Tags: multiscale models

Description

Nanotechnology sometimes involves mixing something very small into a larger, more conventional system. For example, mixing carbon nanotubes into a conventional polymer gives it added strength. Or, using a carbon nanotube as the channel between two larger, source-drain contacts creates a transistor with improved channel mobility. But simulating such systems becomes a huge challenge. The smaller parts of the system must be solved with great accuracy–for example, by simulating each atom within a carbon nanotube. But the same approach can't possibly be applied to the larger system–for example, to each atom in the thousands of polymer molecules in a realistic sample–or the whole problem would be too big to solve!

Multi-scale methods attempt to solve the problem by stitching together smaller domains (where atomistic models apply) and larger domains (where continuum models apply) into a coherent solution.

Learn more about multi-scale methods from the resources on this site, listed below.

Online Presentations (1-20 of 28)

  1. Atomistic Alloy Disorder in Nanostructures

    26 Feb 2007 | | Contributor(s):: Gerhard Klimeck

    Electronic structure and quantum transport simulations are typically performed in perfectly ordered semiconductor structures. Bands and modes are defined resulting in quantized conduction and discrete states. But what if the material is fundamentally disordered? What if the disorder is at the...

  2. Bandstructure in Nanoelectronics

    01 Nov 2005 | | Contributor(s):: Gerhard Klimeck

    This presentation will highlight, for nanoelectronic device examples, how the effective mass approximation breaks down and why the quantum mechanical nature of the atomically resolved material needs to be included in the device modeling. Atomistic bandstructure effects in resonant tunneling...

  3. BNC Annual Research Review: An Introduction to PRISM and MEMS Simulation

    04 Jun 2008 | | Contributor(s):: Jayathi Murthy

    This presentation is part of a collection of presentations describing the projects, people, and capabilities enhanced by research performed in the Birck Center, and a look at plans for the upcoming year.

  4. BNC Annual Research Symposium: Nanoscale Energy Conversion

    23 Apr 2007 | | Contributor(s):: Timothy S Fisher

    This presentation is part of a collection of presentations describing the projects, people, and capabilities enhanced by research performed in the Birck Center, and a look at plans for the upcoming year.

  5. Computer Simulation of Nanoparticles, Viruses, and Electrical Power-Generating Bacteria

    20 Mar 2007 |

    Models of cells and nanometer-scale biosystems are presented that clarify their physico-chemical characteristics and allow for computer- aided design of therapeutic and nanotechnical devices. Multiscale techniques are used to obtain rigorous, coarse-grained equations for the migration and...

  6. Engineering the Fiber-Matrix Interface in Carbon Nanotube Composites

    23 Mar 2006 | | Contributor(s):: Sharon Pregler, Yanhong Hu, Susan Sinnott

    Particle depositions on polymer and carbon substrates to induce surface chemical modification are a growing research topic in particle-surface interactions due to localized deposition energy and the high density of molecules impacting the surface. Previous simulations have shown that particle...

  7. First Principles-based Atomistic and Mesoscale Modeling of Materials

    01 Dec 2005 | | Contributor(s):: Alejandro Strachan

    This tutorial will describe some of the most powerful and widely used techniques for materials modeling including i) first principles quantum mechanics (QM), ii) large-scale molecular dynamics (MD) simulations and iii) mesoscale modeling, together with the strategies to bridge between them....

  8. First Principles-Based Modeling of materials: Towards Computational Materials Design

    20 Apr 2006 | | Contributor(s):: Alejandro Strachan

    Molecular dynamics (MD) simulations with accurate, first principles-based interatomic potentials is a powerful tool to uncover and characterize the molecular-level mechanisms that govern the chemical, mechanical and optical properties of materials. Such fundamental understanding is critical to...

  9. Hierarchical Physical Models for Analysis of Electrostatic Nanoelectromechanical Systems (NEMS)

    05 Jan 2006 | | Contributor(s):: Narayan Aluru

    This talk will introduce hierarchical physical models and efficient computational techniques for coupled analysis of electrical, mechanical and van der Waals energy domains encountered in Nanoelectromechanical Systems (NEMS). Numerical results will be presented for several silicon...

