LAUSR

Directional liquid transport (DLT), especially those proceed on the conical fiber (DLT-CF), is an important mass-transfer process widely used in both natural organisms and practical applications. However, on-site switching the DLT-CF remains a challenge due to the non-tunable driving force imparted by the structural gradient, which greatly limits its application. Here, unprecedently, we developed a facile electrochemical strategy for reaching the on-site switchable DLT-CF, featured as the in situ control and the fast response. Depending on the poised electric potential, the droplet can either move directionally or be pinned at any position for a tunable duration time, exhibiting completely different moving characteristics from the traditional DLT-CF with no control. It is proposed that the surface hysteresis resistance, closely related to both the surface hydrogen-bonding network and the droplet topology on fiber, can be largely altered electrochemically. The tunable hysteresis resistance works synergistically with the conical structure induced Laplace pressure to on-site tune the forces acting on the droplet, leading to various controllable DLTs-CF, including those with the tunable distance and direction, the array manipulation and assembly line processing of droplets. The strategy is applicable for versatile liquids, offering a general approach for the controllable liquid transport in fibrous systems. This article is protected by copyright. All rights reserved.