Stability and analysis of configuration-tunable bi-directional MWNT bearings.

We report on the energetic and structural stability of configuration-tunable, bi-directional linear bearings based on cap-less, partial segments engineered within individual multi-walled carbon nanotubes (MWNTs). Using computational models, we show that an externally applied excitation force can be used to select an operating bearing configuration with a desired stiffness and operating frequency. Our models also demonstrate the possibility of simultaneous, independent operation of multiple bearings within a single NT segment, paving the way towards ultra-high device densities with molecular-scale footprints.