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Dynamic modeling and sensitivity analysis of atomic force microscope pushing force in nanoparticle manipulation on a rough substrate [electronic resource]
, Article Journal of Advanced Science, Engineering and Medicine ; 2013, Vol. 5, pp. 1-10 ; Mahboobi, Seyed Hanif ; Meghdari, Ali ; Sharif University of Technology
Abstract
An Atomic Force Microscope (AFM) is a capable tool to manipulate nanoparticles by exerting pushing force on the nanoparticles located on the substrate. In reality, the substrate cannot be considered as a smooth surface particularly at the nanoscale. Hence, the particle may encounter a step on the substrate during a manipulation. In this study, dynamics of the nanoparticle on a stepped substrate and critical pushing force in the manipulation are investigated. There are two possible dynamic modes that may happen in the manipulation on the stepped substrate. In one mode, the nanoparticle may slide on the step edge and then climb up to the step which is a desired mode. Another possible mode is...
Molecular dynamics simulation of manipulation of metallic nanoclusters on double-layer substrates [electronic resource]
, Article Physica E: Low-dimensional Systems and Nanostructures ; 2010, Vol. 42, No. 9, pp. 2364-2374 ; Meghdari, Ali ; Jalili, Nader ; Amiri, Farshid ; Sharif University of Technology
Abstract
Molecular dynamics simulations are carried out to investigate the manipulation of metallic clusters on double-layer surfaces. The system parts are made of transition metals. The conditions which are subjected to change in the tests are material combinations for cluster, main substrate and lubricant layer (adlayer). In addition to qualitative observations, two criteria which represent the particle deformation and substrate abrasion are utilized as evaluation tools and are computed for each case. Obtaining this sort of knowledge is highly beneficial for further experiments in order to be able to plan the conditions and routines, which guarantee better success in the manipulation process
Developing a Molecular Dynamics Simulation Software for Modeling of Nano-Contact Processes (CEDRA Molecular Dynamics Software )
,
M.Sc. Thesis
Sharif University of Technology
;
Meghdari, Ali
(Supervisor)
;
Mahboobi, Hanif
(Supervisor)
Abstract
Molecular Dynamics as a powerful method in the field of Nano-simulation has been widely used in recent years. Different contact processes such as Nano-manipulation, AFM Imaging, and Nano-indentation can be simulated using this method. There have been numerous researches done on calculating techniques of simulation of different phenomena in Nano-technology. Specifically, friction and Nano-indentation which are parts of Nano-contact processes have been simulated by different investigators. However, on some other parts, e.g. Nano-manipulation and AFM Imaging, there are few studies done up to now. Thus, a simulation and computational software seems necessary in this field. The main goal of...
Robust adaptive backstepping control of uncertain lorenz system [electronic resource]
, Article Journal of American Institute of Physics ; 2010, Vol. 20, pp. 1-5 ; Jalili, Nader ; Mahboobi, Seyed Hanif ; Alasty, Aria ; Meghdari, Ali ; Sharif University of Technology
Abstract
In this paper, a novel robust adaptive control method is proposed for controlling the Lorenz chaotic attractor. A new backstepping controller for the Lorenz system based on the Lyapunov stability theorem is proposed to overcome the singularity problem that appeared in using the typical backstepping control method. By exploiting the property of the system, the resulting controller is shown to be singularity free and the closed loop system is globally stable. Due to unavailability of system states measurement in practice, the controller is selected such that only one system state is needed. To overcome the problem of parameter uncertainty, an additional term to Lyapunov function is added and...
Molecular Dynamics Simulation of Nanoscale Effects in Nanomanipulation
, Ph.D. Dissertation Sharif University of Technology ; Meghdari, Ali (Supervisor)
Abstract
Metallic clusters are among the best candidates that may be utilized as building blocks for constructing nanostructures. Despite their great potential, a variety of questions arises about their suitability as building blocks at the nanoscale level. One of the key factors in the assembly of nanoclusters is the precise positioning that is required by a manipulation system. The response of clusters, which are subjected to this process, is of great importance. Currently, the size of clusters used as building blocks is shrinking down to a few nanometers. In such cases, the particle nature of matter plays an important role in manipulator/cluster/substrate interactions. Having a deeper insight into...
