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micro-electromechanical-system--mems
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Promising technology for electronic cooling: Nanofluidic micro pulsating heat pipes
, Article Journal of Electronic Packaging, Transactions of the ASME ; Volume 135, Issue 2 , 2013 ; 10437398 (ISSN) ; Mohammadi, M ; Shafii, M. B ; Shiee, Z ; Sharif University of Technology
2013
Abstract
Currently, the thermal management of microelectromechanical systems (MEMS) has become a challenge. In the present research, a micro pulsating heat pipe (MPHP) with a hydraulic diameter of 508 lm, is experimented. The thermal performance of the MPHP in both the transient and steady conditions, the effects of the working fluid (water, silver nanofluid, and ferrofluid), heating power (4, 8, 12, 16, 20, 24, and 28 W), charging ratio (20, 40, 60, and 80%), inclination angle (0 deg, 25 deg, 45 deg, 75 deg, and 90 deg relative to horizontal axis), and the application of magnetic field, are investigated and thoroughly discussed. The experimental results show that the optimum charging ratio for water...
Nonlinear analysis of pull-in voltage for a fully clamped microplate with movable base
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) ; Volume 10 , 2012 , Pages 71-75 ; 9780791845264 (ISBN) ; Moeenfard, H ; Ahmadian, M. T ; Sharif University of Technology
2012
Abstract
Micro-electro-mechanical systems (MEMS) such as sensors and actuators are rapidly gaining popularity in a variety of industrial applications. Usually these systems are constructed by a cantilever beam or plate along with a fixed substrate. The movable beam or plate deflects due to applied voltage between the plates. Pull-in voltage and contact time are the most important characteristic of these systems. Allowing the substrate to be movable in vertical direction pull-in voltage in comparison with the fixed substrate is expected to be much smaller. In this paper the pull-in voltage and the point at which pull-in takes place for a fully clamped microplate is evaluated. The nonlinear...
Design, simulation and fabrication of a MEMS accelerometer by using sequential and pulsed-mode DRIE processes
, Article Journal of Micromechanics and Microengineering ; Volume 27, Issue 1 , 2017 ; 09601317 (ISSN) ; Jafari, K ; Gharooni, M ; Sharif University of Technology
Institute of Physics Publishing
2017
Abstract
A sensitive half-bridge MEMS accelerometer fabricated by sequential and pulsed-mode processes is presented in this paper. The proposed accelerometer is analyzed by using conventional equations and the finite element method. The micromachining technology used in this work relies on two processes: sequential and pulsed-mode. In the sequential deep reactive ion etching process, a mixture of hydrogen and oxygen with a trace value of SF6 is used instead of polymeric material in the passivation step. The pulsed-mode process employs periodic hydrogen pulses in continuous fluorine plasma. Because of the continuous nature of this process, plus the in situ passivation caused by the hydrogen pulses,...
Nonlinear analysis of pull-in phenomenon and maximum deflection of MEMS with movable base under capillary and Van der Waals forces
, Article ASME International Mechanical Engineering ACongress and Exposition, Proceedings (IMECE), 9 November 2012 through 15 November 2012 ; Volume 9, Issue PARTS A AND B , November , 2012 , Pages 351-356 ; 9780791845257 (ISBN) ; Ahmadian, M. T ; Asemani, H ; Sharif University of Technology
2012
Abstract
In the analysis of micro structures, due to proximity of the elements Van der Waals forces plays an important role on the dynamics of the structure. In the modeling process a similar approach should be considered for the capillary effect caused by the moisture in the environment. Microplates and microbeams are used widely in the design and manufacturing of sensors and actuators. These structures are usually made of a cantilever beam or plate along with a fixed substrate. The cantilever beam usually deflects due to applied voltage. By increasing the voltage the pull-in phenomenon takes place. It is believed that the short contact time is one the important characteristic of any micro switches....
Sharif-Human movement instrumentation system (SHARIF-HMIS): Development and validation
, Article Medical Engineering and Physics ; Volume 61 , 2018 , Pages 87-94 ; 13504533 (ISSN) ; Akbari, A ; Zobeiri, O ; Rashedi, E ; Parnianpour, M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
The interest in wearable systems among the biomedical engineering and clinical community continues to escalate as technical refinements enhance their potential use for both indoor and outdoor applications. For example, an important wearable technology known as a microelectromechanical system (MEMS) is demonstrating promising applications in the area of biomedical engineering. Accordingly, this study was designed to investigate the Sharif-Human Movement Instrumentation System (SHARIF-HMIS), consisting of inertial measurement units (IMUs), stretchable clothing, and a data logger—all of which can be used outside the controlled environment of a laboratory, thus enhancing its overall utility....
Recent advancements in bulk metallic glasses and their applications: A review
, Article Critical Reviews in Solid State and Materials Sciences ; Volume 43, Issue 3 , 2018 , Pages 233-268 ; 10408436 (ISSN) ; Nemati, A ; Rahman, Z.U ; Shah, U. H ; Asgar, H ; Haider, W ; Sharif University of Technology
Taylor and Francis Inc
2018
Abstract
Bulk metallic glasses (BMGs), that display extraordinary properties of high strength, corrosion resistance, polymer-like formability, and excellent magnetic properties, are emerging as modern quintessential engineering materials. BMGs have garnered significant research enthusiasm owing to their tremendous technological and scientific standing. In this article, the recent advancements in the field of BMGs and their applications are put in a nutshell. Novel state-of-the-art production routes and nano/microimprinting strategies with salient features capable of circumventing the processing related complexities as well as accelerating modern developments, are briefly summarized. Heterogeneous BMG...
A combined experimental and numerical study of the effect of surface roughness on nanoindentation
, Article International Journal of Applied Mechanics ; Volume 11, Issue 7 , 2019 ; 17588251 (ISSN) ; Chamani, M ; Baghani, M ; Sharif University of Technology
World Scientific Publishing Co. Pte Ltd
2019
Abstract
Gold and copper thin films are widely used in microelectromechanical system (MEMS) and nanoelectromechanical system (NEMS) devices. Nanoindentation has been developed in mechanical characterization of thin films in recent years. Several researchers have examined the effect of surface roughness on nanoindentation results. It is proved that the surface roughness has great importance in nanoindentation of thin films. In this paper, the surface topography of thin films is simulated using the extracted data from the atomic force microscopy (AFM) images. Nanoindentation on a rough surface is simulated using a three-dimensional finite-element model. The results are compared with the results of...