Multi-Scale Textured Surface Designs with Passive Frost-Resistant Capabilities

The need for anti-frosting surfaces is continued and ever-present. These surfaces aim to intrinsically resist frost formation. Long-term frost resistance is incredibly valuable for regions that regularly experience freezing conditions, especially for above-ground power cables, aircraft airfoils, and satellite dishes, among numerous others. Here, we introduce new guidelines for multi-scale surface designs that passively promote increased frost-free regions over long periods of time. By combining geometries and material properties over multiple length scales, we can effectively manipulate the diffusion flux field of incoming water vapor to create two distinct regions: (1) a sacrificial region with the majority of frost growth and (2) a large non-frosted region that resists frost growth. While millimeter-sized features alone can partially have this effect, it can be enhanced by ~50% and in some cases up to a three-fold increase in the frost-free areal portion by the addition of Graphene Oxide (GO) dough. Utilizing the properties of GO doughs, namely permeability and anisotropic heat transfer, in conjunction with anisotropic mass transfer on macrotextures, we can successfully control the size of the frost-free region, thereby mitigating frost-related material/performance degradation.