Snowphobic Behavior of Needle-Like Surfaces*

Numerous icing-induced hazards occur due to snow accumulation on surfaces such as electrical wires and poles in extremely cold, humid environments. Needle-like leaves of some conifer species such as the pine trees can exhibit effective snowphobic behavior to survive in such harsh winter environments by localizing snow and minimizing snow accumulation. We hypothesize that the hierarchical structure of the pine leaves and the arrangement of the leaves effectively reduce the effects of snow and partially melted snow. Experimentally, and numerically, we observe and analyze the deposition and removal mechanism of snow on real conifer leaf samples as well as on artificial samples with hierarchical structures. We further investigate various phase change of snow, leading to partially melted snow and water vapor flux diffusion associated with preventing the leaf stems from icing problems. This research will provide important insights while designing functional snowphobic surfaces by employing hierarchical features under various forced convection conditions.