Ice Nucleation Regulation by Nanoscale Surface Topography

Heterogeneous ice nucleation, triggered by surfaces, profoundly impacts climate systems, biological processes, and technological applications. Classical nucleation theory (CNT) predicts that with curvature radii decreasing within 1 order of magnitude of the critical nucleus radius, convex surfaces should suppress nucleation and concave surfaces should promote nucleation; however, such regularity has not been observed explicitly in experiments, and there are even conflicting results. Here, we resolve this long-standing controversy by providing the first experimental evidence about the bidirectional regulation of ice nucleation from both liquid and vapor phases through precisely engineered convex (nanosphere) and concave (nanopore) surfaces. Systematic experiments reveal size-dependent trends: as curvature radii decrease at the critical nucleus scale, ice nucleation temperatures and rates decrease on convex but increase on concave surfaces, directly linked to opposing nucleation free energy barrier variations that align with CNT predictions. This work bridges CNT's predictions for surface topography with practical ice-control engineering.