  Like their larger micron-scale counterparts, {\AA}ngstr\"om-scale chemically
self-propelled motors use asymmetric catalytic activity to produce
self-generated concentration gradients that lead to directed motion. Unlike
their micron-scale counterparts, the sizes of {\AA}ngstr\"om-scale motors are
comparable to the solvent molecules in which they move, they are dominated by
fluctuations, and they operate on very different time scales. These new
features are studied using molecular dynamics simulations of small sphere dimer
motors. We show that the ballistic regime is dominated by the thermal speed but
the diffusion coefficients of these motors are orders of magnitude larger than
inactive dimers. Such small motors may find applications in nano-confined
systems or perhaps eventually in the cell.
