Magnetically Responsive Superhydrophobic Surface: In Situ Reversible Switching of Water Droplet Wettability and Adhesion for Droplet Manipulation
Magnetically Responsive Superhydrophobic Surface: In Situ Reversible Switching of Water Droplet Wettability and Adhesion for Droplet Manipulation
复制标题
磁响应超疏水表面：水滴润湿性和粘附力的原位可逆切换，用于液滴操纵
DOI：
10.1021/acsami.8b04190
复制
发表时间：
2018-06-13
影响因子：
9.5
通讯作者：
Li, Gang
中科院分区：
文献类型：
--
作者：
Yang, Chao;Wu, Lei;Li, Gang
采用喷雾涂层和磁场定向自组装相结合的方法，可以很容易地制备出灵巧、磁敏的超疏水表面。表面由密集的磁流变弹性体微柱(MREMPs)阵列组成。得益于MREMPs的磁场硬化效应，表面表现出润湿性和附着力的可逆切换，这是对开/关磁场的响应。考察了不同磁场下MREMPs表面的润湿性和粘附性。结果表明，这些表面的粘附力和滑动行为强烈依赖于外加磁场的强度和用于制备磁响应超疏水表面的聚二甲基硅氧烷(PDMS)、铁颗粒和溶剂(在溶液中)的混合比例。粘接转变归因于MREMPs的机械性能可调，这很容易受到外部磁场的控制。研究还表明，磁响应型超疏水表面可以作为无损失液滴输送的“机械手”。这种磁性响应的超疏水表面不仅为微流体控制和液滴传输提供了新的接口，还为实现智能防液皮肤、可编程流体收集和传输以及智能微流体设备开辟了新的途径。
A smart, magnetically responsive superhydrophobic surface was facilely prepared by combining spray coating and magnetic-field-directed self-assembly. The surface comprised a dense array of magnetorheological elastomer micropillars (MREMPs). Benefitting from the magnetic field- stiffening effect of the MREMPs, the surface exhibited reversible switching of the wettability and adhesion that was responsive to an on/off magnetic field. The wettability and adhesion properties of the surfaces with MREMPs were investigated under different magnetic fields. The results revealed that the adhesion force and sliding behaviors of these surfaces were strongly dependent on the intensity of the applied magnetic field and the mixing ratio of poly(dimethylsiloxane) (PDMS), iron particles, and solvent (in solution) used for preparation of the magnetically responsive superhydrophobic surfaces. The adhesion transition was attributed to the tunable mechanical properties of the MREMPs, which was easily controlled by an external magnetic field. It was also demonstrated that the magnetically responsive superhydrophobic surface can be used as a "mechanical hand" for no-loss liquid droplet transportation. This magnetically responsive superhydrophobic surface not only provides a novel interface for microfluidic control and droplet transportation, but also opens up new avenues for achieving smart liquid-repellent skin, programmable fluid collection and transport, and smart microfluidic devices.