Multiscale particle dynamics in nanoimprint process

A multiscale particle method for coupling continuum and molecular models is described. In this method, the continuum model was assumed to be a lattice form and can be applied in non-characteristic areas or far-away regions from the large deformations to save computational time. Defining a series of critical energies for different lattice sizes is convenient for lattice refinement. In the thermal equilibrium case, the efficiency is around six times higher than that of a classical molecular dynamics (MD) simulation; in addition, great numerical precision is achieved. To test the connection at the molecular/continuum interface, a large-deformation case was studied in a nanoimprinting process. The results were compared with the MD simulation and it was found that the deviation could be reduced through a moderate adjustment of the critical energy in the lattices. This is good evidence that this method is a seamless treatment technology. PACS 02.70.Ns; 81.07.Lk; 81.16.Rf; 81.16.Nd; 62.25.-g