Dipartimento di Fisica e Astronomia "G. Galilei" , Università di Padova , via Marzolo 8 , 35131 Padova , Italy.
Sorbonne Université, CNRS, Laboratoire Physico-Chimie des Electrolytes et Nanosystèmes, PHENIX , F-75005 Paris , France.
Langmuir. 2018 Jul 31;34(30):8917-8922. doi: 10.1021/acs.langmuir.8b01520. Epub 2018 Jul 18.
The motion of liquid drops on solid surfaces is attracting a lot of attention because of its fundamental implications and wide technological applications. In this article, we present a comprehensive experimental study of the interaction between gravity-driven ferrofluid drops on very slippery oil-impregnated surfaces and a patterned magnetic field. The drop speed can be accurately tuned by the magnetic interaction, and more interestingly, drops are found to undergo a stick-slip motion whose contrast and phase can be easily tuned by changing either the strength of the magnetic field or the ferrofluid concentration. This motion is the result of the periodic modulation of the external magnetic field and can be accurately analyzed because the intrinsic pinning due to chemical defects is negligible on oil-impregnated surfaces.
由于其基本意义和广泛的技术应用，液体滴在固体表面上的运动引起了人们的极大关注。在本文中，我们对重力驱动的铁磁液滴在非常光滑的油浸渍表面和图案化磁场之间的相互作用进行了全面的实验研究。通过磁相互作用可以精确地调节液滴的速度，更有趣的是，发现液滴会经历一个粘滑运动，其对比度和相位可以通过改变磁场的强度或铁磁流体的浓度来轻松调节。这种运动是外部磁场的周期性调制的结果，可以进行精确地分析，因为在油浸渍的表面上，由于化学缺陷引起的固有钉扎作用可以忽略不计。
