Gear Junctions between Chiral Boron Nitride Nanotubes

TL;DR

This study demonstrates gear-like motion transmission at junctions between boron nitride nanotubes, showing how their chiral structure influences motion transfer efficiency through atomistic simulations.

Contribution

It reveals the gear effect at BNNT junctions and elucidates how chiral angles affect motion transmission, a novel insight into nanoscale mechanical interactions.

Findings

Motion can be transmitted between BNNTs at junctions via non-covalent interactions.

Transmission efficiency varies with chiral angle and displacement rate.

Parallel and cross junctions exhibit different dependencies on chiral angles.

Abstract

A gear effect is demonstrated at parallel and cross junctions between boron nitride nanotubes (BNNTs) via atomistic simulations. The atoms of neighboring BNNTs are meshed together at the junctions like gear teeth through long-range non-covalent interaction, which are shown to be able to transmit motion and power. The sliding motion of a BNNT can be spontaneously translated to rotating motion of an adjoining one or viceversa at a well-defined speed ratio. The transmittable motion and force strongly depend on the helical lattice structure of BNNTs represented by a chiral angle. The motion transmission efficiency of the parallel junctions increases up to a maximum for certain BNNTs depending on displacement rates. It then decreases with increasing chiral angles. For cross junctions, the angular motion transmission ratio increases with decreasing chiral angles of the driven BNNTs, while the translational one exhibits the opposite trend.