Directional fluid dynamics has garnered increasing attention because of its extensive applications in diverse fields including water harvesting, anti-icing, and microfluidic manipulation. Natural organisms have evolved a myriad of surfaces with specialized functions that manipulate liquids by virtue of their surface structure and chemical composition. These surfaces provide an extremely rich source of inspiration for controlled fluid transfer. The study of the fundamentals of what happens between droplets and functional surfaces and the close interactions is essential for the development of technologies and solutions in different fields. Exploring the inherent workings of droplet manipulation on natural biosurfaces can inspire the design and development of superwettable materials. This review deepens the understanding of directed fluid dynamics by summarizing interface fluid dynamics theory and mechanisms. It presents the fundamental principles of directed fluid dynamics on typical natural biological surfaces. Additionally, it elucidates the fluid dynamics behavior and applications of a diverse set of smart functional surfaces inspired by natural organisms. Simultaneously, it shares its view on superwetting interface liquid dynamics challenges and opportunities, pushing for next-generation biomimetic superwettable materials.