Nakata Satoshi, Matsufuji Takero, Gorecki Jerzy, Kitahata Hiroyuki, Nishimori Hiraku
Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan.
Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
Phys Chem Chem Phys. 2020 Jun 17;22(23):13123-13128. doi: 10.1039/d0cp00746c.
We investigated self-propelled rotation of a symmetric three-bladed rotor on water under periodic halt and release operations. The rotation was driven by the difference in the surface tension around the blades of the rotor because camphor molecules developed from three camphor disks glued at the blade ends. Spontaneous inversion of rotation direction was observed after a forced stop of the rotor and the subsequent release. The probability of such inversion decreased with an increase in the halting time. The asymmetric distribution of camphor molecules around the blades was also inverted after the forced stop and the degree of asymmetry increased with an increase in the angular velocity characterizing the stationary rotation of the rotor. Our experimental results for rotors with different shapes indicate that there is a strong correlation between the stationary angular velocity of the rotor and the maximum time duration of the forced stop for which a high probability of inversion is observed.
我们研究了在周期性停止和释放操作下，对称三叶片转子在水面上的自推进旋转。这种旋转是由转子叶片周围表面张力的差异驱动的，因为从粘贴在叶片末端的三个樟脑盘上析出的樟脑分子造成了这种差异。在转子被迫停止并随后释放后，观察到旋转方向的自发反转。这种反转的概率随着停止时间的增加而降低。在被迫停止后，叶片周围樟脑分子的不对称分布也发生了反转，并且不对称程度随着表征转子稳定旋转的角速度的增加而增大。我们对不同形状转子的实验结果表明，转子的稳定角速度与观察到高反转概率的被迫停止的最长持续时间之间存在很强的相关性。
