Dynamic Interfacial Printing Driven by Galvanometer Scanner for Monodisperse Single and Double Emulsion Droplets

Abstract Monodisperse micrometer‐sized droplets are essential in fields such as biochemical analysis and materials science, enabling applications like nucleic acid quantification and the synthesis of size‐controlled particles. While droplet microfluidic techniques offer excellent size uniformity and controllability, challenges in droplet size prediction and chip fabrication set certain barriers to its utilization in inexperienced labs. Alternatively, the dynamic interfacial printing (DIP) technique relying on a cross‐interface shearing process could generate droplets with predictable sizes via simple devices. However, traditional electromagnetic vibrators used in DIP systems are constrained by narrow and discontinuous frequency ranges, limiting their performance and application. To address this limitation, it is integrated a commercially available and low‐cost galvanometer scanner that can conduct precise reciprocating motion within a broad frequency spectrum into the DIP process. The resulting GS‐DIP system could generate monodisperse emulsion droplets at frequencies spanning from 1 to over 100 Hz. Furthermore, by incorporating a co‐axial capillary, the GS‐DIP system can produce double emulsion droplets with high uniformity and predictable size. This innovative approach provides robust technical support for advancing the development of the DIP technique but also unveils unprecedented possibilities for its potential application across diverse research fields.