Efficient Cell Trapping by Diffusiophoretic Transport into Dead‐End Chambers

The efficient and stable capture of cells within microfluidic platforms is essential for cellular biology analyses, offering insights into the heterogeneity of cell properties and cellular processes, for example, among cancer cells. However, conventional microfluidic cell confinement modalities, such as water‐in‐oil emulsions and microstructure trapping, face inherent limitations in biological applicability and precise control. Here an approach is introduced to confine cells in dead‐end microstructures leveraging a dextran concentration gradient. This method allows for the fine‐tuned capture of cells, reaching the precision of single‐cell culture, as demonstrated for yeast and leukemia cells. By incorporating polyethylene glycol (PEG) solutions, phase separation is induced within the microfluidic environment, encapsulating single cells within dextran droplets. The technique is distinguished by its stability, control, and adaptability, paving a new way for innovations not only in cellular biology, but broadly in chemical and biological applications, including the synthesis of bio‐oriented particles, microcarrier production, and advancements in tissue engineering.