A nanoscale rotor made from DNA could be used as a tiny valve for tasks like sorting molecules or it could act as a switch in a biological computer.
Designing moving mechanical systems at nanoscale is difficult because of the random movements of small molecules, which knocks components back and forth. There are many examples of effective biological motors in nature, such as F-ATPase, an energy-producing enzyme with a central rotating column, but functioning synthetic nanomotors had yet to be built.