  Flow-driven rotary motors drive functional processes in human society such as
windmills and water wheels. Although examples of such rotary motors also
feature prominently in cell biology, their synthetic construction at the
nanoscale has thus far remained elusive. Here, we demonstrate flow-driven
rotary motion of a self-organized DNA nanostructure that is docked onto a
nanopore in a thin solid-state membrane. An elastic DNA bundle self assembles
into a chiral conformation upon phoretic docking onto the solid-state nanopore,
and subsequently displays a sustained unidirectional rotary motion of up to 20
revolutions/s. The rotors harness energy from a nanoscale water and ion flow
that is generated by a static (electro)chemical potential gradient in the
nanopore that is established through a salt gradient or applied voltage. These
artificial nanoengines self-organize and operate autonomously in physiological
conditions, paving a new direction in constructing energy-transducing motors at
nanoscale interfaces.
