a transverse vibration tool with beam shape is designed to utilize the vibration characteristics of the beam. Design point of the transverse vibration tool is to match the resonance frequency of the bite to the frequency of the signal to excite the piezoelectric element in the booster. The design process to match the natural frequency of the longitudinal vibration mode of the horn and that of the transverse vibration mode of the bite is presented. Dimensions of the horn and bite are searched by trend analysis through which the standard shapes of the horn and bite are determined. After the dimensions of each component of the cutting tool consisting of booster, horn and bite are determined, the assembled structure was experimentally tested to verify that true resonant condition is achieved and proper vibrational displacement are obtained to ensure that enough cutting force is generated.

Modeling and Vibration Control of the Miniature Universal Testing Machine (소형 재료시험기의 모델링 및 진동 제어)

  • Bok, Jin;Kim, Yeung-Shik;Kweon, Hyeon-kyu;Kim, In-Soo;Choi, Seong-Dae
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.15 no.3 s.96
    • /
    • pp.290-296
    • /
    • 2005
  • This paper proposes the modeling scheme of the Miniature Universal Testing Machine (MUTM) composed of 36 thin-beam-type bimorph PZTs and the control algorithm to minimize the residual vibration of the MUTM in the dynamic testing of specimens. In the operation of the MUTM, hysteresis, residual displacement and vibration of it are major issues. From the analysis of the MUTM behaviors, the hysteresis is described by the curving fitting scheme with the function of an input voltage. The dynamic characteristics of the MUTM are identified by the frequency domain modeling technique based on the experimental data. The interested bandwidth is focused on 125-315HZ for effective modeling and control. For the robust vibration control of the MUTM, the sliding mode control and the Kalman filter as observer are proposed. The paper also proposes the best input signal type to operate the MUTM effectively. The feasibility of the proposed modeling scheme and control algorithm are tested and verified experimentally.

Micro Patterning of Nano Metal Ink for Printed Circuit Board Using Inkjet Printing Technology (잉크젯 프린팅 기술을 이용한 나노 금속잉크의 인쇄회로기판용 미세배선 형성)

  • Park, Sung-Jun;Seo, Shang-Hoon;Joung, Jae-Woo
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.24 no.5
    • /
    • pp.89-96
    • /
    • 2007
  • Inkjet printing has become one of the most attractive manufacturing techniques in industry. Especially inkjet printing technology will soon be part of the PCB (Printed Circuit Board) fabrication processes. Traditional printing on PCB includes screen printing and photolithography. These technologies involve high costs, time-consuming procedures and several process steps. However, by inkjet technology manufacturing time and production costs can be reduced, and procedures can be more efficient. PCB manufacturers therefore willingly accept this inkjet technology to the PCB industry, and are quickly shifting from conventional to inkjet printing. To produce the printed circuit board by the inkjet technology, it must be harmonized with conductive nano ink, printing process, system, and inkjet printhead. In this study, micro patterning of conductive line has been investigated using the piezoelectric printhead driven by a bipolar voltage signal is used to dispense 20-40 ${\mu}m$ diameter droplets and silver nano ink which consists of 1 to 50 nm silver particles that are homogeneously suspended in an organic carrier. To fabricate a conductive line used in PCB with high precision, a printed line width was calculated and compared with printing results.

Tip Position Command Tracking of a Flexible Beam Using Active Vibration Control (능동진동제어를 이용한 유연보의 끝단위치 명령추종연구)

  • Lee, Young-Sup;Elliott, Stephen-J
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2003.11a
    • /
    • pp.643-648
    • /
    • 2003
  • The problem considered in this paper is that the tip position of a flexible cantilever beam is controlled to follow a command signal, using a pair of piezoelectric actuators at the clamped end. The beam is lightly damped and so the natural transient response is rather long, and also since the sensor and actuator are not collocated, the plant response is non-minimum phase. Two control strategies were investigated. The first involved conventional PID control in which the feedback gains were adjusted to give the fastest closed-loop response to a step input. The second control strategy was based on an internal model control (IMC) architecture. The control filter in the IMC controller was a digital FIR device designed to minimize the expectation of the mean square tracking error. The IMC controller designed fur the beam was found to have very much reduced settling times to a step input compared with those of the PID controller.

