Bamboo-joint-like platforms for fast, long-distance, directional, and spontaneous transport of fluids.

Spontaneous transport of fluids without external force offers an enabling tool for a wide spectrum of fields. However, the development of a universal spontaneous transport platform for liquids remains a challenge. In this work, a novel bamboo-joint-like platform with tapered micro-tubes as transport units is presented, which not only enables the spontaneous transport and extrusion of liquids but also enables customized and optional assembly of transport devices. Spontaneous transport characterized with long-distance, anti-gravity transport, directional transport, and liquid extrusion characteristics was found to show excellent transport capacity. The results indicated that both transport distance and speed varied periodically with time, which was mainly due to the difference in curvature caused by asymmetric structure and capillary force. The desired spontaneous transportation was successfully obtained even when the supply rate speed was up to 632.5 μl/min and length of platform reached a scale of hundreds of millimeters. Transport units were easily fabricated via a commercially available 3D printing technique, so that the customized and directional spontaneous directional transport can be realized for liquid distribution, serpentine loop transportation, and speed control. With the comprehensive use of transport units and connectors, it is very easy to implement self-service construction of a universal complex multi-functional transportation platform.