Actuation of Janus Emulsion Droplets via Optothermally Induced Marangoni Forces
Actuation of Janus Emulsion Droplets via Optothermally Induced Marangoni Forces
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DOI：
10.1103/physrevlett.127.144503
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发表时间：
2021-09-29
影响因子：
8.6
通讯作者：
Kolle, Mathias
中科院分区：
文献类型：
--
作者：
Nagelberg, Sara;Totz, Jan F.;Kolle, Mathias
微型Janus乳剂是动态折射、反射和发光光学元件的通用材料平台。在这里，我们提出了一种机制，液滴驱动，利用热毛细作用。使用光学诱导的热梯度，跨Janus液滴的无表面活性剂的内部毛细管界面产生界面张力差。界面张力差导致液滴内部Marangoni流动和净扭矩，导致液滴的可预测和可控的重新取向。这种效应可以用一个平衡重力和热力矩的简单模型来定量描述。在小的热梯度下，这些光热诱导的Marangoni动力学是一种很有前途的机制，用于控制基于液滴的微光学元件。
Microscale Janus emulsions represent a versatile material platform for dynamic refractive, reflective, and light-emitting optical components. Here, we present a mechanism for droplet actuation that exploits thermocapillarity. Using optically induced thermal gradients, an interfacial tension differential is generated across the surfactant-free internal capillary interface of Janus droplets. The interfacial tension differential causes droplet-internal Marangoni flows and a net torque, resulting in a predictable and controllable reorientation of the droplets. The effect can be quantitatively described with a simple model that balances gravitational and thermal torques. Occurring in small thermal gradients, these optothermally induced Marangoni dynamics represent a promising mechanism for controlling droplet-based micro-optical components.