Structure-enabled liquid manipulation: bioinspired control across all dimensions

Directional liquid manipulation underpins critical processes across nature and engineering, where targeted functionality demands precise control over fluid behaviour. While fundamental theories for liquid manipulation are well-established, optimizing control along application-specific minimal-path trajectories remains a significant challenge. This review discusses recent advances in bioinspired strategies and engineered manipulators enabling superior liquid directional control across dimensional frameworks: 1D trajectories for targeted delivery, 2D planes for complex transport, and 3D spaces for programmable interfaces. Drawing on nature's energy-efficient principles, from Laplace pressure gradients to capillary effects, we decode evolutionary-optimized liquid manipulation mechanisms and their translation into dimension-specific artificial systems. These manipulators achieve precise liquid guidance through simplified asymmetric architectures, enhancing liquid utilization efficiency. Finally, we outline design paradigms for next-generation on-demand liquid control systems, bridging interfacial phenomena with microfluidic, thermal, and environmental technologies.