3D-printed modular platform for path-customizable liquids transport

[Display omitted] •A bionic unidirectional liquid transport platform over long distance was proposed.•Crescent-shaped groove was designed to overcome the liquid resistance at the joints.•The platforms with customized liquid transport trajectories were flexibly designed.•Liquid transport, such as anti-gravity transport and liquid splitting, were realized. Spontaneous liquid transport is increasingly being applied in various fields such as microfluidics, fuel cells, phase change heat transfer, water harvesting, etc. However, long-distance spontaneous liquid transport with path-customizable motion trajectories is still challenging. Drawing multi-inspirations from the wedge-shaped structures of iris petals, the continuous structures of bamboo joints, and the microgroove structures of Nepenthes mouth edge, we fabricate a modular, pump-free biomimetic liquid transport platform by 3D printing and surface modification. The platform is composed of sequential wedge notches, and a crescent-shaped groove is designed at the joint of every two connected wedge structures. The platform is characterized by path-customizable liquid transport trajectories and can be used to achieve long-distance liquid transport without the need of external energy fields, and the multi-level nested structures along the depth significantly facilitates the liquid transport. Experimental study and theoretical force analysis show that the crescent-shaped grooves enable the liquid to overcome joint barriers by converting potential energy accumulated at joints into kinetic energy, achieving a maximum velocity of 18 mm/s. Taking advantage of the flexibility of 3D printing and long-distance transport capability, the modular structure of the platform enables customization of the transport distance and trajectory. By assembling 14 bamboo-like wedge-shaped units in series, we realized a transport distance up to 350 mm, which could be further increased by connecting more units. Furthermore, we develop various modular and multifunctional liquid transport platforms for anti-gravity transport, liquid diversion, and customized transport trajectories, which demonstrate that our design strategy could be an available solution for path-customizable liquids transport in fields like bio-sensing, fuel cells, etc.