Biological or artificial microswimmers move performing trajectories of different kinds such as rectilinear, circular, or spiral ones. Here, we report on circular trajectories observed for active Janus colloids trapped at the air–water interface. Circular motion is due to asymmetric and nonuniform surface properties of the particles caused by fabrication. Motion persistence is enhanced by the partial wetted state of the Janus particles actively moving in two dimensions at the air–water interface. The slowing down of in-plane and out-of-plane rotational diffusions is described and discussed.

中文翻译：

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Janus胶体在水表面上主动旋转

生物或人工微游泳者会移动不同类型的执行轨迹，例如直线，圆形或螺旋形。在这里，我们报告了在空气-水界面处捕获的活动Janus胶体观察到的圆形轨迹。圆周运动是由于制造引起的颗粒的不对称和不均匀的表面性质。Janus颗粒的部分润湿状态在空气-水界面处以二维方式主动运动，从而增强了运动持久性。描述和讨论了平面内和平面外旋转扩散的减慢。