NON-EQUILIBRIUM MOLECULAR DYNAMICS APPROACH FOR NANO-ELECTRO-MECHANICAL SYSTEMS: NANO-FLUIDICS AND ITS APPLICATIONS

摘要

A three-dimensional non-equilibrium molecular dynamics code has been developed and evaluated to provide fundamental understandings of nano-fluidics at molecular level. Intermolecular energy and force between fluid-fluid and fluid-wall particles were all included. Molecular dynamics results were verified by simulating both homogeneous and heterogeneous flows in a nano-tube and then compared with the classical Navier-Stokes solution with non-slip wall boundary conditions. At equilibration state, the macroscopic parameters were calculated using the statistical calculation. Liquid argon fluids within platinum walls were simulated for a homogeneous system. Also positively charged particles are mixed with water-like solvent particles to investigate the non-Newtonian behavior of the heterogeneous fluid. For an electrowetting phenomenon, a positive charged droplet moving on the negative charged ultra thin film was successfully simulated and compared with a macroscopic experiment. Nano-jetting mechanism was identified by simulating droplet ejection, breakup, wetting, and drying process in a consequent manner. In addition, conceptual nano/micropumps using electrowetting phenomenon are simulated. The present molecular dynamics approach showed its promising capability for the wide range of NEMS/MEMS applications.