This review treats asymmetric colloidal particles moving through their host fluid under the action of some form of propulsion. The propulsion can come from an external body force or from external shear flow. It may also come from externally-induced stresses at the surface, arising from imposed chemical, thermal or electrical gradients. The resulting motion arises jointly from the driven particle and the displaced fluid. If the objects are asymmetric, every aspect of their motion and interaction depends on the orientation of the objects. This orientation in turn changes in response to the driving. The objects' shape can thus lead to a range of emergent anisotropic and chiral motion not possible with isotropic spherical particles. We first consider what aspects of a body's asymmetry can affect its drift through a fluid, especially chiral motion. We next discuss driving by injecting external force or torque into the particles. Then we consider driving without injecting force or torque. This includes driving by shear flow and driving by surface stresses, such as electrophoresis. We consider how time-dependent driving can induce collective orientational order and coherent motion. We show how a given particle shape can be represented using an assembly of point forces called a Stokeslet object. We next consider the interactions between anisotropic propelled particles, the symmetries governing the interactions, and the possibility of bound pairs of particles. Finally we show how the collective hydrodynamics of a suspension can be qualitatively altered by the particles' shapes. The asymmetric responses discussed here are broadly relevant also for swimming propulsion of active micron-scale objects such as microorganisms.

中文翻译：

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流体中成形胶体颗粒的综述：各向异性和手性

这篇综述讨论了在某种形式的推进作用下穿过宿主流体的不对称胶体粒子。推进力可以来自外部体力或外部剪切流。它也可能来自表面的外部感应应力，由施加的化学、热或电梯度引起。由此产生的运动是由被驱动的粒子和被置换的流体共同产生的。如果对象是不对称的，则它们的运动和交互的每个方面都取决于对象的方向。该方向又随着驾驶而改变。因此，物体的形状会导致一系列各向异性和手性运动，这是各向同性的球形粒子不可能实现的。我们首先考虑物体不对称的哪些方面会影响它在流体中的漂移，尤其是手性运动。我们接下来讨论通过将外力或扭矩注入粒子来驱动。然后我们考虑在没有注入力或扭矩的情况下驱动。这包括剪切流驱动和表面应力驱动，例如电泳。我们考虑了依赖时间的驾驶如何诱导集体定向顺序和连贯运动。我们展示了如何使用称为 Stokeslet 对象的点力集合来表示给定的粒子形状。我们接下来考虑各向异性推进粒子之间的相互作用、控制相互作用的对称性以及结合粒子对的可能性。最后，我们展示了悬浮液的集体流体动力学如何通过颗粒形状进行定性改变。