Natural organisms have evolved a series of versatile functional biomaterials and structures to cope with survival crises in their living environment, exhibiting outstanding properties such as superhydrophobicity, anisotropy, and mechanical reinforcement, which have provided abundant inspiration for the design and fabrication of next-generation multi-functional devices. However, the lack of available materials and limitations of traditional manufacturing methods for complex multiscale structures have hindered the progress in bio-inspired manufacturing of functional structures. As a revolutionary emerging manufacturing technology, additive manufacturing (i.e., 3D printing) offers high design flexibility and manufacturing freedom, providing the potential for the fabrication of intricate, multiscale, hierarchical, and multi-material structures. Herein, a comprehensive review of current 3D printing of surface/interface structures, covering the applied materials, designs, and functional applications is provided. Several bio-inspired surface structures that have been created using 3D printing technology are highlighted and categorized based on their specific properties and applications, some properties can be applied to multiple applications. The optimized designs of these 3D-printed bio-inspired surfaces offer a promising prospect of low-cost, high efficiency, and excellent performance. Finally, challenges and opportunities in field of fabricating functional surface/interface with more versatile functional material, refined structural design, and better cost-effective are discussed. Several 3D printed bio-inspired surface structures are demonstrated in aspect of the applied materials, functional designs, and various applications. Based on the applications, the design of the 3D-printed structures can be categorized as superhydrophobic structures, structures for drag force reduction, microscale surface structures with anisotropic water transport, surfaces for water collection and oil/water separation, and micro-needle structures. The optimized designs of the 3D-printed bio-inspired surface structures will have a promising potential as the next generation of multi-functional materials with low-cost, high efficiency, and excellent performance.image
