  The Leidenfrost transition leads a boiling system to the boiling crisis, a
state in which the liquid loses contact with the heated surface due to
excessive vapor generation. Here, using experiments of liquid droplets boiling
on a heated surface, we report a new phenomenon, termed oscillating boiling, at
the Leidenfrost transition. We show that oscillating boiling results from the
competition between two effects: separation of liquid from the heated surface
due to localized boiling, and rewetting. We argue theoretically that the
Leidenfrost transition can be predicted based on its link with the oscillating
boiling phenomenon, and verify the prediction experimentally for various
liquids.
