Nanoscale helix rotation powered by a gas concentration gradient

Directing the motion of matter at the nanoscale remains an important goal of nanotechnology. Macroscopic physical principles sometimes transfer to nanoscale systems, as was observed in our recent all-atom molecular dynamics study of a DNA helix rotating due to a water flux generated by a strong pressure gradient or applied electrical field being deflected by the helical shape of the DNA . Here we describe a proof-of-concept investigation that examines the conditions where a rigid, helical nanoscale object situated within a pore can be driven to rotate by a concentration gradient of a noble gas. This process would be challenging to study experimentally, and therefore we employ molecular dynamics simulations modeling the helix as a rigid body and noble gas atoms as point-like particles. We demonstrate rotation under a variety of conditions, exploring the impacts of pore radius, gas type, and concentration, on gas flow and rotation rate. Our findings provide predictive insights into the relationship between gas dynamics and rotation of a helical object, facilitating experimental design in laboratory settings.