• 제목/요약/키워드: Piezo devices

검색결과 41건 처리시간 0.027초

전자기 전항을 이용한 압전 구동방식 마이크로 펌프의 유동 및 성능 특성에 관한 수치해석적 연구 (A Numerical Study on the Flow and Performance Characteristics of a Piezoelectric Micropump with Electromagnetic Resistance for Electrically Conducting Fluids)

  • 안용준;최청렬;김창녕
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2788-2793
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    • 2008
  • A numerical analysis has been conducted for flow characteristics and performance of a micropump with piezodisk and MHD(Magnetohydrodynamics) fluid. Various micro systems which could not be considered in the past have been recently growing with the development of MEMS(Micro Electro Mechanical System) and micro machining technology. Especially, micropumps, essential part of micro fluidic devices, are being lively studies by many researchers. In the present study, the piezo electric micropump with electromagnetic resistance for electrically conducting fluids is considered. The prescribed grid deformation method is used for the displacement of the membrane. The change of the performance of the micropump and flow characteristics of the electrically conducting fluid with the magnitude of the magnetic fields, duct size, the position of the inlet and outlet duct are investigated in the present study.

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압전소자 구동장치를 이용한 로봇 손목기구의 개발 (Development of a robot wrist using a piezo actuator)

  • 조영화;문창렬;조형석
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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    • pp.528-532
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    • 1991
  • Having very small linear displacement, piezoelectric actuators have been restricted in robotic application as positioning devices. In this paper, a mechanical amplifier was developed to enhance the displacement of piezoelectric actuator and the corresponding driving circuit was designed. This equipment was integrated as a robotic wrist having 2 D.O.F micropositioning capability. Each joint was analysed in mechanical and dynamic view points. Experimental result showed that this device has Some hysteresis but could be used as vibratory robotic wrist with relatively high frequency. For more fine positioning control, a closed loop approach must be taken into account.

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물리적 인간 기계 상호작용을 위한 근육의 기하학적 형상 변화를 이용한 상지부 움직임 예측 (Prediction of the Upper Limb Motion Based on a Geometrical Muscle Changes for Physical Human Machine Interaction)

  • 한효녕;김정
    • 제어로봇시스템학회논문지
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    • 제16권10호
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    • pp.927-932
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    • 2010
  • Estimation methods of motion intention from bio-signal present challenges in man machine interaction(MMI) to offer user's command to machine without control of any devices. Measurements of meaningful bio-signals that contain the motion intention and motion estimation methods from bio-signal are important issues for accurate and safe interaction. This paper proposes a novel motion estimation sensor based on a geometrical muscle changes, and a motion estimation method using the sensor. For estimation of the motion, we measure the circumference change of the muscle which is proportional to muscle activation level using a flexible piezoelectric cable (pMAS, piezo muscle activation sensor), designed in band type. The pMAS measures variations of the cable band that originate from circumference changes of muscle bundles. Moreover, we estimate the elbow motion by applying the sensor to upper limb with least square method. The proposed sensor and prediction method are simple to use so that they can be used to motion prediction device and methods in rehabilitation and sports fields.

피에조 잉크젯 헤드에서 액적 토출 현상에 대한 연구 (A Study on Droplet Formation from Piezo Inkjet Print Head)

  • 오세영;이정용;이유섭;정재우;위상권
    • 대한기계학회논문집B
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    • 제30권10호
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    • pp.1003-1011
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    • 2006
  • Droplets are ejected onto a substrate through a nozzle by pushing liquids in flow channels of drop-on-demand devices. The behavior of ejection and formation of droplets is investigated to enhance the physical understanding of the hydrodynamics involved in inkjet printing. The free surface phenomenon of a droplet is described using $CFD-ACE^{TM}$ which employs the volume-of-fluid (VOF) method with the piecewise linear interface construction (PLIC). Droplet formation characteristics are analyzed in various flow regimes with different Ohnesorge numbers. The computational results show that the droplet formations are strongly dependent on the physical properties of working fluids and the inlet flow conditions. In addition, the wetting characteristics of working fluids on a nozzle influence the volume and velocity of a droplet produced in the device. This study may provide an insight into how a liquid droplet is formed and ejected in a piezoelectric inkjet printing device.

함정용 능동 하이브리드 마운트 개발에 대한 연구 (A Study on Development of an Active Hybrid Mount for Naval Ships)

  • 문석준;지용진;윤정식;최승복;이현엽;김재호;정우진
    • 대한조선학회논문집
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    • 제45권3호
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    • pp.288-295
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    • 2008
  • Passive-type control devices such as resilient mounts and wire rope isolators are generally used for protecting the shipboard equipment from shock loading and for suppressing the mechanical vibration of the equipment in naval ships. To improve the performance of the control device, a new hybrid mount is under development in this study. This mount consists of a passive-type rubber element and an active-type piezo-stack element. It can be expected that the mount has enhanced performance of about 20 dB or more with respect to transmissibility through a series of performance tests of prototype mount.

압전 및 비압전 폴리머와 BaTiO3 나노입자로 제조된 유-무기 압전 나노복합체의 발전성능 비교연구 (A Comparison Study of Output Performance of Organic-Inorganic Piezoelectric Nanocomposite Made of Piezoelectric/Non-piezoelectric Polymers and BaTiO3 Nanoparticles)

  • 현동열;박귀일
    • 한국분말재료학회지
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    • 제26권2호
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    • pp.119-125
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    • 2019
  • Piezoelectric energy harvesting technology is attracting attention, as it can be used to convert more accessible mechanical energy resources to periodic electricity. Recent developments in the field of piezoelectric energy harvesters (PEHs) are associated with nanocomposites made from inorganic piezoelectric nanomaterials and organic elastomers. Here, we used the $BaTiO_3$ nanoparticles and piezoelectric poly(vinylidene fluoride) (PVDF) polymeric matrix to fabricate the nanocomposites-based PEH to improve the output performance of PEHs. The piezoelectric nanocomposite is produced by dispersing the inorganic piezo-ceramic nanoparticles inside an organic piezo-polymer and subsequently spin-coat it onto a metal plate. The fabricated organic-inorganic piezoelectric nanocomposite-based PEH harvested the output voltage of ~1.5 V and current signals of ~90 nA under repeated mechanical pushings: these values are compared to those of energy devices made from non-piezoelectric polydimethylsiloxane (PDMS) elastomers and supported by a multiphysics simulation software.

