Prediction Of Elastic Properties Of Micro- And Nano-Scale Thin Films

Bibliographic Details
Main Author: Kim, Han Sung
Language:English
Published: The Ohio State University / OhioLINK 2008
Subjects:
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=osu1211905997
id ndltd-OhioLink-oai-etd.ohiolink.edu-osu1211905997
record_format oai_dc
spelling ndltd-OhioLink-oai-etd.ohiolink.edu-osu12119059972021-08-03T05:53:49Z Prediction Of Elastic Properties Of Micro- And Nano-Scale Thin Films Kim, Han Sung Mechanical Engineering <p>Simulation algorithms are developed for the prediction of effective elastic properties of NEMS (Nano-Electro Mechanical Systems) and MEMS (Micro-Electro Mechanical Systems) thin films. Finite Element Method (FEM) is used for micro-scale simulation while ab-initio Molecular Dynamics (MD) is employed for nano-scale. </p><p>A lattice model is utilized in order to simulate microstructures of thin films. The proposed method can generate a statistically equivalent microstructure to any single phase micrograph in terms of the number of grains and the grain size distribution. A desired grain size distribution (GSD) is achieved by manipulating nucleation process. Analytical functions for GSD are obtained by taking into account of the domain size and the number of grains. It is believed that nucleation and growth can be controlled by temperature and pressure. The influence of temperature and pressure on the grain size as well as the grain size distribution is investigated.</p><p>A quasi-3D mesh of the thin film is generated by employing prism elements. By applying specific boundary conditions to the quasi-3D meshed microstructure, the elastic properties of MEMS thin films are obtained through FEM analysis. </p><p>The simulation results show that stochastic distributions of grain anisotropy have a significant influence on overall elastic properties at micro-scale. A fundamental statistical methodology is adopted to characterize elastic properties of thin films.</p><p>For nano-scale simulations, the bulk modulus (and other elastic properties) can be influenced by grain boundary when grain boundary volume fraction is not negligible. Consequently, it is desirable to determine the size limit when the grain boundary begins to influence the bulk modulus significantly. The developed MD simulation algorithm found that 6nm is the critical grain size for polysilicon. Moreover, equations are derived from the simulation results for estimating bulk modulus by considering both grain and grain boundary. The developed MD simulation technique can be used to characterize bulk modulus of NEMS materials and to determine the size limit above which grain boundary can be ignored in bulk modulus simulation.</p> 2008-10-15 English text The Ohio State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=osu1211905997 http://rave.ohiolink.edu/etdc/view?acc_num=osu1211905997 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Mechanical Engineering
spellingShingle Mechanical Engineering
Kim, Han Sung
Prediction Of Elastic Properties Of Micro- And Nano-Scale Thin Films
author Kim, Han Sung
author_facet Kim, Han Sung
author_sort Kim, Han Sung
title Prediction Of Elastic Properties Of Micro- And Nano-Scale Thin Films
title_short Prediction Of Elastic Properties Of Micro- And Nano-Scale Thin Films
title_full Prediction Of Elastic Properties Of Micro- And Nano-Scale Thin Films
title_fullStr Prediction Of Elastic Properties Of Micro- And Nano-Scale Thin Films
title_full_unstemmed Prediction Of Elastic Properties Of Micro- And Nano-Scale Thin Films
title_sort prediction of elastic properties of micro- and nano-scale thin films
publisher The Ohio State University / OhioLINK
publishDate 2008
url http://rave.ohiolink.edu/etdc/view?acc_num=osu1211905997
work_keys_str_mv AT kimhansung predictionofelasticpropertiesofmicroandnanoscalethinfilms
_version_ 1719427347642318848