Molecular motors are molecules that transduce optical or chemical energy into mechanical motions, such as translation and rotation, through cyclic conformational changes . Naturally occurring molecular motors, such as ATP synthase and myosin, have evolved to support many essential biological functions .It has also been argued that even enzymes not usually thought of as molecular motors, such as adenosine kinase, must exhibit at least weak motor-like properties, as a direct consequence of their being thrown back and forth between multiple chiral free energy surfaces corresponding to their apo and substrate-bound states . The same fundamental principles also apply to non-biological molecules, and indeed, exciting progress has also been made in the design and synthesis of artificial molecular motors that may mimic or even surpass their biological counterparts .