PASTEUR, Department of chemistry, École Normale Supérieure, UPMC Univ. Paris 06, CNRS, PSL Research University, 75005, Paris, France.
Sorbonne Universités, UPMC Univ. Paris 06, École Normale Supérieure, CNRS, PASTEUR, 75005, Paris, France.
Angew Chem Int Ed Engl. 2017 Dec 22;56(52):16565-16570. doi: 10.1002/anie.201710668. Epub 2017 Dec 11.
The magnetic actuation of deposited drops has mainly relied on volume forces exerted on the liquid to be transported, which is poorly efficient with conventional diamagnetic liquids such as water and oil, unless magnetosensitive particles are added. Herein, we describe a new and additive-free way to magnetically control the motion of discrete liquid entities. Our strategy consists of using a paramagnetic liquid as a deformable substrate to direct, using a magnet, the motion of various floating liquid entities, ranging from naked drops to liquid marbles. A broad variety of liquids, including diamagnetic (water, oil) and nonmagnetic ones, can be efficiently transported using the moderate magnetic field (ca. 50 mT) produced by a small permanent magnet. Complex trajectories can be achieved in a reliable manner and multiplexing potential is demonstrated through on-demand drop fusion. Our paramagnetofluidic method advantageously works without any complex equipment or electric power, in phase with the necessary development of robust and low-cost analytical and diagnostic fluidic devices.
沉积液滴的磁驱动主要依赖于对要输送的液体施加的体积力，对于传统的抗磁性液体（如水和油），这种方法效率很差，除非添加磁敏颗粒。在此，我们描述了一种新的、无需添加物的方法来控制离散液体的运动。我们的策略是使用顺磁液体作为可变形的基底，利用磁场来引导各种浮动物体（包括裸液滴和液滴）的运动，磁场由小的永磁体产生，强度约为 50mT。广泛的液体，包括抗磁性（水，油）和非磁性液体，可以使用中等磁场（约 50mT）有效地输送。可以以可靠的方式实现复杂的轨迹，并通过按需液滴融合证明了复用的潜力。我们的顺磁流体方法的优点是无需任何复杂的设备或电力即可工作，这与稳健且低成本的分析和诊断流体设备的必要发展是一致的。
