Enhanced Stability of LISs on Bionic Sharkskin Structures through Coating Silica Nanoparticles

In recent decades, liquid-infused surfaces (LISs) inspired by the bionic structure of the pitcher plant have attracted widespread attention in both fundamental and practical applications. The poor stability resulting from the loss of the lubricating oil is always troubling people. Researchers have developed several methods to enhance the stability; however, a general strategy for constructing stable LISs on existing surface structures while keeping the original functions of the structures is still rare. In this study, a bionic sharkskin surface structure was selected as the substrate; by simply coating nanostructures, a high-stability LIS was successfully fabricated, which can withstand up to 5000 rpm centrifugal force and demonstrates excellent stability in static underwater immersion, dynamic shaking underwater, water flow scouring, and acidic/basic/salty solution immersion tests. It is worth noting that the functions such as antifouling and drag reduction of the original bionic sharkskin surface structure can be further enhanced after coating the nanostructure. Theoretical analysis indicates that the enhanced wetting performance of the surface is due to the formation of a stable and relatively continuous oil film on the groove arrays under the action of the nanostructure. This work presents a simple and universal solution to the challenge of fabricating high-stability LISs on existing substrates while maintaining the function of the original structure. This approach will contribute to further development and practical applications of LISs in industrial settings.