Nanoscale science department

Molecular mechanics Molecular mechanics consists of simulating the behavior of an object (e.g. a nanotube) by calculating the interaction of every atom with its neighbors. For example, this powerful technique enables us to calculate how tubes of different diameter are distorted when placed on a substrate. It costs the tubes energy to bend or deform, but in turn they can gain energy from the van der Waals interaction with other tubes or with the substrate they are deposited upon. The figure above shows the radial deformation of adsorbed single-wall carbon nanotubes calculated using molecular mechanics. The extent of radial deformation increases as the tube diameter is increased. The system can lower its energy by increasing the area of contact between the tube and the substrate. We have simulated the situation where two adsorbed nanotubes cross each other at a right angle. The bottom nanotube is compressed by the top tube which is strongly attracted to the substrate. From these calculations we can compute the force exerted on the lower tube, and understand how nanotubes deform. [Research home page] [ IBM home page | Order | Search | ContactIBM | Legal ]