  Downsizing microswimmers to the nanoscale, and using light as an externally
controlled fuel, are two important goals within the field of active matter.
Here we demonstrate using all-atom molecular dynamics simulations that
solvation relaxation, the solvent dynamics induced after visible light
electronic excitation of a fluorophore, can be used to propel nanoparticles
immersed in polar solvents. We show that fullerenes functionalized with
fluorophore molecules in liquid water exhibit substantial enhanced mobility
under external excitation, with a propulsion speed proportional to the power
dissipated into the system. We show that the propulsion mechanism is
quantitatively consistent with a molecular scale instance of
self-thermophoresis. Strategies to direct the motion of functionalized
fullerenes in a given direction using confined environments are also discussed.
