Dependency of ice adhesion strength on surface wettability and roughness*

Ice adhesion mechanisms are poorly understood contributing to the limited effectiveness of current ice mitigation techniques.The ideal solution is to prevent ice accretion via suppression of ice adhesion on ice-phobic surfaces, which requires understanding ice-phobicity at a more fundamental level. Given the breadth of published results, we designed an experimental matrix to isolate the effects of roughness and dynamic water spreading on ice adhesion. To this end, we conducted detailed surface roughness maps and novel dynamic contact angle measurements on stainless steel, aluminum, and non-metallic materials. We varied temperature to evaluate a variety of conditions encountered in practice such as clear ice, mixed ice and rime ice. Dynamic hysteresis of the contact angle and adhesion are clear functions of the forcing frequency and amplitude as well as surface roughness in pendant drop experiments. These results are a step towards finding physics-based solutions to ice accretion challenges.