Holographic Optical Tweezers (HOT) are powerful tools that can manipulate micro and nano-scale objects with high accuracy and precision. They are most commonly used for biological applications, such as cellular studies, and more recently, micro-structure assemblies. Automation has been of significant interest in the HOT field, since human-run experiments are time-consuming and require skilled operator(s). Automated HOTs, however, commonly use point traps, which focus high intensity laser light at specific spots in fluid media to attract and move micro-objects. In this paper, we develop a novel automated system of tweezing multiple micro-objects more efficiently using multiplexed optical traps. Multiplexed traps enable the simultaneous trapping of multiple beads in various alternate multiplexing formations, such as annular rings and line patterns. Our automated system is realized by augmenting the capabilities of a commercially available HOT with real-time bead detection and tracking, and wavefront-based path planning. We demonstrate the usefulness of the system by assembling two different composite micro-structures, comprising 5 $\mu m$ polystyrene beads, using both annular and line shaped traps in obstacle-rich environments.

翻译：全息光镊（HOT）能以高精度操控微纳米尺度物体，广泛应用于生物领域（如细胞研究）及近年兴起的微结构组装。由于人工实验耗时且依赖操作人员经验，自动化成为该领域的研究热点。然而，现有自动化HOT系统通常采用点状光阱，通过高功率激光聚焦于流体介质特定位置来吸引与移动微物体。本文提出一种基于复用光阱的新型自动化多微物体操控系统。复用光阱可同时捕获多个微珠，并形成环形、线形等交替复用结构。通过增强商用HOT系统的实时微珠检测追踪与波前路径规划能力，本文实现了一种自动化操控方案。在障碍密集环境中，我们分别利用环形与线形光阱成功组装了5微米聚苯乙烯微珠构成的两种复合微结构，验证了该系统的实用性。