Lubricant Depletion‐Resistant Slippery Liquid‐Infused Porous Surfaces via Capillary Rise Lubrication of Nanowire Array

Abstract Despite their promise in diverse applications, lubricant depletion over time presents an important challenge for slippery lubricant‐infused porous surfaces (SLIPS). The main source of lubricant depletion is the growth of a wetting ridge around a droplet of foreign liquid that removes the infused lubricant from the porous surface when the droplet slides off. This work describes the fabrication of liquid‐infused ZnO nanowire array by capillary rise lubrication and the effect of array morphology on suppressing wetting ridge formation. The orientation of nanowires strongly affects lubricant infiltration and the stability of SLIPS properties. The infiltrated lubricant in random ZnO nanowire arrays does not form a visible wetting ridge around a water droplet because of the strong capillarity that retains the lubricant confined in the nanoporous structure. The lack of wetting ridge gives rise to a stable SLIPS that exhibits self‐recovery of the infused lubricant. Such a structure retains lubricant under a strong centrifugal force, showing high stability. This study provides a straightforward, robust, and potentially scalable approach for making stable SLIPS that suppresses lubricant depletion by taking advantage of the unique morphology of the random nanowire arrays and capillary rise lubrication.