Browsing by Author "Promyoo, Rapeepan"

Now showing 1 - 6 of 6
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    AFM-Based Fabrication of Nanofluidic Device for Medical Application
    (Office of the Vice Chancellor for Research, 2014-04-11) Promyoo, Rapeepan; El-Mounayri, Hazim; Karingula, Varun Kumar
    Recent developments in science and engineering have advanced the atomic manufacture of nanoscale structures, allowing for improved high-performance technologies. Among them, AFM-based nanomachining is considered a potential manufacturing tool for operations including machining, patterning, and assembling with in situ metrology and visualization. In this work, atomic force microscope (AFM) is employed in the fabrication of nanofluidic device for DNA stretching application. Nanofluidic channels with various depths and widths are fabricated using AFM indentation and scratching techniques. To introduce the fluid inside the nanochannels, microchannels are made on both sides of the nanochannels. Photolithography technique is used to fabricate microfluidic channels on silicon wafers. A 3D Molecular Dynamics (MD) model is used to guide the design and fabrication of nanodevices through nanoscratching. The correlation between the scratching conditions, including applied force, scratching depth, and distant between any two scratched grooves and the defect mechanism in the substrate/workpiece is investigated. The MD model allows proper process parameter identification resulting in more accurate nanochannel size.
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    AFM-Based Nanofabrication: Modeling, Simulation, and Experimental Verification
    (Office of the Vice Chancellor for Research, 2013-04-05) Promyoo, Rapeepan; El-Mounayri, Hazim; Karingula, Varun Kumar; Varahramyan, Kody
    Recent developments in science and engineering have advanced the fabrication techniques for micro/ nanodevices. Among them, atomic force microscope (AFM) has already been used for nanomachining and fabrication of micro/nanodevices. In this paper, a computational model for AFM-based nanofabrication processes is being developed. Molecular Dynamics (MD) technique is used to model and simulate mechanical indentation and scratching at the nanoscale. The effects of AFM-tip radius and crystal orientation are investigated. The simulation is also used to study the effect of the AFM tip speed on the indentation force at the interface between the tip and the substrate/workpiece. The material deformation and indentation geometry are extracted from the final locations of atoms, which are displaced by the rigid indenter. Material properties including modulus of elasticity and hardness are estimated. It is found that properties vary significantly at the nanoscale. AFM is used to conduct actual nanoindentation and scratching, to validate the MD simulation. Qualitative agreement is found. Finally, AFM-based fabrication of nanochannels/nanofluidic devices is conducted using different applied forces, scratching length, and feed rate.
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    AFM-Based Nanofabrication: Modeling, Simulation, and Experimental Verification
    (Office of the Vice Chancellor for Research, 2012-04-13) Promyoo, Rapeepan; El-Mounayri, Hazim; Varahramyan, Kody
    Recent developments in science and engineering have advanced the fabrication techniques for micro/nanodevices. Among them, atomic force microscope (AFM) has already been used for nanomachining and fabrication of micro/nanodevices. In this research, a multi-scale computational model for AFM-based nanofabrication processes is being developed. Molecular Dynamics (MD) technique was used to model and simulate mechanical indentation and scratching at the nanoscale. MD simulation represents itself as a viable alternative to the expensive traditional experimental approach, which can be used to study the effects of various indentation variables in a much more cost effective way. The effects of workpiece materials, AFM-tip materials, AFM-tip radius, as well as crystal ori entations were investigated. The simulation allows for prediction of the indentation forces at the interface between an indenter and a workpiece. Also, the MD simulation was used to study the effects of speed on the indentation force. The material deformation and indentation geometry are extracted based on the final locations of atoms, which are displaced by the rigid indenter. Material properties including modulus of elasticity and friction coefficient are presented. AFM was used to conduct actual indentation and scratching at the nanoscale, and provide measurements to validate the predictions from the MD simulation. Qualitative agreement was found between the simulation and actual AFM-based nanomachining.