Molecular dynamics study of success evaluation for metallic nanoparticles manipulation on gold substrate
, Article Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference 2009, DETC2009, 30 August 2009 through 2 September 2009 ; Volume 6 , August–September , 2010 , Pages 345-346 ; 9780791849033 (ISBN) ; Meghdari, A ; Jalili, N ; Sharif University of Technology
2010
Abstract
Using molecular dynamics, the behavior of nanoparticles during manipulation process is investigated in this paper. The system consists of a tip, cluster and substrate. The focus of the present research is on ultra-fine metallic nanoclusters. The system of concern is made of different transition metals. Two criteria have been proposed for evaluation of success in a pushing process. Such criteria describe the intactness of nanoparticle/substrate pair. The effects of cluster material and manipulation speed on the success of the process are investigated by atomistic simulations. Such qualitative simulation studies can evaluate the level of success of manipulation regarding different working...
Molecular dynamics study of success evaluation for metallic nanoparticles manipulation on gold substrate
, Article Proceedings of the ASME Design Engineering Technical Conference, 30 August 2009 through 2 September 2009, San Diego, CA ; Volume 6 , 2009 , Pages 345-346 ; 9780791849033 (ISBN) ; Meghdari, A ; Jalili, N ; Sharif University of Technology
2009
Abstract
Using molecular dynamics, the behavior of nanoparticles during manipulation process is investigated in this paper. The system consists of a tip, cluster and substrate. The focus of the present research is on ultra-fine metallic nanoclusters. The system of concern is made of different transition metals. Two criteria have been proposed for evaluation of success in a pushing process. Such criteria describe the intactness of nanoparticle/substrate pair. The effects of cluster material and manipulation speed on the success of the process are investigated by atomistic simulations. Such qualitative simulation studies can evaluate the level of success of manipulation regarding different working...
First-principle Study of Pressure Effects on the Structural and Magnetic Phase Transitions and the Electronic Structure of AeFe2As2(Ae=Ba,Sr,Ca) Compounds
,
Ph.D. Dissertation
Sharif University of Technology
;
Akhavan, Mohammad
(Supervisor)
;
Hadipour, Hanif
(Co-Supervisor)
Abstract
The ternary 122-type AeFe2As2 (Ae=Ba,Sr,Ca) compounds are antiferromagnetic metals with the orthorhombic lattice structure at ambient pressure and low temperature. By applying mechanical pressure, structural, magnetic and superconducting transitions occur in these compounds. The isovalent doping of Ba with Sr and Ca elements induces chemical pressure and reduces the onset pressure of these transitions. The main purpose of this thesis is to investigate and compare the effects of mechanical and chemical pressures on the structural and magnetic phase transition in the 122 compounds. To achieve this purpose, we have done first-principle calculations for many properties such as the structural...
Qualitative study of nanocluster positioning process: 2D molecular dynamics simulations
, 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 1161-1170 ; 9780791848746 (ISBN) ; Meghdari, A ; Jalili, N ; Amiri, F ; Sharif University of Technology
2009
Abstract
One of the key factors in the assembly of nanoclusters is the precise positioning of them by a manipulation system. Currently the size of clusters used as building blocks is shrinking down to a few nanometers. In such cases, the particle nature of matter plays an important role in the manipulator/cluster/substrate interactions. Having a deeper insight to the aforementioned nanoscale interactions is crucial for prediction and understanding of the behavior of nanoclusters during the positioning process. In the present research, 2D molecular dynamics simulations have been used to investigate such behaviors. Performing planar simulations can provide a fairly acceptable qualitative tool for our...
Molecular dynamics study of bio-manipulation in aqueous media
, Article Micro and Nano Letters ; Volume 11, Issue 1 , 2016 , Pages 9-14 ; 17500443 (ISSN) ; Pishkenari, H. N ; Mahboobi, S. H ; Sharif University of Technology
Institution of Engineering and Technology
2016
Abstract
Nano-manipulation is one of the most important aspects of nano-robotics and nano-assembly. The positioning process is considered by many researches to be one of the most important parts of nano-assembly, but has been poorly investigated, particularly for biologic samples. This Letter is devoted to modelling the process of positioning a biomolecule with atomic force microscopy (AFM) in an aqueous media using molecular dynamics simulations. Carbon nanotube (CNT) and graphite sheet are selected as AFM tip and substrate, respectively. To consider the effects of the medium on the manipulation, several models for decreasing the calculations including implicit, coarse grained, and all-atom methods...
