In Situ Multi‐Directional Liquid Manipulation Enabled by 3D Asymmetric Fang‐Structured Surface

• Published in: Advanced materials (Weinheim) Vol. 36; no. 38; pp. e2407034 - n/a
• Main Authors: Sun, Siqi, Zhang, Yiyuan, Wu, Shuangmei, Wang, Liqiu
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.09.2024
• Subjects: asymmetric fang‐structured surface; Controllability; Directional control; liquid spreading control; Liquids; multi‐directional liquid manipulation; Pressure gradients; Surface tension; Wettability; Wetting; multi‐directional liquid manipulation; liquid spreading control; asymmetric fang‐structured surface; surface tension
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202407034

Decorating surfaces with wetting gradients or topological structures is a prevailing strategy to control uni‐directional spreading without energy input. However, current methods, limited by fixed design, cannot achieve multi‐directional control of liquids, posing challenges to practical applications. Here, a structured surface composed of arrayed three‐dimensional asymmetric fang‐structured units is reported that enable in situ control of customized multi‐directional spreading for different surface tension liquids, exhibiting five novel modes. This is attributed to bottom‐up distributed multi‐curvature features of surface units, which create varied Laplace pressure gradients to guide the spreading of different‐wettability liquids along specific directions. The surface's capability to respond to liquid properties for multimodal control leads to innovative functions that are absent in conventional structured surfaces. Selective multi‐path circuits can be constructed by taking advantage of rich liquid behaviors with the surface; surface tensions of wetting liquids can be portably indicated with a resolution scope of 0.3–3.4 mN m−1 using the surface; temperature‐mediated change of liquid properties is utilized to smartly manipulate liquid behavior and achieve the spatiotemporal‐controllable targeted cooling of the surface at its heated state. These novel applications open new avenues for developing advanced surfaces for liquid manipulation. The carefully designed fang‐structured surface generates a unique distributed 3D multi‐curvature, yielding a response to liquid surface tension for customized control of multi‐directional liquid spreading. This enables innovative functions beyond conventional surfaces, including constructing selective multi‐path circuits, portably indicating surface tensions of wetting liquids with a resolution of 0.3–3.4 mN m−1, and temperature‐mediated smart manipulation of liquids.