We have observed a novel phenomenon by which asymmetrically structured surfaces can be used to direct the motion of film boiling droplets without applying an external force to the system. Droplets placed on such a surface move in a preferred direction, and under common conditions accelerate in that direction. In this thesis, we present a phenomenological description of the observed behavior, and develop a mathematical model for the motion of droplets on ratchet and non-ratchet surfaces. Using this model, we show that asymmetry is a requisite of the observed behavior. We also show that surface and droplet properties influence the resulting acceleration.