Adaptive regulation and set-point tracking of the Lorenz attractor
, Article Chaos, Solitons and Fractals ; Volume 32, Issue 2 , 2007 , Pages 832-846 ; 09600779 (ISSN) ; Shahrokhi, M ; Mahboobi, S. H ; Sharif University of Technology
2007
Abstract
In this paper, an approach is proposed for controlling the uncertain Lorenz system. Based on an identification technique, a controller is designed that guarantees the regulation of all states in the presence of system uncertainty. Since in some applications the challenging problem of output tracking is desired, we have proposed several effective set-point tracking control techniques. The control schemes that are based on the feedback linearization method, can stabilize the internal dynamics of the system. Simulation results have illustrated the effectiveness of the proposed schemes. © 2005 Elsevier Ltd. All rights reserved
Observer-based control design for three well-known chaotic systems
, Article Chaos, Solitons and Fractals ; Volume 29, Issue 2 , 2006 , Pages 381-392 ; 09600779 (ISSN) ; Shahrokhi, M ; Pishkenari, H. N ; Sharif University of Technology
2006
Abstract
In this paper, a singularity-free approach is proposed for controlling three well-known chaotic systems namely Lorenz, Chen and Lu. The control design guarantees the regulation of two states and boundedness of the remaining state. The stability of the proposed scheme has been shown using the Lyapunov stability theorem. Implementation of the proposed control technique requires system states, while in most of practical applications only the system output is available. To overcome this problem, a nonlinear observer is coupled with the controller. Simulation results have illustrated the effectiveness and robustness of the proposed schemes. If the control action is applied to the second system...
Molecular dynamics simulation of manipulation of metallic nanoclusters on stepped surfaces
, Article Central European Journal of Physics ; Volume 9, Issue 2 , 2011 , Pages 454-465 ; 18951082 (ISSN) ; Meghdari, A ; Jalili, N ; Amiri, F ; Sharif University of Technology
2011
Abstract
Molecular dynamics simulations are carried out to investigate the manipulation of metallic clusters on stepped surfaces. Five surface forms are considered in the simulations. The system parts are made of pure transition metals and Sutton-Chen many-body potential is used as interatomic potential. The conditions which are subjected to change in the tests include: materials used for particles and substrate, and surface step conditions. In addition to qualitative observations, two criteria which represent the particle deformation and substrate abrasion are utilized as evaluation tools and are computed for each case. Simulation results show the effect of the aforementioned working conditions on...
Planar molecular dynamics simulation of Au clusters in pushing process
, Article International Journal of Nanomanufacturing ; Volume 5, Issue 3-4 , 2010 , Pages 288-296 ; 17469392 (ISSN) ; Meghdari, A ; Jalili, N ; Amiri, F ; Sharif University of Technology
2010
Abstract
Based on the fact that the manipulation of fine nanoclusters calls for more precise modelling, the aim of this paper is to conduct an atomistic investigation for interaction analysis of particle-substrate system for pushing and positioning purposes. In the present research, 2D molecular dynamics simulations have been used to investigate such behaviours. Performing the planar simulations can provide a fairly acceptable qualitative tool for our purpose while the computation time is reduced extremely in comparison to 3D simulations. To perform this study, Nose-Hoover dynamics and Sutton-Chen interatomic potential will be used to investigate the behaviour of the aforementioned system. Pushing of...
Molecular dynamics simulation of manipulation of metallic nanoclusters on double-layer substrates
, Article Physica E: Low-Dimensional Systems and Nanostructures ; Volume 42, Issue 9 , 2010 , Pages 2364-2374 ; 13869477 (ISSN) ; Meghdari, A ; Jalili, N ; Amiri, F ; Sharif University of Technology
2010
Abstract
Molecular dynamics simulations are carried out to investigate the manipulation of metallic clusters on double-layer surfaces. The system parts are made of transition metals. The conditions which are subjected to change in the tests are material combinations for cluster, main substrate and lubricant layer (adlayer). In addition to qualitative observations, two criteria which represent the particle deformation and substrate abrasion are utilized as evaluation tools and are computed for each case. Obtaining this sort of knowledge is highly beneficial for further experiments in order to be able to plan the conditions and routines, which guarantee better success in the manipulation process
Qualitative study of nanoassembly process: 2-D molecular dynamics simulations
, Article Scientia Iranica ; Volume 17, Issue 1 F , 2010 , Pages 1-11 ; 10263098 (ISSN) ; Meghdari, A ; Jalili, N ; Amiri, F ; Sharif University of Technology
2010
Abstract
Precise positioning of nanoclusters through manipulation in the presence of other clusters is one of the main challenging tasks in nanoclusters assembly. Currently, the size of clusters which are used as building blocks is decreasing to a few nanometers. As a result, the particle nature of the matter has a crucial role in manipulator/cluster/substrate interactions. In order to understand and predict the behavior of nanoclusters during the positioning process, it is, therefore, essential to have a deep insight into the aforementioned nanoscale interactions, in this research, 2-D molecular dynamics simulations are used to investigate such behaviors. Performing the planar simulations can...
