Braniste Tudor, Ciobanu Vladimir, Schütt Fabian, Mimura Hidenori, Raevschi Simion, Adelung Rainer, Pugno Nicola M, Tiginyanu Ion
National Center for Materials Study and Testing, Technical University of Moldova, Stefan cel Mare Av. 168, 2004 Chisinau, Moldova.
Institute for Materials Science, Kiel University, Kaiserstr. 2, 24143 Kiel, Germany.
Materials (Basel). 2021 Sep 6;14(17):5086. doi: 10.3390/ma14175086.
We report on self-propelled rotating liquid marbles fabricated using droplets of alcoholic solution encapsulated in hollow microtetrapods of GaN with hydrophilic free ends of their arms and hydrophobic lateral walls. Apart from stationary rotation, elongated-spheroid-like liquid marbles were found, for the first time, to exhibit pulsed rotation on water surfaces characterized by a threshold speed of rotation, which increased with the weight of the liquid marble while the frequency of pulses proved to decrease. To throw light upon the unusual behavior of the developed self-propelled liquid marbles, we propose a model which takes into account skimming of the liquid marbles over the water surface similar to that inherent to flying water lily beetle and the so-called helicopter effect, causing a liquid marble to rise above the level of the water surface when rotating.
我们报道了利用封装在氮化镓空心微四足体中的酒精溶液液滴制备的自驱动旋转液体弹珠，这些微四足体的臂端具有亲水性，侧壁具有疏水性。除了静止旋转外，首次发现类似细长球体的液体弹珠在水面上呈现脉冲旋转，其特征为存在一个旋转阈值速度，该速度随液体弹珠的重量增加而增大，而脉冲频率则降低。为了阐明所制备的自驱动液体弹珠的异常行为，我们提出了一个模型，该模型考虑了液体弹珠在水面上的掠过，类似于水黾所具有的特性，以及所谓的直升机效应，即液体弹珠旋转时会升至水面之上。