Removal of Flooding in a PEM Fuel Cell at Cathode by Flexural Wave

  • Byun, Sun-Joon;Kwak, Dong-Kurl
    • Journal of Electrochemical Science and Technology
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    • 제10권2호
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    • pp.104-114
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    • 2019
  • Energy is an essential driving force for modern society. In particular, electricity has become the standard source of power for almost every aspect of life. Electric power runs lights, televisions, cell phones, laptops, etc. However, it has become apparent that the current methods of producing this most valuable commodity combustion of fossil fuels are of limited supply and has become detrimental for the Earth's environment. It is also self-evident, given the fact that these resources are non-renewable, that these sources of energy will eventually run out. One of the most promising alternatives to the burning of fossil fuel in the production of electric power is the proton exchange membrane (PEM) fuel cell. The PEM fuel cell is environmentally friendly and achieves much higher efficiencies than a combustion engine. Water management is an important issue of PEM fuel cell operation. Water is the product of the electrochemical reactions inside fuel cell. If liquid water accumulation becomes excessive in a fuel cell, water columns will clog the gas flow channel. This condition is referred to as flooding. A number of researchers have examined the water removal methods in order to improve the performance. In this paper, a new water removal method that investigates the use of vibro-acoustic methods is presented. Piezo-actuators are devices to generate the flexural wave and are attached at end of a cathode bipolar plate. The "flexural wave" is used to impart energy to resting droplets and thus cause movement of the droplets in the direction of the traveling wave.

Examining the qualification of copper magnetic nanocatalyst design and its application in piezoelectric sensor

  • Yufeng Pang;Xiaojuan Li
    • Structural Engineering and Mechanics
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    • 제85권6호
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    • pp.743-753
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    • 2023
  • Piezoelectricity is defined as the ability of certain materials to produce electric signals when mechanically stressed or to deform when an electrical potential is applied. Piezo technology is becoming increasingly crucial as intelligent devices use vibration sensors to detect vibrations in consumer electronics, the automotive industry, architectural design, and other applications. A wide range of applications is now possible with piezoelectric sensors, such as skin-attachable devices that monitor health and detect diseases. In this article, copper nanoparticles are used in the piezoelectric sensor as the driving agent of the magnetic field. Magnetic nanocatalysts containing copper nanoparticles are used due to their cheapness and availability. Considering that the increase of the electric field acting on the piezoelectric increases the damping (As a result, damping materials reduce radiation noise and increase material transfer losses by altering the natural vibration frequency of the vibrating surface). Among the advantages of this method are depreciating a significant amount of input energy using high energy absorption capacity and controlling slight vibrations in the sensors.

압전-마찰전기 복합 소재 기반의 고출력 에너지 하베스팅 기술 개발 리뷰 (Review on the Recent Advances in Composite Based Highoutput Piezo-Triboelectric Energy Harvesters)

  • ;박현제;손민균;이태형;강대준
    • 세라미스트
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    • 제23권1호
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    • pp.54-88
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    • 2020
  • Global effort has resulted in tremendous progress with energy harvesters that extract mechanical energy from ambient sources, convert it to electrical energy, and use it for systems such as wrist watches, mobile electronic devices, wireless sensor nodes, health monitoring, and biosensors. However, harvesting a single energy source only still pauses a great challenge in driving sustainable and maintenance-free monitoring and sensing devices. Over the last few years, research on high-performance mechanical energy harvesters at the micro and nanoscale has been directed toward the development of hybrid devices that either aim to harvest mechanical energy in addition to other types of energies simultaneously or to exploit multiple mechanisms to more effectively harvest mechanical energy. Herein, we appraise the rational designs for multiple energy harvesting, specifically state-of-the-art hybrid mechanical energy harvesters that employ multiple piezoelectric and triboelectric mechanisms to efficiently harvest mechanical energy. We identify the critical material parameters and device design criteria that lead to high-performance hybrid mechanical energy harvesters. Finally, we address the future perspectives and remaining challenges in the field.

HMD용 발향장치 설계와 적용 (Application and Design of Scent Display Device for Head-Mounted Display)

  • 백민호;김민구;금동위;김정도
    • 센서학회지
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    • 제28권1호
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    • pp.52-57
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    • 2019
  • Studies to augment emotion and immersion in multimedia content through olfactory stimulation are being increasingly conducted in the past two decades, and a variety of scent devices have been developed. Most of the scent devices are very large and heavy; consequently, they are installed on a table rather than being attached to the Head-mounted Display (HMD). Even if such devices are mounted on the HMD, it is not possible to control the scent density because of the size limitation, and it is not easy to be immersed in the experience because of the noise caused by the scent device. In order for an actual virtual reality or an augmented reality system to work efficiently with the scent device, three conditions - noiseless, a compact design, and concentration control- must be satisfied. In this study, we design a scent device that satisfies these three conditions. By using a miniature piezoelectric pump, a small size scent device is designed so that it can be easily attached to the lower end of the HMD, and hardly any noise is generated. Moreover, it is possible to control the concentration of the scent by controlling the piezoelectric pump using amplitude and frequency.