  • PDF

Investigation of Generative Contactile Force of Frog Muscle under Electrical Stimulation

  • Park, Suk-Ho;Jee, Chang-Yeol;Kwon, Ji-Woon;Park, Sung-Jin;Kim, Byung-Kyu;Park, Jong-Oh
    • Journal of Mechanical Science and Technology
    • /
    • v.20 no.11
    • /
    • pp.1914-1919
    • /
    • 2006
  • Recently, the microrobots powered by biological muscle actuators were proposed. Among the biological muscle actuators, frog muscle is well known as a good muscle actuator and has a large displacement, actuation forces and piezoelectric properties. Therefore, for the application of the biomimetic microrobot, this paper reports the electromechanical properties of frog muscle. First of all, the experimental setup has been established for measuring generative force of the frog muscle. Through the various electrical stimulating inputs to the frog muscle, we measured the contractile force of the frog muscle. From the measuring results, we found that the actuating contractile force responses of the frog muscle are determined by the amplitude, frequency, duty ratio, and wave form of the stimulation signal. This study will be beneficial for the development of the microrobot actuated by frog muscle.

Fabrication of an On System based on an Optical Delay line with Cylindrical PZT (실린더형 압전소자 광지연선을 이용한 광 간섭형 단층촬영(OCT) 시스템 제작)

  • Park, Sung-Jin;Kim, Young-Kwan;Kim, Yong-Pyung
    • Korean Journal of Optics and Photonics
    • /
    • v.17 no.2
    • /
    • pp.159-164
    • /
    • 2006
  • We demonstrate a compact optical coherence tomography(OCT) system based on the optical fiber delay line controlled by a cylindrical piezo-electric transducer(PZT). An 18-m length of single mode fiber is wrapped under constant tension around a PZT. Approximately 134 windings are used. Wraps of the long length of fiber allow the small expansion of the PZT to be magnified to an optical path length delay of 0.78 m. The OCT system shows characteristics for 2-dimensional imaging, exhibiting 96.9dB of signal-to-noise ratio(SNR), $18.6{\pm}0.5\;{\mu}m$ of axial resolution, and $5\;{\mu}m$ of lateral resolution with samples.

Development of Batteryless SAW-based Integrated Microsensor and Wireless Measurement Technique (무전지 SAW 기반 마이크로 통합센서 및 무선 측정기술 개발)

  • Oh, Hae-Kwan;Kim, Tae-Hyun;Wang, Wen;Yang, Sang-Sik;Lee, Kee-Keun
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.56 no.8
    • /
    • pp.1430-1435
    • /
    • 2007
  • We developed a 440MHz surface acoustic wave (SAW) microsensor integrated with pressure-temperature sensors and ID tag. Two piezoelectric substrates were bonded, in which ${\sim}150\;{\mu}m$ cavity was structured. Four sides were completely sealed by JSR photoresist (PR). Pressure sensor was placed on the top substrate, whereas ill tag and temperature sensor were placed on the bottom substrate. Using network analyzer, the developed microsensor was wirelessly tested. Sharp reflection peaks with high S/N ratio, small signal attenuation, and small spurious peaks were observed. All the reflection peaks were well matched with the coupling of mode (COM) simulation results. With a 10mW RF power from the network analyzer, a ${\sim}1$ meter readout distance was observed. Eight sharp ON reflection peaks were observed for ID tag. Temperature sensor was characterized from $20^{\circ}C$ to $200^{\circ}C$. A large phase shift per unit temperature change was observed. The evaluated sensitivity was ${\sim}10^{\circ}/^{\circ}C$.