Lee Sang-Hyeon, Seong Minho, Kwak Moon Kyu, Ko Hyunwook, Kang Minsu, Park Hyung Wook, Kang Seong Min, Jeong Hoon Eui
Department of Mechanical Engineering , Ulsan National Institute of Science and Technology (UNIST) , Ulsan , Republic of Korea 44919.
Department of Mechanical Engineering , Kyungpook National University , Daegu , Republic of Korea 41566.
ACS Nano. 2018 Nov 27;12(11):10693-10702. doi: 10.1021/acsnano.8b05109. Epub 2018 Sep 28.
Anti-icing materials that can efficiently limit ice formation have a strong potential to replace existing anti-icing techniques, such as Joule heating, chemical release, or mechanical removal, which are usually inefficient, expensive, and environmentally harmful. In this study, an anti-icing material based on a magnetically responsive hierarchical hair array that can actively modulate drop bouncing dynamics is presented. The magnetically responsive hair array exhibits an immediate and reversible structural bending motion in response to an external magnetic field. The array also exhibits superhydrophobicity, regardless of its tilt angle, due to the tapered geometry of the hairs and the multiscale surface roughness of the array. Due to its dynamic structure and water-repellent characteristics, the array can induce distinct multiple modes of drop bouncing behavior by adjusting its structural bending state in a reversible fashion. Three different types of bouncing behavior, namely, quasi-pancake bouncing, directional bouncing, and macrotexture-induced droplet fragmentation, can be obtained with the vertical, tilted, and fully bent hair arrays, respectively. We demonstrate that the dynamically controllable drop bouncing behavior of the magnetically responsive hierarchical array enables the efficient and robust prevention of ice formation and accumulation.
能够有效限制结冰的防冰材料具有强大潜力，可取代现有的防冰技术，如焦耳加热、化学释放或机械清除，这些技术通常效率低下、成本高昂且对环境有害。在本研究中，展示了一种基于磁响应分级毛发阵列的防冰材料，该阵列能够主动调节液滴弹跳动力学。磁响应毛发阵列在外部磁场作用下呈现即时且可逆的结构弯曲运动。由于毛发的锥形几何形状和阵列的多尺度表面粗糙度，该阵列无论倾斜角度如何都表现出超疏水性。由于其动态结构和疏水特性，该阵列可以通过以可逆方式调整其结构弯曲状态来诱导不同的多种液滴弹跳行为模式。分别使用垂直、倾斜和完全弯曲的毛发阵列可获得三种不同类型的弹跳行为，即准煎饼弹跳、定向弹跳和宏观纹理诱导的液滴破碎。我们证明，磁响应分级阵列的动态可控液滴弹跳行为能够高效且有力地防止结冰和积冰。