Molecular dynamics study of 'success evaluation' for metallic nanoparticles manipulation on gold substrate
, Article Micro and Nano Letters ; Volume 5, Issue 5 , 2010 , Pages 286-290 ; 17500443 (ISSN) ; Meghdari, A ; Jalili, N ; Amiri, F ; Sharif University of Technology
2010
Abstract
One of the key factors in the assembly of nanoparticles and controlled construction of such systems is their positioning by a manipulation system. The response of clusters that are subjected to this process is of great importance. In this study, the behaviour of metallic nanoparticles during the manipulation process on an Au substrate is investigated using molecular dynamics. Two criteria are proposed for the evaluation of success in a pushing process regarding the intactness of a nanoparticle/substrate pair. The effects of cluster material, temperature and manipulation speed on the success of the process are investigated based on the simulation results
Two-dimensional atomistic simulation of metallic nanoparticles pushing
, Article Modern Physics Letters B ; Volume 23, Issue 22 , 2009 , Pages 2695-2702 ; 02179849 (ISSN) ; Meghdari, A ; Jalili, N ; Amiri, F ; Sharif University of Technology
2009
Abstract
Nanomanipulation as a new emerging area enables precise manipulation, interaction and control at the nanoscale. Currently, the modeling schemes are based on continuum mechanics approaches. A main consideration in the nanomanipulation process is the fact that surface attraction forces are greater than gravitational forces at the nanoscale. In other words, surface area properties dominate volume properties. Especially at the nanoscale (i.e. the manipulation of fine nanoparticles with size of about 5 nm) the physical phenomena have not been completely understood. Along this line of reasoning, the aim of this paper is to conduct an atomistic investigation of physical interaction analysis of...
Planar molecular dynamics simulation of metallic nanoparticles manipulation
, Article 2008 8th IEEE Conference on Nanotechnology, IEEE-NANO, Arlington, TX, 18 August 2008 through 21 August 2008 ; 2008 , Pages 163-164 ; 9781424421046 (ISBN) ; Meghdari, A ; Jalili, N ; Amiri, F ; Sharif University of Technology
2008
Abstract
The aim of this research is to conduct atomistic investigations of physical interaction analysis of nanoscale objects manipulation. The system consists of tip, particle and substrate. The manipulation tool moves with a constant speed while pushing the particle in a desired direction. The focus of the research is on ultra-fine metallic nanoparticles. To perform this research, Nose-Hoover dynamics and Sutton-Chen interatomic potential will be used to investigate the behavior of the aforementioned system which is made from different transition metals. The effects of size, material type and temperature on the success of the process have been investigated by planar molecular dynamics. © 2008 IEEE...
Closed-loop finite element modeling for analysis of smart structures in ansys environment
, Article 2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006, Chicago, IL, 5 November 2006 through 10 November 2006 ; 2006 ; 10716947 (ISSN); 0791837904 (ISBN); 9780791837900 (ISBN) ; Shahidi, A ; Abedian, A ; Meghdari, A ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2006
Abstract
It would be promising if one can simulate the closed-loop behavior of a smart system in an available FEM software such as "ANSYS". The ANSYS/Multiphysics software has the ability of coupling different physical domains and also modeling smart materials such as piezoelectric and piezoresistives, i.e. it has the capability of modeling smart structures. The dynamic modeling of the controlled structures is then realized by the ANSYS programming tool. This aspect highly facilitates the overall system behavior analysis and at the same time various control methods can be tested without noticing the time consuming structural analysis involved. In this research work, it is tried the mentioned idea to...