Abstract
Double emulsions, with core-shell structures, are versatile materials used in diverse applications such as cell culture, drug delivery, and materials synthesis. A library of double emulsions with precisely controlled dimensions and properties would streamline the process of screening and optimization for specific applications. Microfluidic droplet generation offers precise control over droplet dimensions and properties, making it ideal for the preparation of droplet libraries; however, their preparation is tedious because fluid flow control and emulsion collection are typically performed manually and microfluidic devices are vulnerable to minor disturbances, requiring continuous intervention by skilled operators. To address these challenges, we present an artificial intelligence (AI)-empowered automated double emulsion droplet library generator. Leveraging a convolutional neural network (CNN)-based object detection model fine-tuned on a custom dataset, the system integrates decision-making and feedback control for automated droplet generation and collection. The system monitors droplet generation every 171 ms —faster than the reaction time of Formula 1 drivers —ensuring rapid response to disruptions and consistent production of single-core double emulsions. The library generator autonomously generates libraries consisting of 25 distinct monodisperse droplets with user-specified properties. This system significantly improves droplet-based experiments by reducing labor and waste, improving precision, and supporting rapid, reliable droplet library generation.
Supplementary materials
Title
Supporting Information
Description
Supporting figures, their discriptions, and captions for supproting videos
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Title
Video S1. Failure of double emulsion generation
Description
In this video, MP mode occurs spontaneously, leading to failure in double emulsion generation.
The droplet generator used has the following geometry: DIjt = 61.5, DClt = 123, L = 89.3 μm and,
θ=2.3 °. Flow rates for the inner, middle, and outer phases were set to 2, 0.75, and 40 mL/hr,
respectively.
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Video S2. Effect of product selector movement in droplet generation
Description
The top section of the video shows droplet generation while the product selector alternates
between "collection" and "waste" positions every 0.5 seconds. The bottom section displays droplet
generation without product selector movement. Flow rates for inner phase 1 and the middle phase
were set to 2 and 0.5 mL/hr, respectively, with an outer phase pressure of 100 mbar.
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Video S3. Single-core double emulsion generation recovery process
Description
This video shows droplet generation with overlaid detection results. MP mode occurs
spontaneously. Flow rates for inner phase 1 and 2, and the middle phase were set to 1.7, 0.3, and
0.5 mL/hr, respectively.
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Video S4. Demonstration of graphical user interface 1
Description
This video demonstrates the initiation of automated double emulsion droplet library generation
using the GUI. The experiments shown in the video are based on the same user input as described
in Figures 5, 6, and Video S6. This version of the GUI accepts minimum and maximum
concentration values and calculates five linearly spaced concentrations between them.
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Video S5. Demonstration of graphical user interface 2
Description
This video demonstrates the initiation of automated double emulsion droplet library generation
using the GUI when the initial droplet generation mode is MP. In this version of the GUI, users
can input five specific concentration values.
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Video S6. Automated generation of double emulsion droplet library
Description
This time-lapse video shows the generation process of a 5 × 5 droplet library. Results from this
experiment are presented in Figures 5 and 6 in the main text.
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