  10. HPC and Visualization for multimillion atom simulations

    21 Jun 2005 | | Contributor(s):: Gerhard Klimeck

    This presentation gives an overview of the HPC and visulaization efforts involving multi-million atom simulations for the June 2005 NSF site visit to the Network for Computational Nanotechnology.

  11. Ionic Selectivity in Channels: complex biology created by the balance of simple physics

    05 Jun 2008 | | Contributor(s):: Bob Eisenberg

    An important class of biological molecules—proteins called ionic channels—conduct ions (like Na+ , K+ , Ca2+ , and Cl− ) through a narrow tunnel of fixed charge (‘doping’). Ionic channels control the movement of electric charge and current across biological membranes and so play a role in...

  12. Irradiation and Nanomechanics of Multi-Walled Carbon Nanotubes

    23 Mar 2006 | | Contributor(s):: Sharon Pregler, Susan Sinnott

    Irradiation of nanotube structures with electron and ion beams has been used to produce functionalized nanotubes and fundamentally new structures, including junctions. Here, we build on previous studies to investigate the low-energy electron and ion (Ar and CF3) beam irradiation of triple walled...

  13. Microscale Ionic Wind for Local Cooling Enhancement

    26 Oct 2007 | | Contributor(s):: David B Go

    As the electronics industry continues to develop small, highly functional, mobile devices, new methods of cooling are required to manage the thermal requirements of the not only the chip but the entire system. Comfortable skin temperatures, small form factors, and limited power consumption are...

  14. Modeling and Simulation of Sub-Micron Thermal Transport

    26 Sep 2005 | | Contributor(s):: Jayathi Murthy

    In recent years, there has been increasing interest in understanding thermal phenomena at the sub-micron scale. Applications include the thermal performance of microelectronic devices, thermo-electric energy conversion, ultra-fast laser machining and many others. It is now accepted that...

  15. Molecular Transport Structures: Elastic Scattering, Vibronic Effects and Beyond

    13 Feb 2006 | | Contributor(s):: Mark Ratner, Abraham Nitzan,

    Current experimental efforts are clarifying quite beautifully the nature of charge transport in so-called molecular junctions, in which a single molecule provides the channel for current flow between two electrodes. The theoretical modeling of such structures is challenging, because of the...

  16. Multiscale Modeling of the Mechanical Behavior of Polymer-Based Nanocomposites

    25 Mar 2004 |

    Polymers filled with nanoscale fillers (carbon nanotubes or nanoparticles) exhibit enhanced properties compared with the neat polymer and with the polymer filled with micron-sized fillers at same volume fraction. Most interestingly, combinations of exceptional properties may be obtained as, for...

  17. Nano-Scale Device Simulations Using PROPHET

    20 Jan 2006 | | Contributor(s):: yang liu,

    These two lectures are aimed to give a practical guide to the use of ageneral device simulator (PROPHET) available on nanoHUB. PROPHETis a partial differential equation (PDE) solver that offers usersthe flexibility of integrating new models and equations for theirnano-device simulations. The...

  18. Nano-Scale Device Simulations Using PROPHET-Part I: Basics

    20 Jan 2006 | | Contributor(s):: yang liu,

    Part I covers the basics of PROPHET,including the set-up of simulation structures and parameters based onpre-defined PDE systems.

  19. Nano-Scale Device Simulations Using PROPHET-Part II: PDE Systems

    20 Jan 2006 | | Contributor(s):: yang liu,

    Part II uses examples toillustrate how to build user-defined PDE systems in PROPHET.

  20. Numerical Aspects of NEGF: The Recursive Green Function Algorithm

    14 Jun 2004 | | Contributor(s):: Gerhard Klimeck

    Numerical Aspects of NEGF: The Recursive Green Function Algorithm