• Title/Summary/Keyword: Micro cantilever

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Parameter Optimization of a Micro-Static Mixer Using Successive Response Surface Method (순차적 반응표면법을 이용한 마이크로 정적 믹서의 최적설계)

  • Han, Seog-Young;Maeng, Joo-Sung;Kim, Sung-Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.9
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    • pp.1314-1319
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    • 2004
  • In this study, parameter optimization of micro-static mixer with a cantilever beam was accomplished for maximizing the mixing efficiency by using successive response surface approximations. Variables were chosen as the length of cantilever beam and the angle between horizontal and the cantilever beam. Sequential approximate optimization method was used to deal with both highly nonlinear and non-smooth characteristics of flow field in a micro-static mixer. Shape optimization problem of a micro-static mixer can be divided into a series of simple subproblems. Approximation to solve the subproblems was performed by response surface approximation, which does not require the sensitivity analysis. To verify the reliability of approximated objective function and the accuracy of it, ANOVA analysis and variables selection method were implemented, respectively. It was verified that successive response surface approximation worked very well and the mixing efficiency was improved very much comparing with the initial shape of a micro-static mixer.

Period doubling of the nonlinear dynamical system of an electrostatically actuated micro-cantilever

  • Chen, Y.M.;Liu, J.K.
    • Smart Structures and Systems
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    • v.14 no.5
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    • pp.743-763
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    • 2014
  • The paper presents an investigation of the nonlinear dynamical system of an electrostatically actuated micro-cantilever by the incremental harmonic balance (IHB) method. An efficient approach is proposed to tackle the difficulty in expanding the nonlinear terms into truncated Fourier series. With the help of this approach, periodic and multi-periodic solutions are obtained by the IHB method. Numerical examples show that the IHB solutions, provided as many as harmonics are taken into account, are in excellent agreement with numerical results. In addition, an iterative algorithm is suggested to accurately determine period doubling bifurcation points. The route to chaos via period doublings starting from the period-1 or period-3 solution are analyzed according to the Floquet and the Feigenbaum theories.

Deflection of a Thin Solid Structure by a Thermal Bubble (열 기포에 의한 고체 박막의 변형 해석)

  • Kim, Ho-Young;Lee, Yoon-Pyo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.2
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    • pp.236-242
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    • 2003
  • Thermal bubbles find their diverse application areas in the MEMS (MicroElectroMechanial Systems) technology, including bubble jet printers, microactuators, micropumps, etc.. Especially, microactuators and micropumps, which use a microbubble growing by a controlled heat input, frequently involve mechanical and thermal interaction of the bubble with a solid structure, such as a cantilever beam and a membrane. Although the concept is experimentally verified that an internal pressure of the bubble can build up high enough to deflect a thin solid plate or a beam, the physics of the entire process have not yet been thoroughly explored. This work reports the experimental study of the growth of a thermal bubble while deflecting a thin cantilever beam. A physical model is presented to predict the elastic response of the cantilever beam based on the experimental measurements. The scaling law constructed through this work can provide a design guide for micro- and nano-systems that employ a thermal bubble for their actuation/pumping mechanism.

Fabrication of a Micro Actuator with p$^+$ Si Cantilevers for Optical Devices (p$^+$ Si 외팔보 구조를 이용한 광학 소자용 마이크로 구동기의 제작)

  • Park, Tae-Gyu;Yang, Sang-Sik
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.5
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    • pp.249-252
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    • 2001
  • The paper represents the design and fabrication of an electrostatic micro actuator with $p^+$,/TEX> Si cantilevers. The micro actuator consists of a plate suspended by four $p^+$,/TEX> silicon cantilevers and an electrode on a glass substrate. The $p^+$,/TEX> Si structure is fabricated by the boron diffusion process and the anisotropic wet etch process. The cantilevers of the micro actuator curl down because of the residual stress gradient in $p^+$,/TEX> silicon. When the electrostatic forec is applied to the $p^+$,/TEX> cantilevers, the vertical displacement of the plate can be achieved. The deflection of the cantilever due to the residual stress gradient and the vertical displacement by electrostatic force were calculated. The displacement of the plate was measured with a laser displacement meter for various input voltages and frequencies. The feasibility of the proposed micro actuator for the applications to optical pickup devices or optical communication devices was confirmed by the experiments.

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A Study on Energy Harvester with Cantilever Structure Using PZT Piezoelectric Material (PZT 압전재료를 이용한 외팔보 구조의 에너지 수집기에 관한 연구)

  • Cha, Doo-Yeol;Lee, Soo-Jin;Chang, Sung-Pil
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.5
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    • pp.416-421
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    • 2011
  • Nowadays, the increasing demands upon mobile devices such as wireless sensor networks and the recent advent of low power electrical devices such as MEMS make such renewable power sources attractive. A vibration-driven MEMS lead zirconate titanate $Pb(Zr,Ti)O_3$ (PZT) cantilever device is developed for energy harvesting application. This paper presents a piezoelectric based energy harvester which is suitable for power generating from conventional vibration and has in providing energy for low power electron ic devices. The PZT cantilever is used d33 mode to get the electrical power. The PZT cantilever based energy harvester with the dimension of 7 mm${\times}$3 mm${\times}$0.03 mm is fabricated using micromachining technologies. This PZT cantilever has the mechanical resonance frequency with a 900 Hz. With these conditions, we get experimentally the 37 uW output power from this device with the application of 1g acceleration using the 900 Hz vibration. From this study, we show the feasibility of one of energy harvesting candidates using PZT based structure. This PZT energy harvester could be used for various applications such a batteryless micro sensors and micro power generators.

