Fast Responsive and Controllable Liquid Transport on a Magnetic Fluid/Nanoarray Composite Interface
Fast Responsive and Controllable Liquid Transport on a Magnetic Fluid/Nanoarray Composite Interface
复制标题
磁流体/纳米阵列复合界面上的快速响应和可控液体传输
DOI：
10.1021/acsnano.6b02318
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发表时间：
2016-06-01
期刊：
影响因子：
17.1
通讯作者：
Dou, Shi Xue
中科院分区：
文献类型：
--
作者：
Tian, Dongliang;Zhang, Na;Dou, Shi Xue
通过调节表面张力/拉普拉斯压力和外界刺激的梯度，液体在表面上的传输是可控的，这在固、液界面上已经得到了广泛的研究。然而，它仍然面临着响应速度慢，传输速度和方向无法控制的挑战。在这里，我们展示了通过调制外部磁场，在智能磁性流体/纳米阵列界面，即复合界面上快速响应和可控的液体传输。复合材料界面对水的润湿性是对梯度磁场的瞬时响应，这是由于磁驱动的复合材料界面的梯度粗糙度转变发生在毫秒内，这至少比其他响应表面快一个数量级。当水滴响应于梯度磁场运动时，它可以跟随梯度复合界面结构的运动。此外，还可以通过调节梯度磁场的运动方向来控制水滴的传输方向。该复合界面可以作为泵在微通道中输送不相容的液体和其他物体，这为设计智能界面材料和微流控器件提供了一种方法。
Controllable liquid transport on surface is expected to occur by manipulating the gradient of surface tension/Laplace pressure and external stimuli, which has been intensively studied on solid or liquid interface. However, it still faces challenges of slow response rate, and uncontrollable transport speed and direction. Here, we demonstrate fast responsive and controllable liquid transport on a smart magnetic fluid/nanoarray interface, i.e., a composite interface, via modulation of an external magnetic field. The wettability of the composite interface to water instantaneously responds to gradient magnetic field due to the magnetically driven composite interface gradient roughness transition that takes place within a millisecond, which is at least 1 order of magnitude faster than that of other responsive surfaces. A water droplet can follow the motion of the gradient composite interface structure as it responds to the gradient magnetic field motion. Moreover, the water droplet transport direction can be controlled by modulating the motion direction of the gradient magnetic field. The composite interface can be used as a pump for the transport of immiscible liquids and other objects in the microchannel, which suggests a way to design smart interface materials and microfluidic devices.