Designing Leidenfrost drops

Large Leidenfrost drops exhibit erratic bubble bursts to release vapor accumulated beneath the liquid, becoming amorphous and unstable. Here we report an original and remarkably simple method to stabilize and design a Leidenfrost puddle. When a thin hydrophilic layer with a suitable design is placed over the liquid, the puddle adopts the layer shape due to adhesive forces and becomes stable. We show a wide variety of designs obtained using this method. Moreover, we determine the required layer dimensions to stabilize puddles, the wetting and floating conditions, and a model for the evaporation rate of the designed drops. Finally, potential applications are highlighted.