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    Experimental Study of Material Removal at Nanoscale
    (Elsevier, 2018-01-01) Promyoo, Rapeepan; El-Mounayri, Hazim; Agarwal, Mangilal; Mechanical Engineering, School of Engineering and Technology
    In order to develop nano-machining into a viable and efficient process, there is a need to achieve a better understand the relation between process parameters (such as feed, speed, and depth of cut) and resulting geometry. In this study, a comprehensive experimental parametric study was conducted to produce a database that is used to select proper machining conditions for guiding the fabrication of precise nano-geometries. The parametric studies conducted using AFM nanosize tips showed the following: normal forces for both nano-indentation and nano-scratching increase as the depth of cut increases. The indentation depth increases with tip speed, but the depth of scratch decrease with increasing tip speed. The width and depth of scratched groove also depend on the scratch angle. The recommended scratch angle is at 90°. The surface roughness increases with step over, especially when the step over is larger than the tip radius. The depth of cut also increases as the step over decreases.
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    Innovative Digital Manufacturing Curriculum for Industry 4.0
    (Elsevier, 2019) Promyoo, Rapeepan; Alai, Shashank; El-Mounayri, Hazim; Mechanical and Energy Engineering, School of Engineering and Technology
    Manufacturing companies across all major industries are facing serious challenges trying to competitively design and manage modern products, which are becoming increasingly complex multi-domain systems or “systems of systems”. Model-based systems driven product development (or SDPD, for Systems Driven Product Development) has been proposed as a solution based on driving the product lifecycle from the systems requirements and tracing back performance to stakeholders’ needs through a RFLP (Requirement, Functional, Logical, Physical) traceability process. The SDPD framework integrates system behavioral modeling with downstream product design and manufacturing process practices to support the verification/validation of the systems behavior as products progress through all phases of the lifecycle, as well as the optimization of trade-offs decisions by maintaining the cross-product digital twin and thread for global decision optimization in an efficient and effective way. We have developed an innovative digital manufacturing curriculum (designed around the SDPD paradigm) that is based on the digitalization of the SE (Systems Engineering) process through the integration of modelling and simulation continuum, in the form of Model-based Systems Engineering (MBSE), with Product lifecycle management (PLM). At the core of this curriculum is a shift of focus from theory to implementation and practice, through an applied synthesis of engineering fundamentals and systems engineering, that is driven by a state-of-the-art digital innovation platform for product (or system) development consisting of integrated software (digital) tools spanning the complete lifecycle. The curriculum consists of three key components, namely, modelling and simulation continuum, traceability, and digital thread. The curriculum provides a foundation for implementing the digital twin and supports the training of the next generation of engineers for Industry 4.0. The digital manufacturing (or SDPD) framework is applied in the design and optimization of an electric skateboard. The implementation demonstrates: 1) The benefits of digitalization/model-based engineering when developing complex multi-domain products or systems; 2) The ability of students to effectively complete a real-life modern product development within the time line of one semester; 3) The provision of MBSE curriculum for Engineering Education 4.0, characterized by key, integrated skills for the digital enterprise and Industry 4.0.
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    Integrated System Model of District Cooling for Energy Consumption Optimization
    (ECOS, 2020-11) Dalvi, Akshay S.; Razban, Ali; El-Mounayri, Hazim; El-Mekkawy, Tarek; Promyoo, Rapeepan; Mechanical and Energy Engineering, School of Engineering and Technology
    The successful modeling of a multi-plant district cooling (DC) system presents several challenges in integrating system level requirements with engineering analysis for verification and optimization. Currently, the ability to predict the behavior and performance parameters such as chilled water temperature difference, annual energy consumption, and central chiller plant coefficient of performance (COP) of the dynamic system is limited. Effective modeling and efficient simulation are required when it comes to complex physical systems. This paper presents an integrated model that combines system architecture with physical modeling to represent and simulate a multi-plant district cooling system (DCS). We refer to this model as model-based systems engineering (MBSE) model of the DC system. A systems modeling language (SysML) model is created to develop a multi-domain architecture of the DC system that will satisfy stakeholder needs and requirements. This model is capable of executing behavior and parametric aspects (or “views”) of the system. A closed-loop of information flow was developed to map SysML constructs with their respective Modelica models to support the integration of simulated experiments with SysML construct. The integrated MBSE model is successfully implemented and the results show that the IPLV.SI value of the chiller model was 6.4157, which is in the acceptable range. Based on the initial conditions provided by the actual plant, the simulation results show that the chilled water temperature predictions by Modelica as 4.8℃ verify the corresponding stakeholders’ requirements captured in the SysML model.