Coarse-Grained Molecular Dynamics for Nano-Design
Robert E. Rudd
Lawrence Livermore National Laboratory, US
Keywords: concurrent multiscale simulation, molecular dynamics, finite element modeling, coarse-grained molecular dynamics
The design of nanoscale mechanical systems poses a novel
set of challenges for modeling and simulation.
The need for an accurate model of the nanoscale components is clear.
This can be of the form of an engineering model, such as a
finite element model (FEM), suitably parameterized for the nanoscale;
alternatively, nanoscale components may be treated in a bottom-up
approach in which the material is modeled at the atomic level.
We discuss this latter, atomistic type of modeling.
The device is not completely isolated from its environment, however.
It is typically bound to a substrate and may interact with fluid
surroundings. The relative importance of these interfaces
scales like the surface area to volume ratio and becomes more
important as the system size is reduced. For system design,
it is important to model both the nanoscale components of
the device and their surroundings, a problem that is inherently
multiscale, and one in which the scales interact strongly.
Concurrent multiscale simulation provides a solution to this
problem. An atomistic methodology is coupled to a more
coarse-grained model, such as FEM, in a single simulation.
This provides precision where it is needed, while
retaining the efficiency needed to simulate the entire
NSTI Nanotech 2003 Conference Technical Program Abstract