Bioinspired Topological Surfaces for Mitigating Water, Thermal and Energy Crises

CONSPECTUS: The remarkable advances in technical and industrial fields have stimulated the world's economic prosperity and population growth while also exacerbating the global water, thermal, and energy crises. To mitigate these crises, numerous large-scale devices have been constructed to harvest water, dissipate heat, and generate energy, yet they still encounter several bottlenecks, such as bulky size and climatic and/or geographic constraints. In contrast, miniature and portable water-based devices have demonstrated their tremendous potential in water harvesting and thermal/energy management due to the ubiquitous existence, large phase-change latent heat, and abundant kinetic energy of water. Owing to the strong dependence of their performance on the interfacial interactions between water and a surface, designing novel surface topology, in both physical and chemical aspects, is of practical importance to impart them with the ability to control the interfacial interaction/exchange among water, heat, and energy in an efficient, precise, and programmable manner.Developing novel, functional, and topological surfaces can involve learning from nature because many living organisms have evolved functional surface topologies to fundamentally tailor their interactions with liquids to survive in complicated and harsh environments. Although great progress has been made in bioinspired topological surfaces, two major bottlenecks consisting of a fundamental understanding and practical applications remain elusive. From the perspective of a fundamental understanding, the principles by which the surface topology of an organism controls the dynamic behavior of water droplets need to be deciphered comprehensively. From the perspective of practical applications, rationally designing surface topologies to achieve multifunctionality in industrial processes, especially in complex and harsh conditions, is of great importance. In this Account, we systematically review our recent progress in promoting bioinspired topological surfaces toward practical applications. We start with a fundamental investigation of various topological surfaces for rapid droplet bouncing facilitated by specific surface structures or a slippery liquid film. Subsequently, we introduce different surface topology designs for directional liquid transport. On the basis of these fundamental understandings, we further demonstrate their representative practical applications, including water harvesting, thermal management, and energy conversion. Finally, we offer a brief summary and perspectives on the development of novel bioinspired topological surfaces.