Non-mechanical optical beam steering has received extraordinary attention in recent decades because it can steer a beam to a desired direction or location without moving parts. As a novel member of the non-mechanical beam steering method family, the liquid-based beam steering method exhibits some intriguing features. For example, this method is polarization-independent and has wide broadband, low power consumption, simple structure, and long lifetime. Many studies have been devoted to realizing optical beam steering based on liquid-based devices. This paper reviews the recent progress in this field. First, from the perspective of the working principles, the technical approaches are divided into the following four types: electrowetting effect, dielectrophoresis effect, tunable liquid lenses, and hydraulic control. The optical beam steering using liquid-based devices based on the electrowetting effect is reviewed from multiple aspects, including different sidewall shapes, multiple actuation electrodes, multiple liquid-liquid interfaces, and droplet movement. Moreover, the performances of the optical beam steering using liquid-based devices are compared, which provide a reference for readers to select the working principle to design the beam steering devices. Next, some representative applications of the beam steering device using liquid-based devices are presented, including optical switch, three-dimensional display, laser radar, solar tracking, indoor light, and microscopy. Finally, the challenges and outlook of optical beam steering using liquid-based devices are discussed. This review aims to provide a snapshot of the current state of the research field of optical beam steering using liquid-based devices to attract additional attention.

近几十年来，非机械光束转向受到了极大的关注，因为它可以将光束转向所需的方向或位置，而无需移动部件。作为非机械光束控制方法家族的新成员，基于液体的光束控制方法表现出一些有趣的特征。例如，这种方法与极化无关，具有宽带宽、功耗低、结构简单、寿命长等优点。许多研究致力于实现基于液体设备的光束控制。本文回顾了该领域的最新进展。首先，从工作原理来看，技术途径分为以下四种：电润湿效应、介电泳效应、可调液体透镜和液压控制。从不同的侧壁形状、多个驱动电极、多个液-液界面和液滴运动等多个方面综述了基于电润湿效应的基于液基器件的光束转向。此外，还比较了使用液基器件进行光束转向的性能，为读者选择工作原理设计光束转向装置提供参考。接下来，介绍了使用液基器件的光束转向装置的一些代表性应用，包括光开关、三维显示、激光雷达、太阳跟踪、室内光和显微镜。最后，讨论了使用基于液体的设备进行光束控制的挑战和前景。