DOCKING ENVELOPES FOR THE ASSEMBLY OF MOLECULAR BEARINGS

To design a process for the assembly or self-assembly of a nanomachine requires knowing the degree of spatial control needed to put the comp onents together. A useful starting point in this area of study is the concept of a docking envelope, which is a continuous region of initial condition parameter space for which two structures will dock. In this paper docking envelopes, determined from molecular dynamics simulatio n, are presented for the assembly of a molecular bearing consisting of two concentric carbon nanotubes. in-the beginning of each simulation the outer nanotube (sleeve) is held in place and the inner nanotube (s haft) starts far away from, but is given an initial velocity toward, t he sleeve. The docking envelope in this case is delineated by the init ial offset from a coaxial geometry. In order to address recent concern s about the effects of zero-point energy leakage and chaos in classica l simulations of nanomachine components, docking envelopes from two ty pes of simulations are presented: fully atomistic (all degrees of free dom included) and rigid body (each nanotube rigid but shaft allowed to rotate and translate).