Selmke Markus, Khadka Utsab, Bregulla Andreas P, Cichos Frank, Yang Haw
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
Peter Debye Institute for Soft Matter Physics, Universität Leipzig, 04103 Leipzig, Germany.
Phys Chem Chem Phys. 2018 Apr 18;20(15):10502-10520. doi: 10.1039/C7CP06559K.
Photon nudging is a new experimental method which enables the force-free manipulation and localization of individual self-propelled artificial micro-swimmers in fluidic environments. It uses a weak laser to stochastically and adaptively turn on and off the swimmer's propulsion when the swimmer, through rotational diffusion, points towards or away from its target, respectively. This contribution presents a theoretical framework for the statistics of both 2D and 3D controls. The main results are: the on- and off-time distributions for the controlling laser, the arrival time statistics for the swimmer to reach a remote target, and how the experimentally accessible control parameters influence the control, e.g., the optimal acceptance angle for directed transport. The results are general in that they are independent of the propulsion or the actuation mechanisms. They provide a concrete physical picture for how a single artificial micro-swimmer could be navigated under thermal fluctuations-insights that could also be useful for understanding biological micro-swimmers.
光子微扰是一种新的实验方法，它能够在流体环境中对单个自行推进的人造微游动体进行无外力操纵和定位。当微游动体通过旋转扩散分别指向或远离其目标时，该方法使用弱激光随机且自适应地开启和关闭微游动体的推进。本文给出了二维和三维控制统计的理论框架。主要结果包括：控制激光的开启和关闭时间分布、微游动体到达远程目标的到达时间统计，以及实验可获取的控制参数如何影响控制，例如定向传输的最佳接受角。这些结果具有普遍性，因为它们与推进或驱动机制无关。它们为单个仿微生物微游动体在热涨落情况下的导航提供了具体的物理图景，这些见解对于理解生物微游动体也可能有用。
