Durable Icephobic and Superhydrophobic Silicon Nanowire Surfaces.
Seyed Mehran Mirmohammadi, Miika Heikkilä, Laura Fieber, Mohammad Awashra, Sara Hamed, Suprit Bhusare, Gaurav Mohanty, Robin H A Ras, Ville Jokinen, Sami Franssila
Abstract
Open AccessSuperhydrophobic surfaces hold great promise for various engineering applications. However, their fragility and limited durability in real-world scenarios pose significant challenges. Here, a durable superhydrophobic and icephobic surface is fabricated using the metal-assisted chemical etching method to create silicon nanowires within inverted pyramidal microstructures. Mechanical robustness is introduced by applying a hard coating to the structure through titanium film deposition, followed by annealing in a nitrogen atmosphere, which forms titanium silicide and titanium nitride. The hard-coated surfaces can endure up to 60 g of sand abrasion or 20 icing-shearing cycles while still retaining their superhydrophobic properties (advancing and receding contact angles of approximately 150°) and icephobic properties (ice adhesion strength of approximately 10 kPa).