Bio-inspired design of ice-retardant devices based on benthic marine invertebrates: the effect of surface texture

Abstract

Growth of ice on surfaces poses a challenge for both organisms and for devices that come into contact with liquids below the freezing point. Resistance of some organisms to ice formation and growth, either in subtidal environments (e.g., Antarctic anchor ice), or in environments with moisture and cold air (e.g., plants, intertidal) begs examination of how this is accomplished. Several factors may be important in promoting or mitigating ice formation. As a start, here we examine the effect of surface texture alone. We tested four candidate surfaces, inspired by hard-shelled marine invertebrates and constructed using a three-dimensional printing process. We examined sub-polar marine organisms to develop sample textures and screened them for ice formation and accretion in submerged conditions using previous methods for comparison to data for Antarctic organisms. The sub-polar organisms tested were all found to form ice readily. We also screened artificial 3-D printed samples using the same previous methods, and developed a new test to examine ice formation from surface droplets as might be encountered in environments with moist, cold air. Despite limitations inherent to our techniques, it appears surface texture plays only a small role in delaying the onset of ice formation: a stripe feature (corresponding to patterning found on valves of blue mussels, Mytilus edulis, or on the spines of the Antarctic sea urchin Sterechinus neumayeri) slowed ice formation an average of 25% compared to a grid feature (corresponding to patterning found on sub-polar butterclams, Saxidomas nuttalli). The geometric dimensions of the features have only a small (∼6%) effect on ice formation. Surface texture affects ice formation, but does not explain by itself the large variation in ice formation and species-specific ice resistance observed in other work. This suggests future examination of other factors, such as material elastic properties and surface coatings, and their interaction with surface pattern.

3D Printing: Applications in evolution and ecology

“…In an examination of ice formation on surfaces, 3D printing was used to replicate surface textures of blue mussels, ( Mytilus edulis ), Antarctic sea urchin ( Sterechinus neumayeri ), and sub‐polar butterclams ( Saxidomas nuttalli ) (Figure a). MehrabaniRay, Tse, and Evangelista () found that the ridges and bumps present on all tested surfaces reduced ice formation at −20°C, but the role of surface texture was limited to approximately 6%. Such 3D models have the advantage of having the same material properties, allowing only the variable under investigation to be modified.…”

“…Examples of 3D printed objects from the studies described in the text. (a) Top, Butterclam shell ( Saxidomas nuttalli ), and below textured 3D print replicating surface structure to test ice formation (Mehrabani et al, ). Reproduced with permissions from PeerJ.…”