Optical tweezers (OTs) have emerged as a powerful tool for probing emulsion dynamics with single-droplet precision, enabling quantitative analysis of interfacial interactions. Recent OT studies have systematically elucidated the critical factors governing emulsion stability, including ionic strength, pH, surfactant architecture, temperature, and photo/gas stimuli. Parallel advances in optofluidic control demonstrate that light-driven droplet rotation-achieved through angular momentum transfer and liquid crystal molecular reorientation represents a transformative approach for active soft matter manipulation. In this review, we conduct a systematic evaluation of OT systems, encompassing both instrumental configurations and cost-benefit analyses to assess their practical feasibility. The review critically examines the unique capabilities of OTs in emulsion research-including unprecedented spatial resolution and quantitative force measurement at the single-droplet level while addressing current limitations in throughput and operational complexity. Looking forward, the synergistic integration of OT technology with microfluidic platforms and machine learning algorithms is also presented.
Ma et al. (Thu,) studied this question.