Large‐Scale Deterministic Trapping and Arraying of Particles/Cells in Open Microfluidics

Abstract Hydrodynamic cell‐trapping techniques are widely used in single‐cell assays and screenings employing microfluidic technologies. However, in conventional “closed” microfluidic channels, it is not possible to pick cells selectively from the array, even though they have been arranged neatly. Previously, hydrodynamic deterministic trapping of ≈10‐µm particles (such as microbeads and cells) is demonstrated in an open microfluidic architecture driven by spontaneous capillary flow, where only the internal channel walls are made hydrophilic. It is shown that cell picking can be performed using a standard glass capillary. In this study, a microfluidic channel design is devised to increase the number of traps significantly compared with ≈100 in the previous study, achieving more than 10 000 traps. A method is developed to address the issue of decreased trapping yield caused by cell clogging, which is unavoidable in deterministic trapping. This technology is simple, effective, and has the potential to contribute to the broad application of single‐cell screening.