Dry-released nanotubes and nanoengines by particle-assisted rolling.

Surface tension of self-assembled metal nanodroplets can be applied to overcome the deformation barriers of strain-engineered nanomembranes and produce extremely nanoscale tubes. Aggregated nanoparticles stress nanomembranes and subsequently integrate on the walls of rolled-up nanotubes, which can speed up the tubular engines owing to the enhanced electrocatalytic activity.