  Inspired by dimeric motor proteins capable of undergoing transportation in
living cells, significant efforts have been expended to the fabrication of
track-walking nanomotors possessing two foot-like components that each can bind
or detach from an array of anchorage groups on the track in response to local
events of reagent consumption. The central problem in fabricating bipedal
nanomotors is how the motor as a whole can gain the synergic capacity of
directional track-walking, given the fact that each pedal component alone often
is incapable of any directional drift. Implemented bipedal motors to date solve
this thermodynamically intricate problem by an intuitive strategy that requires
a hetero-pedal motor, multiple anchorage species for the track, and multiple
reagent species for motor operation. Here we presented a detailed molecular
mechanism by which motor-level directionality arises from a homo-pedal motor
along a minimally heterogeneous track. Optimally, the operation may be reduced
to a random supply of a single species of reagents to allow the motor's
autonomous functioning. The mechanism suggests a distinct class of fabrication
targets of drastically reduced system requirements. Intriguingly, a defective
form of the mechanism falls into the realm of the well known Brownian motor
mechanism, yet distinct features emerge from the normal working of the
mechanism.
