1. Research Background
With the continuous advancement of biomedical research toward high-throughput, precision, and personalized approaches, traditional experimental methods have shown obvious limitations in reaction volume, reagent consumption, and single-cell resolution. Achieving precise operations in ultra-small volumes while improving detection efficiency has become a core requirement for advancing life sciences. In this context, droplet microfluidics has rapidly emerged. This technology can generate highly uniform droplets in volumes ranging from picoliters to nanoliters and manipulate them at rates of tens of thousands per second, significantly reducing experimental costs while enhancing detection sensitivity. Thanks to these advantages, droplet microfluidics is gradually becoming an essential tool for single-cell analysis, drug screening, early disease detection, and the study of complex cellular behaviors, while also opening new technological pathways for future personalized medicine and clinical applications.

2. Research Focus
This review provides a comprehensive overview of the latest advances in droplet microfluidics, with a particular focus on its applications in drug discovery, disease diagnosis, and personalized medicine. The article systematically discusses droplet generation, manipulation, and detection techniques, comparing the advantages and limitations of each method. The review is organized into four main sections: droplet generation technologies, droplet manipulation strategies, droplet detection methods, and biomedical applications. Through this review, we aim to highlight the significant potential of droplet microfluidics in advancing biomedical research and clinical translation (Figure 1).

(1) Droplet Generation Technologies
Droplet generation is a core process in droplet microfluidic systems, fundamentally determining droplet size, uniformity, generation frequency, and compatibility with subsequent manipulation, detection, and specific applications. Droplet generation methods can be classified into passive and active approaches. Passive methods primarily rely on microchannel geometries and fluidic properties—such as viscosity, interfacial tension, and flow rate ratios—to form droplets; they are simple to operate and well-suited for continuous generation (Figure 2). Active methods, on the other hand, employ external physical fields—such as electric, magnetic, thermal, or mechanical forces—to precisely control droplet formation, enabling programmable, on-demand production of high-precision droplets that better meet complex experimental requirements and specific application needs.

(2) Droplet Manipulation Strategies
Precise droplet manipulation is critical for the broad applications of droplet microfluidics. Both traditional microchannel-based methods (Figure 3) and digital microfluidic technologies offer a variety of droplet manipulation strategies, including sorting, splitting, merging, capturing, and aggregation. These operations can meet the needs of applications ranging from basic biological experiments to high-throughput drug screening. Passive techniques mainly rely on microchannel geometries and fluidic properties. By designing channels with varying widths, branching structures, or flow rate ratios, droplets can be naturally separated or combined. These methods are simple to operate and suitable for continuous generation; however, their flexibility and controllability are relatively limited. In contrast, active methods employ external physical fields—such as electric, acoustic, magnetic, or other mechanical forces—to precisely control droplet formation and movement. This allows programmable, on-demand manipulation with high speed and precision, accommodating complex experimental requirements and diverse application scenarios. In recent years, the integration of emerging technologies such as triboelectric nanogenerators (TENGs), optoelectrowetting, and three-dimensional microstructures has further expanded the capabilities of droplet manipulation platforms. These innovations not only enhance flexibility and reproducibility but also provide new technological pathways for multimodal, high-throughput, and intelligent microfluidic systems.

(3) Droplet Detection
Droplet detection plays a critical role in enhancing the functionality of droplet microfluidic systems and expanding their range of applications. Different detection methods offer distinct advantages. Optical techniques provide high-resolution, real-time imaging, enabling visualization of dynamic processes within and between droplets. Mass spectrometry (MS) allows precise molecular-level analysis, facilitating the quantification and identification of biomolecules or chemical components (Figure 4). Electrical detection methods support label-free, easily integrable, and highly sensitive monitoring, suitable for continuous detection and miniaturized systems. Additionally, detection strategies based on triboelectric nanogenerators (TENGs) introduce an innovative, self-powered, and non-invasive approach, enhancing both energy efficiency and operational convenience for microfluidic systems.
The integration of multiple detection techniques not only improves accuracy, throughput, and reliability but also significantly expands the potential applications of droplet microfluidics in biomedical diagnostics, environmental monitoring, drug development, and single-cell analysis.

(4) Applications of Droplet Microfluidics
Droplet microfluidics demonstrates tremendous potential across multiple fields, particularly in single-cell analysis, three-dimensional (3D) cell culture (Figure 4), drug development, and disease prevention. By precisely controlling droplet generation, movement, and distribution, this technology enables efficient single-cell-level analysis, revealing key biological processes such as cellular heterogeneity and gene expression.
In 3D cell culture, droplet microfluidics provides an ideal platform for simulating the in vivo microenvironment, promoting the development of more physiologically relevant cell models. In drug development, it accelerates high-throughput screening and enables rapid reaction monitoring, thereby expediting the discovery of new therapeutics. Additionally, in the field of disease prevention and treatment, droplet microfluidics plays a vital role in rapid diagnostics and the design of personalized treatment strategies.

3. Future Perspectives
With ongoing technological advancements and increasing application demands, droplet microfluidics is becoming an essential tool in biomedical research, environmental monitoring, and materials science. Future developments are expected to focus on multifunctional integration, self-powered systems, intelligent and automated operation, and expanded applications.
Multifunctional integration aims to combine droplet generation, manipulation, detection, and reactions within a single system, improving experimental efficiency and flexibility while reducing sample contamination and equipment costs.
Self-powered systems, enabled by technologies such as triboelectric nanogenerators (TENGs), allow microfluidic devices to operate efficiently in outdoor or power-limited environments.
Intelligent and automated systems leverage machine learning and data analytics to monitor and optimize droplet flow and reactions in real time, enhancing accuracy and minimizing human error.
Expanded applications are driving the use of microfluidics in biomarker detection, drug screening, single-cell analysis, and rapid analysis of environmental samples, supporting precision medicine and environmental management.
Overall, through multifunctional integration, self-powered operation, and intelligent automation, droplet microfluidics is poised to significantly enhance experimental efficiency and precision, while broadening its potential applications in research, industry, and environmental monitoring to meet the growing demands for rapid, real-time, and personalized solutions.

The complete study is accessible via DOI:10.34133/research.0856