We experimentally study the stochastic transport of a self-propelled camphor boat, driven by Marangoni forces, through a crowd of passive paper discs floating on water. We analyze the statistics of the first passage times of the active particle to travel from the center of a circular container to its boundary. While the mean times rise monotonically as a function of the covered area fraction ϕ of the passive paper discs, their fluctuations show a non-monotonic behavior – being higher at low and high value of ϕ compared to intermediate values. The reason is traced to an interplay of two distinct sources of fluctuations – one intrinsic to the dynamics, while the other due to the crowding.

中文翻译：

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主动粒子在被动拥挤者存在下的第一次通过。

我们实验研究了由Marangoni部队驱动的自行式樟脑船通过大量漂浮在水面上的被动纸碟的随机运输。我们分析了活性颗粒从圆形容器的中心到其边界的第一次通过时间的统计数据。而平均倍单调上升为覆盖面积分数的函数φ被动纸圆盘，它们的波动示出了非单调行为-处于低和高值高φ相比中间值。原因可以追溯到两个不同的波动源之间的相互作用-一个是动态固有的，而另一个是由于拥挤。