Springtail-inspired superomniphobic surface with extreme pressure resistance

Abstract

Both high static repellency and pressure resistance are critical to achieving a high-performance omniphobic surface. The cuticles of springtails have both of these features, which result from their hierarchical structure composed of primary doubly reentrant nanostructures on secondary microgrooves. Despite intensive efforts, none of the previous studies that were inspired by the springtail were able to simultaneously achieve both high static repellency and pressure resistance because of a general trade-off between these characteristics. We demonstrate for the first time a springtail-inspired superomniphobic surface displaying both features by fabricating a hierarchical system consisting of serif-T-shaped nanostructures on microscale wrinkles, overcoming previous limitations. Our biomimetic strategy yielded a surface showing high repellency to diverse liquids, from water to ethanol, with a contact angle above 150 degrees. Simultaneously, the surface was able to endure extreme pressure resulting from the impacts of drops of water and of ethylene glycol with We 200, and of ethanol with We similar to 53, which is the highest pressure resistance ever reported. Overall, the omniphobicity of our springtail-inspired fabricated system was found to be superior to that of the natural springtail cuticle itself.