Switchable Direction of Liquid Transport via an Anisotropic Microarray Surface and Thermal Stimuli.

Design and construction of special surface microstructures has made many amazing breakthroughs in directional liquid transport. Despite much progress in this field, challenges still remain in on-demand switchable direction transport of liquid in situ and real-time via transforming the arrangement of the surface microstructure and external stimuli. Herein, we demonstrate a strategy to achieve switchable direction transport of liquid via a tunable anisotropic microarray surface, that is, assembling a V-shaped prism microarray (VPM) surface, which can also be intelligently manipulated by thermal stimuli. By transforming the parallel and staggered prism microstructure arrangement of the VPM, switchable direction transport of a liquid can be successfully achieved on the VPM surface. Flow direction switching among unidirectional transport, bidirectional transport, and reverse unidirectional transport is also achieved on the temperature-adaptive VPM surface by thermal stimuli, which can be used for on-demand liquid transport according to the paths of the microfluidic channels. The work provides a way for precise liquid manipulation in desired liquid transport, which may be utilized in nonpower conveying systems, autolubrication, life fluid medical instruments, and other microfluidic devices.