Photonics and Optoelectronics Group, Department of Physics and Center of Nanoscience (CeNS), Ludwig-Maximilians-Universität München, 80799 Munich, Germany.
Soft Matter. 2018 Jan 24;14(4):628-634. doi: 10.1039/c7sm01863k.
Optothermal control of fluid motion has been suggested as a powerful way of controlling nanomaterials in micro- or nanofluidic samples. Methods based on merely thermal convection, however, often rely on high temperature for achieving fluid velocities suitable for most practical uses. Here, we demonstrate an optofluidic approach based on Marangoni or thermocapillary convection to steer and manipulate nano-objects with high accuracy at an air/liquid interface. By experiments and numerical simulations, we show that the fluid velocities achieved by this approach are more than three orders of magnitude stronger compared to natural convection and that it is possible to control the transport and position of single plasmonic nanoparticles over micrometer distances with high accuracy.
光热控制流体运动被认为是控制微纳流控样品中纳米材料的一种有效方法。然而，基于单纯热对流的方法往往需要高温才能达到适用于大多数实际应用的流体速度。在这里，我们展示了一种基于 Marangoni 或热毛细对流的光流控方法，用于在气/液界面上以高精度引导和操纵纳米物体。通过实验和数值模拟，我们表明，与自然对流相比，这种方法实现的流体速度要强三个数量级以上，并且可以高精度地控制单个等离子体纳米颗粒在微米距离内的输运和位置。
