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Mitigating icing hazards is of interest for many technological applications. One solution is to employ low ice adhesion coatings, either passively or in combination with active de-icing systems. Nevertheless, comparing different low ice adhesion surfaces can be challenging. Studies generally report the average shear stress, calculated as the ratio of applied force to the ice-substrate contact area; however, the fracture mechanism at the ice-substrate interface is rarely reported. There are two fracture mechanisms that can occur at the interface: stress-dominated and toughness-dominated. Average shear stress is only meaningful when performing adhesion tests in a stress-dominated regime; otherwise, interface stresses are underestimated and misleading. This study presents a new understanding of ice adhesion mechanisms combining experimental and numerical methods, demonstrating how the traditional ice adhesion reporting method can lead to errors up to 400%. Using a simple fracture model, the study shows that the stress-dominated fracture regime in the horizontal push test is favored by smaller ice diameter and greater ice thickness, and is also affected by the load force position. The identification of the two fracture regimes is required for the correct understanding and reproducibility of ice adhesion results, enabling better design and characterization of icephobic coatings and materials.

Controlling water transport and management is crucial for continuous and reliable system operation in harsh weather conditions. Passive strategies based on nonwetting surfaces are desirable, but so far, the implementation of superhydrophobic coatings into real-world applications has been limited by durability issues and, in some cases, lack of compliance with environmental regulations. Inspired by surface patterning observed on living organisms, in this study we have developed durable surfaces based on contrast wettability for capillary-driven water transport and management. The surface fabrication process combines a hydrophobic coating with hard-anodized aluminum patterning, using a scalable femtosecond laser microtexturing technique. The concept targets heavy-duty engineering applications; particularly in aggressive weather conditions where corrosion is prevalent and typically the anodic aluminum oxide-based coating is used to protect the surface from corrosion, the concept has been validated on anodic aluminum oxide coated aluminum alloy substrates. Such substrates with contrast wettable characteristics show long-term durability in both natural and lab-based artificial UV and corrosion tests where superhydrophobic coatings tend to degrade.

Surfaces with low ice adhesion are crucial for many technological and societal applications. However, comparing the performance of different surface coatings still represents a major challenge, given the broad range of ice accretion and removal conditions. One of the most common methodologies relies on measuring ice adhesion, which is often quantified by the shear strength of the ice-substrate interface. Nevertheless, large discrepancies up to one order of magnitude exist among the shear strength values reported in the literature for similar test conditions. This work compares shear strength measurements between two inherently different ice adhesion measurement techniques: (i) a dynamic, vibratory approach and (ii) a more traditional static push test on a horizontal surface. By employing a hybrid experimental and numerical approach, the shear strength is obtained for both techniques. This approach allows a direct correlation between a low-complexity static setup and a dynamic test rig, close to the operating conditions of vibratory applications but more challenging to implement. As such, this study enables a better understanding and design of ice adhesion measurement procedures for testing both traditional and icephobic surfaces.