Microswimmers are sub-millimeter swimming microrobots that show potential as a platform for controllable locomotion in applications including targeted cargo delivery and minimally invasive surgery. To be viable for these target applications, microswimmers will eventually need to be able to navigate in environments with dynamic fluid flows and forces. Experimental studies with microswimmers towards this goal are currently rare because of the difficulty isolating intentional microswimmer motion from environment-induced motion. In this work, we present a method for measuring microswimmer locomotion within a complex flow environment using fiducial microspheres. By tracking the particle motion of ferromagnetic and non-magnetic polystyrene fiducial microspheres, we capture the effect of fluid flow and field gradients on microswimmer trajectories. We then determine the field-driven translation of these microswimmers relative to fluid flow and demonstrate the effectiveness of this method by illustrating the motion of multiple microswimmers through different flows.

翻译：微游动机器人是亚毫米级游泳微型机器人，作为可控运动平台在靶向货物递送和微创手术等应用中展现出潜力。为实现这些目标应用，微游动机器人最终需要能够在具有动态流体流动和力的环境中导航。目前针对该目标的微游动机器人实验研究较为罕见，主要难点在于难以将主动微游泳运动与环境诱导运动分离。本研究提出了一种利用基准微球测量复杂流动环境中微游动机器人运动的方法。通过追踪铁磁性与非磁性聚苯乙烯基准微球的粒子运动，我们捕获了流体流动与场梯度对微游动机器人轨迹的影响。随后确定了这些微游动机器人相对于流体流动的场驱动平移，并通过展示多个微游动机器人在不同流动中的运动验证了该方法的有效性。