We review the literature on swimming in complex fluids. A classification is proposed by comparing the length- and timescales of a swimmer with those of nearby obstacles, interpreted broadly, extending from rigid or soft confining boundaries to molecules that confer the bulk fluid with complex stresses. A third dimension in the classification is the concentration of swimmers, which incorporates fluids whose complexity arises purely by the collective motion of swimming organisms. For each of the eight system types that we identify, we provide a background and describe modern research findings. Although some types have seen a great deal of attention for decades, others remain uncharted waters still open and awaiting exploration.

中文翻译：

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在复杂流体中游泳


我们回顾了有关在复杂流体中游泳的文献。通过将游泳者的长度和时间尺度与附近障碍物的长度和时间尺度进行比较，提出了一种分类，从广义上解释，从刚性或软限制边界延伸到赋予大量流体复杂应力的分子。分类中的第三个维度是游泳者的集中度，其中包含流体，其复杂性纯粹由游泳生物体的集体运动产生。对于我们确定的八种系统类型中的每一种，我们都提供背景并描述现代研究结果。尽管某些类型几十年来一直受到广泛关注，但其他类型仍然是未知领域，等待探索。