Search for: micro-actuation
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    Analytical modeling of the effects of electrostatic actuation and casimir force on the pull-in instability and static behavior of torsional nano/micro actuators

    , Article International Journal of Modern Physics B ; Volume 27, Issue 6 , 2013 ; 02179792 (ISSN) Moeenfard, H ; Darvishian, A ; Ahmadian, M. T ; Sharif University of Technology
    This paper studies the effect of Casimir force on the pull-in instability of electrostatically actuated torsional nano/micro actuators. Dependence of the actuator's pull-in angle and pull-in voltage on several design parameters are investigated and it is found that Casimir force can considerably reduce the stability limits of the torsional actuators. Nonlinear equilibrium equation is solved numerically and analytically using straight forward perturbation expansion method. It is observed that a fourth-order perturbation approximation can precisely model the behavior of a torsional actuator. The results of this paper can be used for safe and stable design of torsional nano/micro actuators  

    Fabrication, Visualization and Calibration of a Novel TEM Microactuator

    , M.Sc. Thesis Sharif University of Technology Takht Abnousi, Marjan (Author) ; Alasti, Aria (Supervisor)
    Nowadays precise nano positioning plays an important role in micro systems. Precise positioning at nano scale plays a basic role in nano science such as micro -robotics, solid state physics and photonics. Manipulating matter in a molecular scale creates a dramatic change and restruturing in macro scale engineering. During this research a novel TEM micro actuator is designed and fabricated based on calibration criteria. This structure was fabricated with SOI wafer (silicon on insulator) in micro scale level for the first time in Iran. This compliant consists of 12 TEM actuators end in 3DOF (In-plane) motion. The new micro actuator operates based on the thermal expansion due to voltage. Each... 

    Fabrication of A Compliant Based 6-DOF Micro Actuator

    , M.Sc. Thesis Sharif University of Technology Akrami, Mohammad Reza (Author) ; Alasty, Areya (Supervisor)
    Currently, precision positioning plays a pivotal role in technology. The need for accurate positioning in applications such as robotics, optoelectronics and micro and nano technology increases day by day. To begin with, we wanted to make a miniature prototype of a micro actuator but in this regard, we are faced with several problems. Some major problems were the high cost of this prototype plus the fact that we did not have the necessary equipment with acceptable resolution for making such a system, so we decided to decrease the scale and build it in micro scale which is accessible for us. The main idea and design of this micro actuator is by Mrs. Akbari. During this project, the researcher... 

    Development, modeling and deflection analysis of hybrid micro actuator with integrated thermal and piezoelectric actuation

    , Article Meccanica ; Volume 48, Issue 5 , 2013 , Pages 1081-1091 ; 00256455 (ISSN) Pourrostami, H ; Zohoor, H ; Kargarnovin, M. H ; Sharif University of Technology
    Micro actuators are irreplaceable part of motion control in minimized systems. The current study presents an analytical model for a new Hybrid Thermo Piezoelectric micro actuator based on the combination of piezoelectric and thermal actuation mechanisms. The micro actuator structure is a double PZT cantilever beam consisting of two arms with different lengths. The presented micro actuator uses the structure of electrothermal micro actuator in which polysilicon material is replaced by PZT. Also the voltage and poling directions are considered in the lengthwise of PZT beams. As a result, the piezoelectric actuation mechanism is based on d33 strain coefficient. The tip deflection of micro... 

    Control of planar motion of a magnetic microrobot using a novel electromagnetic actuation system

    , Article 4th International Conference on Manipulation, Automation, and Robotics at Small Scales, MARSS 2019, 1 July 2019 through 5 July 2019 ; 2019 ; 9781728109473 (ISBN) Yousefi, M ; Moradi, A ; Nejat Pishkenari, H ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    A magnetic actuation system is a promising tool for untethered manipulation at the microscale that medical treatment can benefit from. This paper proposes a new magnetic actuation system that comprises of two coaxial coils on a rotary table. A fixed workspace is placed between coils. The proposed system is able to generate magnetic force with desired direction and magnitude in a plane. The conducted simulation and experiment confirm the capability of the proposed system to control the position of the microrobot. © 2019 IEEE  

    Dynamic finite element modeling of electrostatical actuated micro structures considering squeeze film damping effect

    , Article 2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006, Chicago, IL, 5 November 2006 through 10 November 2006 ; 2006 ; 1096665X (ISSN); 0791837904 (ISBN); 9780791837900 (ISBN) Ahmadian, M. T ; Borhan, H ; Moghimi Zand, M ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2006
    Developing a transient fully-meshed model of coupled-domain microsystems is of paramount importance not only for accurate simulation and design but also for creating more accurate low-order or macro dynamic models. So in this paper, a complete nonlinear finite element model for coupled-domain MEMS devices considering electrostatic and squeeze film effects is presented. For this purpose, we use the Galerkin weighted-residual technique for developing the finite element model that capture the original microsystem's nonlinear behaviors, such as the structural dynamics, the squeeze-film damping, the electrostatic actuation and the geometric nonlinearity caused by inherent residual stresses. In... 

    Multi-objective optimization of piezoelectric microactuator using genetic algorithms

    , Article 2008 ASME International Mechanical Engineering Congress and Exposition, IMECE 2008, Boston, MA, 31 October 2008 through 6 November 2008 ; Volume 13, Issue PART B , 2009 , Pages 723-730 ; 9780791848746 (ISBN) Esteki, H ; Hasannia, A ; Sharif University of Technology
    In flex-tensional piezoactuators, due to the low displacement of piezostacks, a compliant mechanism is used to amplify displacement of piezostack. In this paper, optimization of a compliant mechanism with corner-filleted flexure hinges is carried out using real-coded genetic algorithms (GAs) to avoid trapping in local optimums. The objective functions are displacement amplification and stiffness of mechanism and design variables are cross-sectional size and material used. The constraints which are applied on mechanism are based on piezostack dimensions and manufacturing limits. Displacement amplification and stiffness are calculated using strain energy and Castigliano's displacement theorem.... 

    Optimum design and vibration suppression of a piezoelectric amplified microactuator using FEM analysis

    , Article s20th International Microprocesses and Nanotechnology Conference, MNC 2007, Kyoto, 5 November 2007 through 8 November 2007 ; February , 2007 , Pages 378-379 ; 4990247248 (ISBN); 9784990247249 (ISBN) Mahboobi, H ; Shahidi, A ; Pirouzpanah, S ; Esteki, H ; Sarkar, S ; Sharif University of Technology
    In this research the optimum design of a piezoelectric amplified microactuator has been achieved via equation (1) and sensitivity analysis in FEM simulation software. In addition, for the sake of simplicity and utilizing the FEM software simulation facilities, the control strategy has been embedded in FEM simulation as a programming routine. The simulations showed the efficiency of the proposed controller to suppress the microactuator's undesired vibrations