  We use molecular dynamics simulations to investigate the displacement of a
simple butterfly-like molecular motor inside nanopores of various radii filled
with a viscous medium. The medium is modeled with a versatile potential that
may be adjusted to represent a large number of materials. It was found
previously that the motor folding not only increases its displacement but also
creates elementary diffusion processes inside the medium, related to the
opening angle of the motor folding. The presence of these processes changes the
medium dynamics and in turn affects the motor displacement. Therefore we test
the motor displacement with different activations of the medium inside the pore
by varying the motor opening angles. We find that the optima of the motor
displacement oscillate with pore sizes and that the optimal radii depend on the
activation of the medium. These results imply that it is possible to choose the
activation or opening angle that optimizes the motor displacement for a given
pore size. Results also show that the activation decreases strongly the
confinement hindering of the motor motion, in particular for small pores.
Finally, analyzing the distribution probability of the motor position and the
density of elementary motions we find that the motor is mainly located in the
center of the pore. We find spikes in the density of elementary motions when
the motor goes away from the center, suggesting important contributions of the
motor bouncing motions on the pore walls.