Fabrication and Experiment of Piezoelectric Micro Cantilever Applicable to Thrombolysis (혈전분해 응용을 위한 압전형 마이크로 외팔보의 제작 및 실험)

  • Baek, Kun-Hoon;Seo, Young-Tai;Bang, Yong-Seung;Kim, Jong-Man;Kim, Sung-Hyun;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
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    • 2007.11a
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    • pp.152-153
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    • 2007
  • This paper describes a resonant driving piezoelectric micro cantilever practicable to ultrasound thrombolysis device for the treatment of ischemic stroke. The proposed piezoelectric cantilever was designed to be a unimorph structure of Si/$SiO_2$/Ti/Pt/PZT/Pt, and fabricated by top-down sequence etching process. The red blood cell (RBC) lysis experiment was carried out to confirm the usability of the proposed cantilever. Total 87.76 % of RBCs were ruptured using the ultrasound generated by up-down actuations of the fabricated cantilever with AC voltage having the frequency of 19.36 Hz and the magnitude of $30V_{p-p}$.

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Development of electro-spray micro-thruster and measurement of nano-scale thrust (Electro-spray 마이크로 추진 장치 개발 및 나노 크기의 힘 측정)

  • Lee Young-Jong;Si Bui Quang Tran;Byun Do-Young
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2007.04a
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    • pp.45-48
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    • 2007
  • Conventional force sensors such as piezoelectric sensor has limitations for measuring micro/nano-scale thrust. In this study we developed nano-scale measurement system using laser displacement sensor and cantilever. And electrospray microthruster was fabricated by using stainless capillary and extraction electrode, to generate nano-scale thrust. The measurement system can measure the around 90 nN thrust from this thruster. In addition, we designed and fabricated electrospray micro thruster based on PMMA(Polymethyl methacrylate), which has a nozzle protruded from the substrate.

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Characteristics of poly 3C-SiC micro resonators with doping concentrations (도핑농도에 따른 다결정 3C-SiC 마이크로 공진기의 특성)

  • Chung, Gwiy-Sang;Lee, Tae-Won
    • Journal of Sensor Science and Technology
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    • v.18 no.3
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    • pp.207-209
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    • 2009
  • This paper describes the characteristics of poly 3C-SiC micro resonators with $3{\times}10^{17}{\sim}1{\times}10^{19}cm^{-3}$ doping concentrations. The 1.2 ${\mu}m$ thick cantilever and the 0.4 ${\mu}m$ thick doubly clamped beam resonators with different lengths were fabricated using poly 3C-SiC thin films. The characteristics of poly 3C-SiC micro resonators were evaluated by quartz and a laser vibrometer in vacuum at room temperature. The resonant frequencies of micro resonators decreased with doping concentrations owing to reduction in the Young's modulus of poly 3C-SiC thin films. It was confirmed that the resonant frequencies of poly 3C-SiC resonators are controllable by doping concentrations. Therefore, poly 3C-SiC resonators could be applied to MEMS devices and bio/chemical sensor applications.

A Study on the Fabrication and Characterization of Micro Pb(Zr,Ti)O3 Film Piezoelectric Cantilever Using MEMS Process for Energy Harvesting (MEMS 공정을 통한 마이크로 Pb(Zr,Ti)O3 박막 압전 외팔보 에너지 수확소자의 제작 및 특성 연구)

  • Lee, Junmyung;Chun, Inwoo;Kim, Moonkeun;Kwon, Kwang-Ho;Lee, Hyun Woo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.11
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    • pp.831-835
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    • 2013
  • In this study, we fabricated a micro $Pb(Zr,Ti)O_3$ (PZT) film piezoelectric cantilever with a Si proof mass and dual beams through MEMS process. The size of the beam and the integrated Si proof mass were about $4,320{\mu}m{\times}290{\mu}m{\times}12{\mu}m$ and $1,380{\mu}m{\times}880{\mu}m{\times}450{\mu}m$ each. To reduce the air damping and have the larger displacement of dual beams was used for design. After mounting micro PZT film piezoelectric cantilever on shaker, we measured the resonance frequency and a output voltage while making resonant frequency changed. The resonant frequency and the highest average power of the cantilever device were 110.2 Hz and 0.36 ${\mu}W$ each, at 0.8 g acceleration and 23.7 $k{\Omega}$ load resistance, respectively.