T. (2019) High-throughput triggered merging of surfactant-stabilized droplet pairs using traveling surface acoustic waves. ABSTRACT: We present an acoustofluidic device for fluorescently triggered merging of surfactant-stabilized picoliter droplet pairs at high throughput. Droplets that exceed a preset fluorescence threshold level are selectively merged by a traveling surface acoustic wave (T-SAWs) pulse. We characterize the operation of our device by analyzing the merging efficiency as a

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... on of acoustic pulse position, duration and acoustic pressure amplitude. We probe droplet merging at different droplet rates and find that efficient merging occurs above a critical acoustic power level. Our results indicate that the efficiency of acoustically induced merging of surfactant stabilized droplets is correlated with acoustic streaming velocity. Finally, we discuss how both time-averaged and instantaneous acoustic pressure fields can affect the integrity of surfactant layers. Our technique, by allowing the merging of up to 10 5 droplets per hour, shows a great potential for integration into microfluidic systems for high-throughput and high-content screening applications.