Freezing drop impact

We investigate experimentally the solidification of a water drop during its impact on a sub-zero cooled metallic plate. As the drop impacts the substrate, a first thin layer of ice builds-up in the briefest moment. Once this frozen disc is formed, the remaining liquid retracts on the top of it. The competition between this capillary retraction and the liquid solidification leads to a variety of frozen drop patterns. Typically, with a change of temperature the drop can freeze into a fried egg or a doughnut shape. Experimental measurements of the frozen drop profile, a 1D solidification model, and relevant scaling laws allow us to characterize the frozen disc thickness, and the different patterns, as a function of the control parameters.